Question Desktop PC powers on only with air conditioner turned on ?

[pandre]

My desktop pc fails to start (mainly in the morning) after being off for some hours. It only starts if I power on the air conditioner for some minutes. What can be the problem?

Additional info (January 17, 2023): I noticed that whenever powered up with the air conditioner on, the clock loses its settings. I will buy a new battery, but I am not sure if this will be of any help.
Another point, the problem started some 8 months ago and I have tried every suggestion I could find on the web. Two months ago someone suggested that the problem might be caused by high humidity. I put some dehumidifier inside the PC case and it helped (the PC was able to power on) but this did not last and soon the PC would not power up. I checked the level of water in the dehumidifier and exchanged it for a new one. Did not work! That was when it occurred to me that the air conditioning may be of help as it would remove the excessive dampness. And, it worked.
So, I believe that the problem might be caused by dampness. I live in Rio de Janeiro and since last July our weather has been very rainy.

 

[Pyrostemplar]

Have you tried using a UPS?

 

[pandre]

Have you tried using a UPS?

I am using one but it does not have any influence!

 

[pandre]

Odd. Have you tried connecting your PC to a different electrical outlet?

Yes, to several others.

 

[pandre]

Perhaps the pins for the power button are corroded and or dirty on the motherboard. Try sliding the contacts up and down a bit.... Tough to really nail it down, a contact somewhere is not happy.

In my opinion is not a contact as I have moved and even punched the case but it did not hang or displayed any error message!

 

[pandre]

My desktop pc fails to start (mainly in the morning) after being off for some hours. It only starts if I power on the air conditioner for some minutes. What can be the problem?

Additional info (January 17, 2023): I noticed that whenever powered up with the air conditioner on, the clock loses its settings. I will buy a new battery, but I am not sure if this will be of any help.
Another point, the problem started some 8 months ago and I have tried every suggestion I could find on the web. Two months ago someone suggested that the problem might be caused by high humidity. I put some dehumidifier inside the PC case and it helped (the PC was able to power on) but this did not last and soon the PC would not power up. I checked the level of water in the dehumidifier and exchanged it for a new one. Did not work! That was when it occurred to me that the air conditioning may be of help as it would remove the excessive dampness. And, it worked.
So, I believe that the problem might be caused by dampness. I live in Rio de Janeiro and since last July our weather has been very rainy.

I bought and installed a new CMOS battery. No effect whatsoever!

 

[Pyrostemplar]

I am using one but it does not have any influence!

Ok, if the UPS is working that rules out electrical source issues.
Humidity causing an electrical issue seems to me the most obvious possibility. Have you tried using an hair drier, just as a test?

 

[pandre]

Does the PC get ANY power when the AC is off?

Yes. The lights on the motherboards are on.

 

[pandre]

I did put two silica packets but they only worked for about one week. Then either the problem worsened or the packets lost their absorption capability.

I did not blow the PSU. I blown the the motherboard with a hot hair drier, but it did not work (I did not blow for a long time, afraid that it my damage the solder or some component).

The front of the case switch is OK.

I bought and installed a new and different brand of power supply to no avail.

Thanks.

Correction. I tried the hair drier for about 5 minutes and the PC powered on. The first time I only tried for two to three minutes.

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition (original to build, new, refurbished, used)?

Disk drive(s): make model, capacity, how full?

= = = =

How close is the air conditioner to the PC? Does the air conditioner blow directly on the PC or just near by?

Consider that there could be two problems: the first problem when PC is "too warm" and the second problem when the PC is "too cool".

And the end result being a matter of expansion or contraction. Something loose tightens (expansion) and regains connectivity. Something tight connected (contracts) and looses connectivity.

All being intermittment and a function of temperature. Vibrations and case air flows may be involved.

Sort of a perfect storm scenerio. Or Gremlins....

Worth a look into Reliability History and Event Viewer for error codes, warnings, and informational events that may be associated with the failures.

