Question Old pc startup problems ( post beeps, sometimes goes through )

[Kolagner]

Hello,

got my hands on an old desktop pc with a celeron 400MHz and chaintech 6btm mobo.

When I first powered it, all fans go online ( cpu and psu ), but the PC would make the POST beeps, a continuous siren ( long-short-repeat ). I've checked the capacitors, and they seem to be fine. I removed the bios battery to clear the settings, starting up without one atm. Afterwards the PC for some reason managed to get past the post, just once-twice and then shut down completely.

I assumed might be the psu, so I replaced it with a different one. Now the pc starts up, goes into POST beep ( siren ) for 2 seconds, then it stops and continues to start up giving one startup beep, and proceeds to the bios menu. I can't continue yet because I do not have a ps2 keyboard and it asks me to press F1 to continue. While I'm looking for a keyboard, what else I can do to investigate the source of the problem. I'm not sure if the cpu is busted, the mobo or some of the wiring. Everything looks intact visually, I removed most of the dust. The few times it makes to startup it has Memory 163840K OK, so I'm thinking ram might not be the problem.

Little experience reviving old dead PCs, want to figure out if this one can live, or if not what is the issue so I can still salvage the working bits.

 

[Darkbreeze]

You're seeing this, almost certainly, for two reasons.

One, there is no CMOS battery installed, and the one that was in it is pretty certainly no good anymore if this has been sitting a while or just given it's age. This will generally cause it to go straight to the BIOS. Get a new CR2032 battery and install it.

Two, the system is not seeing a keyboard and the BIOS in it's default configuration (Which is where it will be with no CMOS battery installed) will generally beep and halt when no keyboard is detected.

 

[CelicaGT]

Did you inspect the caps visually? They do not always fail in such a manner that they bulge or leak. You can try and search the beep codes for that mobo online while you wait for a keyboard. Most of these machines had a halt on no keyboard and a halt on FDD failed or missing. Both can be disabled in BIOS but as you've reset defaults they are both likely on so you might only need to save and exit the BIOS once to continue. You'll need that battery replaced too. Be warned it's been a minute since I've worked on these so I'm rusty as all hell.

 

[Darkbreeze]

you might only need to save and exit the BIOS once to continue.

Without a good CMOS battery installed this will do absolutely no good since it won't be able to retain the settings.

 

[Kolagner]

You're seeing this, almost certainly, for two reasons.

One, there is no CMOS battery installed, and the one that was in it is pretty certainly no good anymore if this has been sitting a while or just given it's age. This will generally cause it to go straight to the BIOS. Get a new CR2032 battery and install it.

Two, the system is not seeing a keyboard and the BIOS in it's default configuration (Which is where it will be with no CMOS battery installed) will generally beep and halt when no keyboard is detected.

Yeah, im working on finding a ps2 keyboard. Will get the battery tomorrow. I still do not think these 2 are related to the post problems and the beeps. Atm it sometimes goes into siren post, or it sirens for 2 secs and passes.

 

[Darkbreeze]

There is zero chance of knowing whether it is or is not related until you resolve those two issues. And yes, having no CMOS battery or one with low voltage can absolutely cause those, and many other symptoms. Some systems simply won't POST at ALL with no CMOS battery installed or a dead one. And pretty much ALL systems will halt or go straight to BIOS if no keyboard, whether PS2 or USB, is detected. With a properly functioning CMOS battery installed you SHOULD be able to enable the system for use with a USB keyboard but in order for the setting to be retained you MUST have a good battery installed. Per your manual:

If you want to use a USB keyboard, you must enable the
USB keyboard support function in BIOS's Integrated
Peripherals menu (See Section 3-7).

And for the record, your manual is located here: https://ia600700.us.archive.org/33/items/6BTMManual/6BTM-Manual.pdf

 

[CelicaGT]

Without a good CMOS battery installed this will do absolutely no good since it won't be able to retain the settings.

Yes, that's in my comment too, towards the end. Could have been more prominent I guess but I'm doing technical training at home and splitting my attention lol

 

[Kolagner]

There is zero chance of knowing whether it is or is not related until you resolve those two issues. And yes, having no CMOS battery or one with low voltage can absolutely cause those, and many other symptoms. Some systems simply won't POST at ALL with no CMOS battery installed or a dead one. And pretty much ALL systems will halt or go straight to BIOS if no keyboard, whether PS2 or USB, is detected. With a properly functioning CMOS battery installed you SHOULD be able to enable the system for use with a USB keyboard but in order for the setting to be retained you MUST have a good battery installed. Per your manual:




And for the record, your manual is located here: https://ia600700.us.archive.org/33/items/6BTMManual/6BTM-Manual.pdf

Yes, that's in my comment too, towards the end. Could have been more prominent I guess but I'm doing technical training at home and splitting my attention lol

Well...

