5VSB signal failure

[johnyb98]

Hello.

 

I would like to make a question. If in a PSU there is a 5VSB signal failure, what are the consequences? How could a pc behave?

 

Thank you for your time!

 

John

[Arc_Jester]

There are no consequences your PC just won't turn on.

[johnyb98]

I connected the power cord as follows:

First the one edge to the PSU.

Second to the wall outlet.

But, when I plugged it to the outlet, pc turned on without my pressing the power button.

Another thing the pc makes is that either the way I described above (self power on) or with my pressing power on, after 3-4 seconds it turned off.

Could all these be because of a failure 5VSB?

[Arc_Jester]

I connected the power cord as follows:

First the one edge to the PSU.

Second to the wall outlet.

But, when I plugged it to the outlet, pc turned on without my pressing the power button.

Another thing the pc makes is that either the way I described above (self power on) or with my pressing power on, after 3-4 seconds it turned off.

Could all these be because of a failure 5VSB?

I don't think this is because of an 5VSB failure if that was the case to PC wouldn't turn on at all. Try replacing the PSU, if the PC works after the replacement you will need to get a new PSU.

[johnyb98]

The case continues as follows...

 

I removed completely PSU from the case. So, all power cables are removed from motherboard, and every internal drive/fan. I tested the PSU with a tester, and it beeped, showng that something is wrong with the 5VSB rail. I am not sure if this indication-beep on the tester monitor was indeed refered to 5VSB or another problem of the PSU. But, anyway, the fact that the tester beeped all the time, proves that the PSU has problem, and needs to be replaced.

 

After the PSU removal from the case, I also removed the two cards (AGP VGA and a PCI modem), and one DDR1 1GB RAM module. I reseated them very well (after cleaning the little dust each one of them had on it).

 

Also, I reseated the CR2032 mobo battery I had removed in order to measure its volts with the multimeter. Multimeter showed an oscillation between 2.89V - 2.90V. I mention battery because, before removing PSU and battery, on some bootings, boot process stopped with error message

 

"CMOS checksum error - Defaults loaded

Press F1 to continue, Del to enter setup"

 

So, now, placing again back PSU and battery (even with 2.9V), I have made about 10 bootings, and no CMOS error message at the beginning, and PC booted only with my pressing the power on button. Either plugging the power cord to the wall socket or connecting the pc to a UPS, in both cases pc waits for my hand to press the power on.

 

I do not know what to think about all this. The PSU is faulty with the tester help, and battery has little volts for PC level staff (<=2.9V I think it needs to be replaced).

So, now, after removing PSU and battery, cards, RAM module, and reseating them back, everyting seems to work fine. Of course, I have made only about 10 bootings, but I do not know in which time-to-time boot wrong boot or CMOS error message may appear.

 

What is your opinion/help about all that?

[Arc_Jester]

I'm not quite sure what to make of this situation, you should probably replace the PSU with a new one since the tester reported an error but if it works fine now, then it's up to you if you want to replace it. Report back if it decides to misbehave again.

[johnyb98]

My final decision, for three reasons of a. your help, b. a since 2005 pc without any PSU replacement and c. PSU tester results, is to replace PSU unit. I do agree with you that if after the replacement I will have again such problems, I will come back to the topic.

 

For now, I would like to thank all for your help !!

[Arc_Jester]

My final decision, for three reasons of a. your help, b. a since 2005 pc without any PSU replacement and c. PSU tester results, is to replace PSU unit. I do agree with you that if after the replacement I will have again such problems, I will come back to the topic.

 

For now, I would like to thank all for your help !!

No prob