= = = =

Power down the PC, unplug, open the case.

Clean out dust and debris.

Verify by sight and feel that all connections, cards, RAM, jumpers, and case connectors are fully and firmly in place.

Use a bright flashlight to inspect for any signs of damage: bare conductor showing, melting, kinked or pinched wires, loose or missing screws, browned or blackened components/areas. GPU sagging, fan blades - dirty, cracked, blocked. Corrosion. Swollen components, scratches, solder joints, any physical damage at all.

= = = =

Revert to a bare bones build with the objective of achieving a reliable pc power on that is independent of air conditioning.

Take your time, be methodical, double check everything (User Guides/Manuals), keep notes. Change only one thing at a time allowing time between changes.

Key is to discover patterns and/or results that can be duplicated at will: If X then pc consistently powers on. If not X then pc fails to consistently power on.

Doing so is going to take some time and effort.

 

[pandre]

Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition (original to build, new, refurbished, used)?

Disk drive(s): make model, capacity, how full?

= = = =

How close is the air conditioner to the PC? Does the air conditioner blow directly on the PC or just near by?​

Consider that there could be two problems: the first problem when PC is "too warm" and the second problem when the PC is "too cool".

And the end result being a matter of expansion or contraction. Something loose tightens (expansion) and regains connectivity. Something tight connected (contracts) and looses connectivity.

All being intermittment and a function of temperature. Vibrations and case air flows may be involved.

Sort of a perfect storm scenerio. Or Gremlins....

Worth a look into Reliability History and Event Viewer for error codes, warnings, and informational events that may be associated with the failures.

= = = =

Power down the PC, unplug, open the case.

Clean out dust and debris.

Verify by sight and feel that all connections, cards, RAM, jumpers, and case connectors are fully and firmly in place.

​

Use a bright flashlight to inspect for any signs of damage: bare conductor showing, melting, kinked or pinched wires, loose or missing screws, browned or blackened components/areas. GPU sagging, fan blades - dirty, cracked, blocked. Corrosion. Swollen components, scratches, solder joints, any physical damage at all.

= = = =

Revert to a bare bones build with the objective of achieving a reliable pc power on that is independent of air conditioning.

Take your time, be methodical, double check everything (User Guides/Manuals), keep notes. Change only one thing at a time allowing time between changes.

Key is to discover patterns and/or results that can be duplicated at will: If X then pc consistently powers on. If not X then pc fails to consistently power on.

Doing so is going to take some time and effort.

Update your post to include full system hardware specs and OS information.

The link below have most of information you asked and then some...​

PandreHardware​

Include PSU: make, model, wattage, age, condition (original to build, new, refurbished, used)?

Maker: MyMax​

Model: ATX 500W 80+ Bronze​

Wattage: 500W​

Age: 1 year and 3 months​

Condition: New​

​

Disk drive(s): make model, capacity, how full?

Disk drivers: Maker: Acclamator SS 512GB ​

Seagate ST1000DM010-2EP102 (1TB)​

Link with more details: DiskDrives​

​

= = = =

How close is the air conditioner to the PC? Does the air conditioner blow directly on the PC or just near by?

Air conditioner: About three meters away from computer​

Does not blow directly on the PC​

The air conditioner is a 220V unit and the PC is 110V​

​

Consider that there could be two problems: the first problem when PC is "too warm" and the second problem when the PC is "too cool".

I live in Rio de Janeiro. I don'nt think there is a "too cool" weather around here. However, "too hot and damp" is , sometimes the case.​

​

And the end result being a matter of expansion or contraction. Something loose tightens (expansion) and regains connectivity. Something tight connected (contracts) and looses connectivity.

All being intermittment and a function of temperature. Vibrations and case air flows may be involved.

Sort of a perfect storm scenerio. Or Gremlins....

Worth a look into Reliability History and Event Viewer for error codes, warnings, and informational events that may be associated with the failures.