1) I have tried another battery from a different PC, the CMOS checksum error is still there, so unless this one is dead as well ( possible ), there is something with the bios.

2) The usb connection for the keyboard does not work. I have connected my usb keyboard to the usb jacks on the mobo ( both of them ), no response. Neither the backlight nor the keys, still error kb undetected. I have an usb-ps2 adapter which I tried, this one gives lights but the keyboard still doesnt work. I read that these adapters might not work with all keyboards, so I assumed that.

Tomorrow I will get another battery and try again. I looked into the manual, and it states " If you want to use a USB keyboard, you must enable the USB keyboard support function in BIOS's Integrated Peripherals menu (See Section 3-7). ". Might be this, but there is also "When using a USB keyboard this function is automatically Enabled during bootup regardless of its setting in BIOS. " =/

 

[Darkbreeze]

Well, I agree it's kind of a conundrum since you really need to set the option in the BIOS in order to not need to use a PS2 keyboard and allow a USB keyboard to work, but you need a working keyboard to change the BIOS setting. So yeah, first order of business is probably finding a PS2 keyboard.

 

[Paperdoc]

A few hints to help.

1. Actually, electrically a PS/2 keyboard and a simple plain USB keyboard are identical - only the connectors are different. So, you can get a very simple adapter (try a used or brand-new computer shop) that allows you to plug into one end your USB keyboard, and the other end plugs into the mobo's rear PS/2 socket. Simple and cheaper than finding an old PS/2 keyboard.

2. The NORMAL boot sequence is that all your fans start up at full speed right at the beginning, and then the POST process starts. IF that process completes cleanly, you will get ONE fairly short beep to signal success, and the fan speeds will go slower since the system is cold. If there is a problem in the POST, that is what you will generate other beep codes during the POST to signal particular errors. In a brief search I could not find a list of the error codes for that mobo.

3. There are two items you list that VERY likely will cause beep errors codes: lack of a keyboard (will be fixed when you get one connected), and a failed (or non-existent) floppy disk drive. MAYBE also the missing CMOS battery - that also will be fixed when you get one.

4. In its current state, the BIOS POST process detects there is no battery-maintained configuration data in BIOS, so it loads the factory defaults. Those settings likely try to use the floppy drive FIRST to boot from, and then may try the HDD if the floppy does not work. But maybe it does not even try a second boot device. Once you have a keyboard AND a battery to maintain saved configuration data, you can use BIOS Setup to change the boot device settings.

5. In its current state the system probably cannot find a boot device with a valid OS to load. So it will default by going into BIOS Setup every time. Once you have the item above sorted out, you can work on where to find a bootable device with an OS installed so it can get running.

6. You can download a free Manual from this web page

https://theretroweb.com/motherboards/s/chaintech-ct-6btm#downloads

Click on the User Manual item near the bottom. Note also it has a few BIOS images you could download to install AFTER you have your system working and know HOW to update the BIOS. In that manual on p. 45 it says the details on BIOS updating are in a .pdf file on the CD_ROM disk that came with the mobo. Any chance you have that? If not, you will have to search IF you want to update., ALSO, such a process usually meant using the floppy drive for the old and new BIOS files, so you'd need that working to do this.

7. For mobos of this era, you typically had to enter the parameters of the HDD you have installed - see the manual p. 22 - 24. The info for that ought to be on a label on the HDD unit. Alternatively, some HDD's were able to provide that info to a BIOS utility you can use - see manual p. 43 - to get that info for you. One small warning about that though. On SOME systems (this is NOT common), a prior user MIGHT have set the HDD parameters to something NOT what the HDD itself was intend for, so the info from the label and from the auto-detect utility MIGHT not work. That makes things hard! What is more common is that the utility might show you several POSSIBLE sets of settings, and you need to know what the HDD LABEL says to pick the correct one.

 

[Darkbreeze]

On newer motherboards that still have PS2 ports, those passive adapters will usually work. But there are a lot of USB keyboards that won't work with PS2 adapters. They might be electrically the same but they are definitely not all signalling the same. I've had MANY, MANY experiences with keyboards that were USB and simply would not work with a passive PS2 adapter. It's worth trying if you have an adapter already but I can't see rolling the dice on the idea that it's going to work with a motherboard that old and a passive adapter when those adapters cost five or six bucks and that's five or six bucks that could go towards the purchase of a 10-20 dollar PS2 keyboard that there is no doubt at all about whether it will work or not.

Paperdoc knows his business, but on this one I'm going to have to disagree. It's a crapshoot when it comes to whether a given keyboard is going to work with a passive USB to PS2 adapter or not IMO.

 

[Kolagner]

A few hints to help.

