Old PC Needs Fixing

[BristolBrick]

I have an old PC (mid/late 90s) I want to get working. Found it in my grandpa's attic. When turned on, power and reset lights come on at the front. (Odd, because HDD works after 20 years, no HDD light) It sends no input to the screen.

Warning! Terrible cable management!

AT socket.

Yes, I drew the face on that cable with paint. I was bored.

[ShaunOfNintendo]

When you sad "It sends no input to the screen", do you mean that the standard text that appears when a PC boots up isn't there?

[Flavortown2k16]

Ill take wild guess and say its mobo thats causing this

[BristolBrick]

25 minutes ago, ShaunOfNintendo said:

When you sad "It sends no input to the screen", do you mean that the standard text that appears when a PC boots up isn't there?

Yes. Not even black. My moniter has a light on the ront that flickers when not getting signal, but is solid when receiving it. It is 1600x1200, but that couldn't stop a PC booting could it?

[ShaunOfNintendo]

1 hour ago, BristolBrick said:

Yes. Not even black. My moniter has a light on the ront that flickers when not getting signal, but is solid when receiving it. It is 1600x1200, but that couldn't stop a PC booting could it?

Like @Flavortown2k16 said. The motherboard would most likely be causing that. The components could have simply degraded overtime. I don't want to say something like "X is broken" because there could be any number of reasons for something like that to happen.

 

Could you post a picture of what the monitor looks like when you try to boot it up?

[Shingouki]

Can you disassemble it, clean everything, and post some photos of the components? Also i'd suggest you to test the PSU. It's the first thing to check, then reassemble it.

Just wondering: are there some bulged capacitors?

[BristolBrick]

13 minutes ago, ShaunOfNintendo said:

Like @Flavortown2k16 said. The motherboard would most likely be causing that. The components could have simply degraded overtime. I don't want to say something like "X is broken" because there could be any number of reasons for something like that to happen.

 

Could you post a picture of what the monitor looks like when you try to boot it up?

Moniter is black. Plain and simple. It recons the computer is turned off.

[BristolBrick]

CPU is AMD Am486 DX4-100

[BristolBrick]

How can I test if it's CPU and not motherboard with no other test PCs?

[Shingouki]

If you're referring to me, i said PSU, the power supply, not the CPU. In all the computer i've repaired, only once it was the cpu, so it's the last thing i test.

[BristolBrick]

5 hours ago, Shingouki said:

If you're referring to me, i said PSU, the power supply, not the CPU. In all the computer i've repaired, only once it was the cpu, so it's the last thing i test.

Oh, PSU tested and is ok. How do I know it's the mobo and not the CPU at fault?

[Shingouki]

So, PSU, is giving all the correct voltages even under load. Great. First thing to remove.
If you don't have another cpu, the best way to see if a motherboard is working is testing the pieces first with voltmeter and then with oscilloscope, but you'll need the service manual of the motherboard.

Obviously all these tests are useless if capacitors are bulged, since if capacitors are bulged (on motherboard or vga) you already found what problem you have

Does it post? Does it give you error if you try to boot with no VGA card or no RAM? Is everything plugged in correctly?

[BristolBrick]

Took out RAM, did no errors.

[Shingouki]

If you take all the ram out, and it does not start making beeps after you turn it on, very likely it's the motherboard. disconnect everything from the motherboard, except buzzer, power supply and CPU and if it does not beep, it's surely the motherboard. If it beeps, start connecting one piece at time, and try again every time, if after connecting that piece it does not beep but doesn't do anything anyway, you found the broken piece