Looked into reliability history but could not get any clue from there.​

Event viewer has quite a few Event 41, Kernel-Power. General description: The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly. ​

Below are list of EventData. I am unable to interpret them.​

- EventData ​

BugcheckCode 209 ​

BugcheckParameter1 0x28 ​

BugcheckParameter2 0x0 ​

BugcheckParameter3 0x0 ​

BugcheckParameter4 0x0 ​

SleepInProgress 0 ​

PowerButtonTimestamp 0 ​

BootAppStatus 0 ​

Checkpoint 16 ​

ConnectedStandbyInProgress true ​

SystemSleepTransitionsToOn 1 ​

CsEntryScenarioInstanceId 13 ​

BugcheckInfoFromEFI true ​

CheckpointStatus 0 ​

CsEntryScenarioInstanceIdV2 13 ​

LongPowerButtonPressDetected false ​

LidReliability false ​

InputSuppressionState 0 ​

PowerButtonSuppressionState 0 ​

LidState 3 ​

There are 19,009 administrative events​

Most of them are "Event 7, disk" with the general description "The device, \Device\Harddisk1\DR1, has a bad block."​

The first instance of the event is dated: 08/10/2022 17:48:05​

The second more frequent is: ​

"Autopilot.dll WIL error was reported.​

HRESULT: 0x80070491​

File: onecoreuap\admin\moderndeployment\autopilot\dll\dllmain.cpp, line 128​

Message: NULL​

​

= = = =

Power down the PC, unplug, open the case.

Clean out dust and debris.

Verify by sight and feel that all connections, cards, RAM, jumpers, and case connectors are fully and firmly in place.

​

Use a bright flashlight to inspect for any signs of damage: bare conductor showing, melting, kinked or pinched wires, loose or missing screws, browned or blackened components/areas. GPU sagging, fan blades - dirty, cracked, blocked. Corrosion. Swollen components, scratches, solder joints, any physical damage at all.

I did the above recommendation except by cleaning the dust as there was almost none.
I tighten all screws that hold the motherboard (some of them were almost loose).​

I did not find any loose connection, card jumpers, case connectors. They all seemed to be firmly in place.​

I could not signs of damage, corrosion, swollen components, scratches, solder joint or any other physical damage.​

​

= = = =

Revert to a bare bones build with the objective of achieving a reliable pc power on that is independent of air conditioning.

I will do this tomorrow morning before powering on the air conditioner and having the PC in the same situation that the problem happens.
By "Revert to bare bones" I believe you mean disconnecting everything but memory (including the disk drives). Right?​

Take your time, be methodical, double check everything (User Guides/Manuals), keep notes. Change only one thing at a time allowing time between changes.

Key is to discover patterns and/or results that can be duplicated at will: If X then pc consistently powers on. If not X then pc fails to consistently power on.

Doing so is going to take some time and effort.

+=+=+=+=+=+
Thanks for your help!

 

[Ralston18]

The PandreHardware "specs" link appears to be hosted on OneDrive (?) and opens into HTML text.

Which drive is "The device, \Device\Harddisk1\DR1, has a bad block." per Disk Management?

In Event Viewer delete the logs to get an easier and fresher look at ongoing errors.

The error code description clearly indicates power problems.

- - - -

In Reliability History set the timeline to "Days".

Select a date that is representative of the error codes, warning, and informational events presented. Red, yellow, blue icons.

Expand the Reliability History window so all can be seen. Take a screenshot and post the screenshot here via imgur (www.imgur.com). Use imgur for all images.

Air Conditioner:

In agreement with @COLGeek regarding a potential electrical problem. There should be absolutely no dependency on whether or not the AC is running.

220 volts and 110 volts - how that is being done needs to be professionally checked.

And having a UPS may be adding to the problem(s). The UPS may or may not be respondingly quickly enough to cover power losses or brief voltage drops.