1. Actually, electrically a PS/2 keyboard and a simple plain USB keyboard are identical - only the connectors are different. So, you can get a very simple adapter (try a used or brand-new computer shop) that allows you to plug into one end your USB keyboard, and the other end plugs into the mobo's rear PS/2 socket. Simple and cheaper than finding an old PS/2 keyboard.

2. The NORMAL boot sequence is that all your fans start up at full speed right at the beginning, and then the POST process starts. IF that process completes cleanly, you will get ONE fairly short beep to signal success, and the fan speeds will go slower since the system is cold. If there is a problem in the POST, that is what you will generate other beep codes during the POST to signal particular errors. In a brief search I could not find a list of the error codes for that mobo.

3. There are two items you list that VERY likely will cause beep errors codes: lack of a keyboard (will be fixed when you get one connected), and a failed (or non-existent) floppy disk drive. MAYBE also the missing CMOS battery - that also will be fixed when you get one.

4. In its current state, the BIOS POST process detects there is no battery-maintained configuration data in BIOS, so it loads the factory defaults. Those settings likely try to use the floppy drive FIRST to boot from, and then may try the HDD if the floppy does not work. But maybe it does not even try a second boot device. Once you have a keyboard AND a battery to maintain saved configuration data, you can use BIOS Setup to change the boot device settings.

5. In its current state the system probably cannot find a boot device with a valid OS to load. So it will default by going into BIOS Setup every time. Once you have the item above sorted out, you can work on where to find a bootable device with an OS installed so it can get running.

6. You can download a free Manual from this web page

https://theretroweb.com/motherboards/s/chaintech-ct-6btm#downloads

Click on the User Manual item near the bottom. Note also it has a few BIOS images you could download to install AFTER you have your system working and know HOW to update the BIOS. In that manual on p. 45 it says the details on BIOS updating are in a .pdf file on the CD_ROM disk that came with the mobo. Any chance you have that? If not, you will have to search IF you want to update., ALSO, such a process usually meant using the floppy drive for the old and new BIOS files, so you'd need that working to do this.

7. For mobos of this era, you typically had to enter the parameters of the HDD you have installed - see the manual p. 22 - 24. The info for that ought to be on a label on the HDD unit. Alternatively, some HDD's were able to provide that info to a BIOS utility you can use - see manual p. 43 - to get that info for you. One small warning about that though. On SOME systems (this is NOT common), a prior user MIGHT have set the HDD parameters to something NOT what the HDD itself was intend for, so the info from the label and from the auto-detect utility MIGHT not work. That makes things hard! What is more common is that the utility might show you several POSSIBLE sets of settings, and you need to know what the HDD LABEL says to pick the correct one.

Hey,
I wrote up there that I have tried a usb-ps2 adapter and it didnt work. Used 2 keyboards, the backlights were on, but still undetected. Thanks for the extra info though, Im still working on finding a ps2 keyboard which is apparently not easy ( no local sellers, new or used ). The startup beep is the semi-siren which gets cut off, then it proceeds and gives a short beep and goes into the startup menu.
Until I get a ps2 keyboard im stuck, will update once I get it

 

[Paperdoc]

Computer shops and used parts places are obvious places to look. Might try also computer REPAIR firms that may have old parts. ALSO look for a place near you thyat accepts for disposal and recycling old electrical devices - they may have a junk keyboard someone discarded. Might even try the IT people at a university, college or school board in case they have old junk.

 

[Darkbreeze]

I see PS2 keyboards all the time at second hand places like the ARC, Goodwill, Salvation army, other local second hand shops and flea market stalls, plus you can often find them on Ebay, Craigslist and of course there are plenty on Amazon and other online retailers.

 

[Kolagner]

Computer shops and used parts places are obvious places to look. Might try also computer REPAIR firms that may have old parts. ALSO look for a place near you thyat accepts for disposal and recycling old electrical devices - they may have a junk keyboard someone discarded. Might even try the IT people at a university, college or school board in case they have old junk.

Update:
I've finally found a ps2 keyboard, I also fixed the floppy error by poking around with the drive's power cables, cant check if its working at least error is not there.

The PC BOOTS, I even managed to get into the OS, which is Windows XP ( surpsisingly ). Yeah, it lags and is very slow, the cpu fan is very loud and noisy, but the PC starts.

The problem remains with the CMOS checksum error. I have replaced the battery with a completely NEW one, error is still there however. I'm thinking if maybe I screwed up the battery slot and it doesnt make contact, otherwise not sure what is the problem.

