[SOLVED] PSU and paperclip test

Jun 26, 2019
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Hi, my desktop PC stopped working today. It was left on for some time and when I came back to it, it was off I can't make it run at all (not even a fan starts turning)

I did the paperclip test to see if PSU is to blame and nothing happened. However when I plug the cable to the MB, the onboard led lights green to indicate existing power supply.

How should I interpret these conflicting messages?

Thanks.
 
Solution
Overall, it could indeed have been a fault in the PSU.

Unplug the computer and open the case. Use a bright flashlight to inspect in and around the PSU. Look for blown components, black/brown streaks, carbon spots, anything melted.

Sniff: you may be able to detect some lingering odor of burning,etc..

PSU's are not repairable so do not open up the PSU itself.

And with limited troubleshooting about all that can be done is to get another known working PSU to swap in.

Which may likewise prove difficult... No guarantees either that the PSU is/was the culprit.

Ralston18

Titan
Moderator
My thought is that the PSU has failed.

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

Include PSU: make, model, wattage, age, condition.

Some immediate things you can do:

Check that all internal cables, cards, RAM, jumpers, etc. are fully and firmly in place?

If necessary use canned air to blow out dust, debris, dead bugs, paper scraps, etc..

------

The paper clip test is only a basic test.

Do you have a multimeter and know how to use it. Or have a knowledgeable family member or friend who does?

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Still not a full test per se as the PSU is not under load. However any voltages out of spec indicate problems.
 
Jun 26, 2019
11
0
10
My thought is that the PSU has failed.

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

Include PSU: make, model, wattage, age, condition.

Some immediate things you can do:

Check that all internal cables, cards, RAM, jumpers, etc. are fully and firmly in place?

If necessary use canned air to blow out dust, debris, dead bugs, paper scraps, etc..

------

The paper clip test is only a basic test.

Do you have a multimeter and know how to use it. Or have a knowledgeable family member or friend who does?

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Still not a full test per se as the PSU is not under load. However any voltages out of spec indicate problems.
First of all I have no multimeter and I can't really get someone to help me due to quarantine conditions.

PSU: Cooler Master 650W, about year old. I bought new one when I updated to better GPU

Unfortunately I don't remember much about the exact hardware specification and can't check, since the PC won't run.

I know the CPU is one of the early i5 Skylake
MB is Asus H170M-plus
GPU is RTX 2070 by Gigabyte
16gb RAM in two sticks, also upgraded about a year ago
One SSD drive
One HDD drive
I don't really use other hardware beyond mouse, keyboard, headphones and occasionally cell phone to charge it.
 
Last edited:

Ralston18

Titan
Moderator
References:

Motherboard:

https://www.asus.com/sg/Motherboards/H170M-PLUS/specifications/

Motherboard User Manual (verify):

https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/H170M-PLUS/E10763_H170M-PLUS_UM_WEB.pdf

As I understand the specs, the recommended PSU wattage for your GPU is 650 watts.

Do you do heavy gaming or use graphics intense applications?

Overall the PC's power demands may have accelerated the PSU reaching its' designed EOL (End of Life).

Check connections and clean as suggested.

Try pulling the GPU and use the motherboard's graphics port for video.

However, if nothing can be made to happen then the PSU is the likely culprit.
 
Jun 26, 2019
11
0
10
References:

Motherboard:

https://www.asus.com/sg/Motherboards/H170M-PLUS/specifications/

Motherboard User Manual (verify):

https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/H170M-PLUS/E10763_H170M-PLUS_UM_WEB.pdf

As I understand the specs, the recommended PSU wattage for your GPU is 650 watts.

Do you do heavy gaming or use graphics intense applications?

Overall the PC's power demands may have accelerated the PSU reaching its' designed EOL (End of Life).

Check connections and clean as suggested.

Try pulling the GPU and use the motherboard's graphics port for video.

However, if nothing can be made to happen then the PSU is the likely culprit.
Thanks, that is the correct MB

I hope that getting recommended PSU wouldn't shorten life span to one year even with heavy usage (which isn't really my case).

Anyway, I will try disconnected the power cables from GPU and run it again like this.
Cleaning isn't necessary, I did thorough cleaning including new cooling paste on CPU a year ago (I regularly monitor CPU temperatures and I know I did a good job there)

There is perhaps one more thing. When I installed the new PSU a year ago, I wasn't able to push the 24 pin connector all the way in. No matter what I did, there was about 1 mm gap I couldn't close, but everything ran fine. I had no crashes or anything that would indicate power supply problems and I tried to push it in again today.
 

Ralston18

Titan
Moderator
Total up the recommended wattages for all installed components. If a wattage range is provided use the high end value.

For GPU use the recommended PSU wattage.

Once wattages are all totaled add 25% more. How close is that final total to your PSU's wattage?

There are also online calculators to help with making such calculations. Try two or three of them to determine if there is a consensus value for the wattage requirement.
 
Jun 26, 2019
11
0
10
Total up the recommended wattages for all installed components. If a wattage range is provided use the high end value.

For GPU use the recommended PSU wattage.

Once wattages are all totaled add 25% more. How close is that final total to your PSU's wattage?

There are also online calculators to help with making such calculations. Try two or three of them to determine if there is a consensus value for the wattage requirement.
Looking at NVidia site, they actually recommend 550W and not 650W (I knew I counted with safety margin there)
I tried two calculators and both claim that even 500W would be more than enough for my needs, so if PSU failed, it must have been some hardware fault.
 

Ralston18

Titan
Moderator
Overall, it could indeed have been a fault in the PSU.

Unplug the computer and open the case. Use a bright flashlight to inspect in and around the PSU. Look for blown components, black/brown streaks, carbon spots, anything melted.

Sniff: you may be able to detect some lingering odor of burning,etc..

PSU's are not repairable so do not open up the PSU itself.

And with limited troubleshooting about all that can be done is to get another known working PSU to swap in.

Which may likewise prove difficult... No guarantees either that the PSU is/was the culprit.
 
Solution
Jun 26, 2019
11
0
10
Overall, it could indeed have been a fault in the PSU.

Unplug the computer and open the case. Use a bright flashlight to inspect in and around the PSU. Look for blown components, black/brown streaks, carbon spots, anything melted.

Sniff: you may be able to detect some lingering odor of burning,etc..

PSU's are not repairable so do not open up the PSU itself.

And with limited troubleshooting about all that can be done is to get another known working PSU to swap in.

Which may likewise prove difficult... No guarantees either that the PSU is/was the culprit.
I have already ordered a new one, it should be available tomorrow.
I don't want to tinker with the current one too much, because it is still under warranty, so if it really is faulty, I should get my money back.

Replacing PSU is not a problem, I have done it last year, just a few screws and cables. The biggest hassle is to remove the GPU first, because one of the cables must go under it :)

Anyway thanks for the help. Hopefully it really is PSU. If it is anything more complicated like motherboard or CPU, I don't think it is worth getting replacement part and I would rather upgrade and that's pretty costly.