What all else is plugged into the UPS? Any other surge protectors, power strips, extension cords? You may have an electrical ground loop involved.

The UPS's surge protection, if any, may be gone. Surge protection is measured in Joules and is cumulative. Previous power surges may have saved the protected equipment for awhile. Reached max protection. Now, little or no protection. UPS could be damaged as well.

Therefore the PC - and the disk drive in particular is now taking the hits that are physically damaging the drive and/or corrupting data.

Very likely other system components are being stressed.

Summary: Get the electrical system inspected and checked. All circuits, outlets, and connected devices.

Some problem or potentially worsening problem will not end well.

 

[pandre]

The PandreHardware "specs" link appears to be hosted on OneDrive (?) and opens into HTML text.

Right. It is hosted on my OneDrive.​

Which drive is "The device, \Device\Harddisk1\DR1, has a bad block." per Disk Management?

This the Seagate 1TB drive. I am sending the imgur link to the disk management​

https://imgur.com/aQxxa5o

View: https://imgur.com/aQxxa5o
​

In Event Viewer delete the logs to get an easier and fresher look at ongoing errors.

Event viewer cleared.​

The error code description clearly indicates power problems.

Let us see what happens tomorrow.​

- - - -

In Reliability History set the timeline to "Days".

It was already set to days.​

Select a date that is representative of the error codes, warning, and informational events presented. Red, yellow, blue icons.

OK. See below.​

Expand the Reliability History window so all can be seen. Take a screenshot and post the screenshot here via imgur (www.imgur.com). Use imgur for all images.

Below are "imgur" links to Reliability history of two days​

https://imgur.com/ApPOz75

View: https://imgur.com/ApPOz75
​

https://imgur.com/8hwnSDe

View: https://imgur.com/8hwnSDe
​

Air Conditioner:

In agreement with @COLGeek regarding a potential electrical problem. There should be absolutely no dependency on whether or not the AC is running.

The dependency is not on the air conditioner being on or off but on the fact that it removes humidity. As I said before I was able to power on the PC by blowing hot air on the motherboard with a hair drier.​

220 volts and 110 volts - how that is being done needs to be professionally checked.

My apartment is wired in such a way that some outlets are for 220V (specially for air conditioner). this is common here in Brazil. I mentioned that just to make sure that the PC and the air conditioner are in different circuits. Speaking about "...need to be professionally checked." I believe to be able to ensure you of this as I am an Electronic Engineer.​

Another info: I timed how long it takes after powering up the air conditioner and being able to power up the PC: it took 10 minutes for the PC to power up and start the boot process (I was constantly pressing the PC power button and it only powered on after these 10 minutes.​

And having a UPS may be adding to the problem(s). The UPS may or may not be respondingly quickly enough to cover power losses or brief voltage drops.

One of my first action (some months ago) was to bypass the UPS (which is by the of a Brazilian brand "INTELBRAS") and connected the PC directly to the power outlet, but it did not help.​

What all else is plugged into the UPS? Any other surge protectors, power strips, extension cords? You may have an electrical ground loop involved.

Nothing else is plugged on the UPS.​

The UPS's surge protection, if any, may be gone. Surge protection is measured in Joules and is cumulative. Previous power surges may have saved the protected equipment for awhile. Reached max protection. Now, little or no protection. UPS could be damaged as well.

As told above, I already connected the PC directly to the power outlet, bypassing the UPS, to no avail.​

Therefore the PC - and the disk drive in particular is now taking the hits that are physically damaging the drive and/or corrupting data.

OK. Just to avoid any doubt about the UPS, I just, once again, bypassed it and connect the PC directly to the power outlet.​

Ah! Another piece of information, I checked the voltage on the power outlet and it is at 128.8 V.​

I will have to wait till tomorrow morning to power on the PC again in the same situation.​

​

​

Very likely other system components are being stressed.