 

[Paperdoc]

Now that you've replaced the battery, next step. Go into BIOS Setup to find the Exit Menu. ONE of the options there often is to Restore Factory Default Settings. Choose that. This step completely replaces ALL user settings in the BIOS EEPROM with VALID data. So IF you know that some settings are RIGHT - like, for example, the settings for the HDD - write them down FIRST. AFTER you have done the Restore, go through Setup and enter the things you know SHOULD be changed (e.g those HDD settings, and which drive to boot from), THEN go though Exit Menu again and Save and Exit. Hopefully this will correct whatever error was in the stored data and eliminate the Checksum Error. Then you can proceed with other tweaks.

 

[Darkbreeze]

Now that you've replaced the battery, next step. Go into BIOS Setup to find the Exit Menu. ONE of the options there often is to Restore Factory Default Settings. Choose that. This step completely replaces ALL user settings in the BIOS EEPROM with VALID data. So IF you know that some settings are RIGHT - like, for example, the settings for the HDD - write them down FIRST. AFTER you have done the Restore, go through Setup and enter the things you know SHOULD be changed (e.g those HDD settings, and which drive to boot from), THEN go though Exit Menu again and Save and Exit. Hopefully this will correct whatever error was in the stored data and eliminate the Checksum Error. Then you can proceed with other tweaks.

This.

Congrats. It's progress at least.

 

[Kolagner]

This.

Congrats. It's progress at least.

Welp, turned it on a few days ago to poke around the bios, and the PC didn't start. Pulling out the PSU, removing bios battery, now I get the beeping music again.

Since its the second PSU, It feels like its the mobo?

Doesnt explain how I was able to log into the windows and sit in it before, idk =/

 

[Kolagner]

Now that you've replaced the battery, next step. Go into BIOS Setup to find the Exit Menu. ONE of the options there often is to Restore Factory Default Settings. Choose that. This step completely replaces ALL user settings in the BIOS EEPROM with VALID data. So IF you know that some settings are RIGHT - like, for example, the settings for the HDD - write them down FIRST. AFTER you have done the Restore, go through Setup and enter the things you know SHOULD be changed (e.g those HDD settings, and which drive to boot from), THEN go though Exit Menu again and Save and Exit. Hopefully this will correct whatever error was in the stored data and eliminate the Checksum Error. Then you can proceed with other tweaks.

Well, after it stopped turning on, today it once again turned on after beeps ( after removing and putting back cmos ). I did what you wrote, and there was no checksum error anymore, it booted up normally and I was able to use it for around 30 mins.

Still, the fact that it does not boot consistently bothers me. Weird thing was that PC was starting immidiately after plugging in the psu, without pushing the switch.
I'm either at second psu failure or some motherboard problem, but the PC does work when it starts so can it really be the mobo? =/

 

[Paperdoc]

If the computer turns on immediately when you plug its power cord into a wall outlet, then the case On / Off switch is faulty. I assume this is a relatively newer PSU design so that the front case switch is a simple pushbutton that springs back out, just like a doorbell button. In that system the button switch on the front IS a normally-open temporary contact device that merely shorts together two contacts inside the switch. The leads from it are connected to two pins of a Front Panel header on the mobo. A short across those two pins is the signal to the MOBO to turn on. To check, trace those two wires to that header and identify them. Polarity does not matter. You can DISconnect the two wires from those pins with your system unplugged. Now plug in. If the system starts up immediately the mobo has a problem. If not, the switch may bave a problem. Use a small screwdriver to temporarily short those two pins, and the mobo should turn on and boot. Shut down without unplugging, and it should shut down and stay off. If all that works, then re-connect the two wires from the front switch to those header pins. If the system boots right away, you know that the switch button itself has a problem. If the problem has disappeared, you have a puzzle!

If it appears the switch itself is shorted out and causes instant start-ups, that can cause another issue. Once the system is running, holding that button in (a sustained short) for over 5 sec. normally causes the system (mobo) to shut down. BUT once that happens, it is still shorted and so the system will start up again! And repeat!

If that switch is permanently shorted out inside, you have two choices. One, of course, is to replace that case front button with another pushbutton switch of the same type. The other is to re-purpose an existing pushbutton to replace the On / Off button. The front case RESET button is the SAME type, and its two wires also connect to a different set of pins on that mobo Front Panel header. You can simply disconnect the On / Off button's wires from their normal header pins and then connect to those pins instead the two wires from the Reset button. Now you have no reset button, but the one that SAYS Reset on the front of your case is now the power button.

 

[Darkbreeze]

Power off, unplug the PSU from itself or the wall, unplug the wiring to the case switch that powers it on, then plug the PSU back in and switch it back on using the switch on the PSU. If it does not power on immediately now then Paperdoc is correct and it pretty much has to be the switch. If it DOES power on immediately regardless that the front case power switch isn't connected then it pretty much has to be a motherboard problem. And like he says, if there is a reset AND a power switch, make sure they are both disconnected when you try testing it.