How to repair PC mainboard

My mainboard very old(socket 370), I want to repair it but I don't know the point to begin.Please give me any possible solution.

What exactly is wrong with it?

Get rid of it! You can get something much better for very little money.

If you really want to repair mobo you need some instruments & devices (such as multimeter, soldering iron and so on)
Firstly, every repair begin from measuring of voltages (such as Vcore, Vmem etc.). Then you can made some ideas about what element on MoBo is defective and replace it on working...

And of course post here symptoms of problem (maybe MoBo beeps "memory error", maybe simply doesn't start)

I have an old server that won't start. I measure the voltage output from the power unit. Only one line has ~5V on it. Does that mean my power unit is bad or the problem might also be due to a defect in the motherboard? The "power on" switch is not directly connect to the power unit. How to "trigger"/power-on only the power unit to check the voltage?

Hi

To start ATX PSU without connecting it to motherboard you only have to short green and any black cable (GND).
https://hardwarebook.net/connector/power/atxpower.html
Cl

To start ATX PSU without connecting it to motherboard you only have to short green and any black cable (GND).

Click to expand...

note: PSU may don't start without load. One can use as load old HDD's, CD-ROM's, resistor 10-100KOm..

Thanks a lot!

To follow up, I would like to know the working principle of the power switch on the computer. With Windows XP, you can adjust the reponse of the computer when the power switch is press--to shut down or go to standby etc. When the operation system stop responding, you press and hold on the "power swtich" for a while then the computer would shut down... These behaviors indicate the CPU is involved in response to the simple action of "pressing the power switch". So my question is:

Is it possible that for certain motherboard, a bad CPU or memory module would prevent the power unit from starting up when you press the power switch?

I would like to know the answer because, the computer that I am trying to fix is an IBM server with separate power cable to a main board and a memory board (RAMBUS?) It is not easy to find a replacement power unit. And I don't remember the pin counts now. But do you have suggestion on how to test such a not-so-common power unit?

loucy

With Windows XP, you can adjust the reponse of the computer when the power switch is press--to shut down or go to standby etc.

Click to expand...

Yes, you are right. There is a mechanism for redefining power button function through ACPI. But to make this mechanism active, firstly BIOS must be started...

Is it possible that for certain motherboard, a bad CPU or memory module would prevent the power unit from starting up when you press the power switch?

Click to expand...

Yes, it is possible. For example in case of short circuit (R=0Ω). But this isn't software problem!!!

First rule - start system in most mininal configuration (PSU, MoBo, [CPU, RAM]). It can help in finding bug component.

Thanks! Root.

Before posting the questions here, I had no luck trying to started with various "minimal" configurations. I am waiting to try out the above hints. Thanks again.