That is also my fear!​

Summary: Get the electrical system inspected and checked. All circuits, outlets, and connected devices.

I checked it again today. Found no problem.​

As said above the voltage is OK. All connected devices are functioning normally (even the notebook I am typing and also the desktop after it boots!)​

Some problem or potentially worsening problem will not end well.

 

[Ralston18]

Okay. Will defer on electrical codes and practices.

= = = =

"As I said before I was able to power on the PC by blowing hot air on the motherboard with a hair drier. "

Something got warmer, expanded, and made fuller contact.

"10 minutes" - again time for something to eventually warm up and make contact.

Another factor being ambient temperature (via AC) that affects/determines warm up and cool down times.

Consider that warm up occurs, pc works, internal fans then cool, stops working.... Back and forth.

Reliability Monitor/History:

Regarding critical events: overall, how many are "stopped working" or "not properly shutdown"?

Look at Weeks as well. In both the "Days" and "Weeks" views use the small black pointers on the end of the graph to scroll in time.

And hopefully the cleaned Event Viewer logs will prove helpful.

If necessary it is possible to do some additional, filtered searching within the logs. TBD.

 

[pandre]

The PandreHardware "specs" link appears to be hosted on OneDrive (?) and opens into HTML text.

Right. It is hosted on my OneDrive.​

Which drive is "The device, \Device\Harddisk1\DR1, has a bad block." per Disk Management?

This the Seagate 1TB drive. I am sending the imgur link to the disk management​

​

In Event Viewer delete the logs to get an easier and fresher look at ongoing errors.

The error code description clearly indicates power problems.

- - - -

In Reliability History set the timeline to "Days".

It was already set to days.​

Select a date that is representative of the error codes, warning, and informational events presented. Red, yellow, blue icons.

Expand the Reliability History window so all can be seen. Take a screenshot and post the screenshot here via imgur (www.imgur.com). Use imgur for all images.

Below are "imgur" links to Reliability history of two days​

https://imgur.com/ApPOz75

View: https://imgur.com/ApPOz75
​

https://imgur.com/8hwnSDe

View: https://imgur.com/8hwnSDe
​

Air Conditioner:

In agreement with @COLGeek regarding a potential electrical problem. There should be absolutely no dependency on whether or not the AC is running.

The dependency is not on the air conditioner being on or off but on the fact that it removes humidity. As I said before I was able to power on the PC by blowing hot air on the motherboard with a hair drier.​

220 volts and 110 volts - how that is being done needs to be professionally checked.

My apartment is wired in such a way that some outlets are for 220V (specially for air conditioner). this is common here in Brazil. I mentioned that just to make sure that the PC and the air conditioner are in different circuits. Speaking about "...need to be professionally checked." I believe to be able to ensure you of this as I am an Electronic Engineer.​

Another info: I timed how long it takes after powering up the air conditioner and being able to power up the PC: it took 10 minutes for the PC to power up and start the boot process (I was constantly pressing the PC power button and it only powered on after these 10 minutes.​

And having a UPS may be adding to the problem(s). The UPS may or may not be respondingly quickly enough to cover power losses or brief voltage drops.

One of my first action (some months ago) was to bypass the UPS (which is by the of a Brazilian brand "INTELBRAS") and connected the PC directly to the power outlet, but it did not help.​

What all else is plugged into the UPS? Any other surge protectors, power strips, extension cords? You may have an electrical ground loop involved.

Nothing else is plugged on the UPS.​

The UPS's surge protection, if any, may be gone. Surge protection is measured in Joules and is cumulative. Previous power surges may have saved the protected equipment for awhile. Reached max protection. Now, little or no protection. UPS could be damaged as well.

As told above, I already connected the PC directly to the power outlet, bypassing the UPS, to no avail.​

Therefore the PC - and the disk drive in particular is now taking the hits that are physically damaging the drive and/or corrupting data.

