Sounds very likely that your PSU has gone lame on you.
Here is the situation that I need to resolve:
System comprised of Fic va503+ mainboard with Amd-k6-2-500 cpu, 128M ram, Ati video card, atx power supply, sound card and modem had been running without a problem for more than two years.
One day lately when working on it - the pc stopped abruptly, screen blanked out - only the power supply fan's humming sound could be heard, hd and cpu fan became silent. Tried to restart the pc with reset button in vain, indicator led-s were up, power supply fan also ran, monitor was on but screen was blank and there was no sign of booting up. Then opened the box, pressed the power button - the cpu fan restarted after some hesitation, with no sign of booting up, again.
I have my plan how to diagnose it systematically, however I would be interested to hear if someone had a comparable experience and was able to get it resolved with a minimum of cost.
I thought about it - voltages on PS connector terminals are in spec.
What do you think?
Do you run a surge protector on your system. If you had a surge, it could have fried RAM, CPU or other things. The sudden nature of the change suggests something like that.
You might want to run a minimal boot and see what happens. This would be no drives and only one stick of RAM. It would be good to remove cards like modems and sound, but leave the video. See if you get POST and if you don't, post a reply here.
The system had always been powered trough a surge protected strip.
Ok, I am going to try a boot up with a barebone setup.
When disconnecting fd, hd and cd drives - besides data cables should I detach their ps cables as well?
Yes, part of what you are doing is checking to see if the power supply may be part of the problem and leaving the power connected will confound that.
Also, if you are using a good power strip for surge protection (the kind that come with a guarantee to replace fried equipment) you should be fine. If you are using a basic one, it may not really protect against surges at all.
Ok, tried to boot it up in minimal configuration - with a stick of ram, video card and keyboard only - ps and cpu fans spin up - and again nothing happens - screen remains blank. Will try it again with another video card.
Next it may be the cpu, ram, bios chip, anything else on mb?
Could it be that the mb battery died and bios chip got disabled?
When you say nothing, you mean no beep or anything?? Is your case speaker hooked up? If you got no beep and the case speaker is hooked up, you probably have a bad CPU, motherboard, power supply or (remotely) fried BIOS. A dead battery would mean that any changes you made to the BIOS would be lost and your clock would need to be reset, but it shouldn't cause a complete BIOS failure. If the BIOS were actually destroyed in some way, it would, of course, cause failure because there wouldn't be a BIOS, but that is very unlikely.
Then first thing I would try is another power supply if you can get your hands on one. The reasons for this is that it is the easiest to remove and replace and it is likely to be cheaper than a new mobo and/or CPU. The only way I know to test the mobo and CPU is to swap them out with a compatible and known good system.
You could also try the barebones boot out of the case to rule out the possibility of a short. Keep the power switch and speaker connected so you can turn it on and hear if you get a POST beep. Put it on a nonconductive surface (like a piece of cardboard) to test. If no go, go back to testing power, CPU and mobo.
Yes, I forgot to say that there was no beep either - speaker is connected.
Even before this recent crash - I noticed the following:
When the system was being turned on I heard something strange: after depressing the power switch the cpu fan sounded spinning up then down for may be a second or two then up (raising in pitch gradually) again and stabilized by the time the op system was up. It was interesting that I could not reproduce this with the open box.
Since I kept the system powered on for weeks or months and it worked fine I just disregarded the issue. Could it have been a sign of something that resulted in the eventual total crash?
Anyway, it is obvious now that I have to start replacing the components one by one.
If your CPU fan was failing and letting the CPU overheat, it may have burned it out. I would try 2 things. First I would replace the CPU fan and try again after making sure it is plugged into the mobo. If it still doesn't work, I would try a compatible CPU and see if it works.
Will POST start with no ram on mb?
On many boards, you will get a POST error beep without RAM onboard, but you would have to check your BIOS to see if that is true of yours.
Powered up the mb (with video card and ram module) out of the box -
and voila - post screen (confirmed cpu and ram) showed up. Repeated it several times with success, then added another ram module, post (with new ram) was still ok, then reseated the mb into box again, positively checked the post a few times - hower once only one ram module was recognized, last post was fine. Reconnected the drives and ... at power up NO post again. Disconnected everything, still no post. Will also take the mb out of the box again and see what will happen.
It looks there is some intermittancy in the system.
Is this mb a toast?
It sounds like you have a short in there somewhere and you will need to track it down. The mobo is probably ok, but repeated shorting could damage it. A short is usually going to be due to pieces of metal touching that shouldn't be. One prime possibility it with the standoffs that connect the motherboard to the case, but it could also be something that moves a little bit with setting things up, which would account for it being intermittant. The only way I know to find it is with careful inspection along with tral and error.
Repeated powering up the system a few more times while adding components step by step and arrived to a conclusion that the psu could well be the source of intermittency.
Replaced it with a brand new psu from a reputed source and the system has been running perfectly since then.
In the meantime upgraded the system somewhat by doubling ram and replacing the cpu with a faster one.
Thanks for help to all on the forum who replied.
Its good to hear you got it fixed...
Thanks for checking back in to let us know what happened, it may help in solving the next similar problem that comes along...
I had the same exact problem last week. Just troubleshot and fixed my parents yesturday, PSU went bad also. Where were you during the northeast power outage that effected NYC?
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