OK. Just to avoid any doubt about the UPS, I just, once again, bypassed it and connect the PC directly to the power outlet.​

Ah! Another piece of information, I checked the voltage on the power outlet and it is at 128.8 V.​

I will have to wait till tomorrow morning to power on the PC again in the same situation.​

​

​

Very likely other system components are being stressed.


Summary: Get the electrical system inspected and checked. All circuits, outlets, and connected devices.

Some problem or potentially worsening problem will not end well.

 

[pandre]

Just to complement my answer:
You asked: "Summary: Get the electrical system inspected and checked. All circuits, outlets, and connected devices."

I inspected and checked the electrical system and all circuits, outlets and connected devices. Everything is OK.​

 

[pandre]

The PandreHardware "specs" link appears to be hosted on OneDrive (?) and opens into HTML text.

Right. It is hosted on my OneDrive.​

Which drive is "The device, \Device\Harddisk1\DR1, has a bad block." per Disk Management?

This the Seagate 1TB drive. I am sending the imgur link to the disk management​

​

In Event Viewer delete the logs to get an easier and fresher look at ongoing errors.

The error code description clearly indicates power problems.

- - - -

In Reliability History set the timeline to "Days".

It was already set to days.​

Select a date that is representative of the error codes, warning, and informational events presented. Red, yellow, blue icons.

Expand the Reliability History window so all can be seen. Take a screenshot and post the screenshot here via imgur (www.imgur.com). Use imgur for all images.

Below are "imgur" links to Reliability history of two days​

https://imgur.com/ApPOz75

View: https://imgur.com/ApPOz75
​

https://imgur.com/8hwnSDe

View: https://imgur.com/8hwnSDe
​

Air Conditioner:

In agreement with @COLGeek regarding a potential electrical problem. There should be absolutely no dependency on whether or not the AC is running.

The dependency is not on the air conditioner being on or off but on the fact that it removes humidity. As I said before I was able to power on the PC by blowing hot air on the motherboard with a hair drier.​

220 volts and 110 volts - how that is being done needs to be professionally checked.

My apartment is wired in such a way that some outlets are for 220V (specially for air conditioner). this is common here in Brazil. I mentioned that just to make sure that the PC and the air conditioner are in different circuits. Speaking about "...need to be professionally checked." I believe to be able to ensure you of this as I am an Electronic Engineer.​

Another info: I timed how long it takes after powering up the air conditioner and being able to power up the PC: it took 10 minutes for the PC to power up and start the boot process (I was constantly pressing the PC power button and it only powered on after these 10 minutes.​

And having a UPS may be adding to the problem(s). The UPS may or may not be respondingly quickly enough to cover power losses or brief voltage drops.

One of my first action (some months ago) was to bypass the UPS (which is by the of a Brazilian brand "INTELBRAS") and connected the PC directly to the power outlet, but it did not help.​

What all else is plugged into the UPS? Any other surge protectors, power strips, extension cords? You may have an electrical ground loop involved.

Nothing else is plugged on the UPS.​

The UPS's surge protection, if any, may be gone. Surge protection is measured in Joules and is cumulative. Previous power surges may have saved the protected equipment for awhile. Reached max protection. Now, little or no protection. UPS could be damaged as well.

As told above, I already connected the PC directly to the power outlet, bypassing the UPS, to no avail.​

Therefore the PC - and the disk drive in particular is now taking the hits that are physically damaging the drive and/or corrupting data.

OK. Just to avoid any doubt about the UPS, I just, once again, bypassed it and connect the PC directly to the power outlet.​

Ah! Another piece of information, I checked the voltage on the power outlet and it is at 128.8 V.​

I will have to wait till tomorrow morning to power on the PC again in the same situation.​

​

​

Very likely other system components are being stressed.


Summary: Get the electrical system inspected and checked. All circuits, outlets, and connected devices.

Some problem or potentially worsening problem will not end well.

 

[pandre]

Just to complement the information:
Therefore the PC - and the disk drive in particular is now taking the hits that are physically damaging the drive and/or corrupting data.

Just to avoid any doubt about the UPS, I just, once again, bypassed it and connect the PC directly to the power outlet.​

Ah! Another piece of information, I checked the voltage on the power outlet and it is at 128.8 V.​

I will have to wait till tomorrow morning to power on the PC again in the same situation.​

The problem remained after I bypassed the UPS​

 

[Ralston18]

128.8 volts may not necessarily be a problem. There is usually some tolerance in the actual allowed/acceptable voltages with an A/C circuit.

With some acceptance for minor peaks up to 10%. The specs may be different for your location especially with the 220 air conditioner wiring possibly being involved. Even if commonly done that does not mean that what has been done is correct or otherwise has not failed in some manner.

Then I would also keep in mind the calibration and accuracy of the test the device.

What make and model UPS? Ratings? Does the the UPS have its' own circuit breaker? Surge protection rating? Remember surge protection is cumulative and the UPS may no longer be fully and properly functional.

In any case, I will reverse to go back and to recommend having a certified electrician take a look at everything and do the applicable testing.

That 128 volts may be a hint that 220 volts is soon to follow..... Not going to end well.

No harm in getting a professional on the site to do an inspection and to make recommendations. Just to double check everything.

Arrange to demonstrate the problem(s).

Very strange situation overall and I agree that it does not make sense. I am out of ideas now.

 

[pandre]

128.8 volts may not necessarily be a problem. There is usually some tolerance in the actual allowed/acceptable voltages with an A/C circuit.

With some acceptance for minor peaks up to 10%. The specs may be different for your location especially with the 220 air conditioner wiring possibly being involved. Even if commonly done that does not mean that what has been done is correct or otherwise has not failed in some manner.

Then I would also keep in mind the calibration and accuracy of the test the device.

What make and model UPS? Ratings? Does the the UPS have its' own circuit breaker? Surge protection rating? Remember surge protection is cumulative and the UPS may no longer be fully and properly functional.

In any case, I will reverse to go back and to recommend having a certified electrician take a look at everything and do the applicable testing.

That 128 volts may be a hint that 220 volts is soon to follow..... Not going to end well.

No harm in getting a professional on the site to do an inspection and to make recommendations. Just to double check everything.

Arrange to demonstrate the problem(s).

Very strange situation overall and I agree that it does not make sense. I am out of ideas now.

Thanks for your recommendations.
128.8 volts may not necessarily be a problem.

It has never been a problem with an older PC. However, it oscillate along the time But, as measure it is always within the range [115 v , 130 v].​

With some acceptance for minor peaks up to 10%. The specs may be different for your location especially with the 220 air conditioner wiring possibly being involved. Even if commonly done that does not mean that what has been done is correct or otherwise has not failed in some manner.

Reminding. The air conditioner is powered on just for about 10 minutes (these 10 minutes is the time it takes to the PC is able to start to boot) after the boot starts I power off the air conditioner. Therefore, I believe the air conditioner is not part of the problem. I am also able to boot the PC by blowing on the motherboard with an hot air drier. That makes me als believe that the power circuit is not part of the problem.​

Then I would also keep in mind the calibration and accuracy of the test the device.

I used other test device from a friend and the measure was the same. As said above, nothing point to the power circuit to be the problem. However, I will not rule it out and will keep testing it.​

​

What make and model UPS? Ratings? Does the the UPS have its' own circuit breaker? Surge protection rating? Remember surge protection is cumulative and the UPS may no longer be fully and properly functional.

I removed the UPS and the PC is now directly connected to the power outlet. But, it was before connected to the UPS and the problem happened! ​

But just to answer your question: here is the link to the specs:

https://imgur.com/rS25uhU

View: https://imgur.com/rS25uhU
​

​

In any case, I will reverse to go back and to recommend having a certified electrician take a look at everything and do the applicable testing.

This have been suggested before and I answered that I am an Electronic Engineer and I did check and test all circuitry.​

​

That 128 volts may be a hint that 220 volts is soon to follow..... Not going to end well.

OK. Thanks. I will keep my eyes opened.​

No harm in getting a professional on the site to do an inspection and to make recommendations. Just to double check everything.

OK. Thanks.​

Arrange to demonstrate the problem(s).

How do you suggest I do this demonstration, and to whom?​

​

Very strange situation overall and I agree that it does not make sense. I am out of ideas now.

Welcome to the club!​

What I expected was someone to get ideas not related to the power circuitry. This was my first idea and besides my own action (with my electricity expertise) i checked everything I could imagine and also everything suggested. All to no avail!​

My conclusion is that the problem is not related to the power circuitry, it should be something internal to the PC. Because of that I bought a new power supply for a different brand and with even better specifications, and the problem remained.​

I also checked the electrical connections from the power supply to the motherboard (even after replacing the previous PS with a new one). This seems to rule out the PS connections to the motherboard.​

I also checked and tightened the screws on the motherboard
My conclusion is that the problem should be on the on the motherboard or on the processor. I was expecting that someone could suggest actions in these two components. ​

By the way, I already wrote earlier that the clock does not synchronizes with the internet (and, yes, I bought and changed the CMOS battery, checked its contacts and, just for the sake of it , I cleaned them).
I am asking for help on how to test the set motherboard/processor.​

​

Thanks for all suggestions and help!​

 

[Ralston18]

By "demonstrate the problem" I meant just show who ever comes to inspect or help what is happening with respect to PC and air conditioner.

And:

" I am also able to boot the PC by blowing on the motherboard with an hot air drier. '

Consider that something is loose or cracked. PC does not work until that "something" heats up, expands, and makes contact.

May well be on the motherboard, CPU, or elsewhere.

The only way to know for sure is to swap in known working components into your computer.

Install your components into some other known working computer.

Test only one item at a time. Be very methodical and careful to keep all other things the same.

Determine if the problem stays with your computer or follows a swapped component.

 

[pandre]

Thanks, Ralston18!

 

[pandre]

By "demonstrate the problem" I meant just show who ever comes to inspect or help what is happening with respect to PC and air conditioner.

And:

" I am also able to boot the PC by blowing on the motherboard with an hot air drier. '

Consider that something is loose or cracked. PC does not work until that "something" heats up, expands, and makes contact.

May well be on the motherboard, CPU, or elsewhere.

The only way to know for sure is to swap in known working components into your computer.

Install your components into some other known working computer.

Test only one item at a time. Be very methodical and careful to keep all other things the same.

Determine if the problem stays with your computer or follows a swapped component.

Just some story to enlighten the day!
Many years ago, as an Engineering Manager, in IBM Brazil Sumaré Plant, I was part of a team that reviewed the project of a mainframe that was going to be manufactured in our plant. During the manufacturing technical review meeting in IBM Endicott laboratory (upstate New York) I took issue with the fact that there was no process to electrically test the PCB that would receive the electronic logical cards . My issue, was blocking the manufacturing go ahead decision. The product program manager was forced to come down to Brazil and discuss with me an strategy to solve the problem. I will not go into details here, but with this story I wanted to point out that, testing passive PCBs is a long term problem that is not easily solved.
For me this is very similar to the problem I am facing right now.

 

[pandre]

Hi, I eventually confirmed that the problem was actually being caused by humidity. With the winter start, the humidity was lower and the PC started turning on. I then bought a hygrometer and measured the humidity. In one hotter day it failed to turn on with the humidity at 67%! I powered on the air conditioner and, after some time, I was able to turn it on. The humidity was 63%.
The next day, once again it only powered on when the humidity was at 63%.
By the way the PC was not connected to the UPS.