[SOLVED] Old computer suddenly not turning on

[Hardminder]

Hi guys. First, I know quite a few things about computers, I build my own systems and all but I'm stuck on this issue. I have an old Dell computer that I use just to watch movies in the living room, it's a very simple, 14 years old computer. For a few weeks/months I've had a startup message about the mobo backup battery being low. I ignored it but then, the computer just stopped booting. The power button is doing nothing. I replaced the battery but it did not solve the problem. I didn't change anything besides that so I don't know why it stopped working.
The network card light and the motherboard light are on. I thought it could just be something with the power switch but because it is an old mobo, it's not as simple to locate the power switch pins and try to jump it. It's not a 2 pins connector like we have on recent mobo. It's a big IDC (ribbon) connector and I don't know how to identify the two power switch pins :

I still tried to jump the 2 pins at both end but that's it. But I don't think the power switch is the problem. I don't see why it would have stopped working all of a sudden.

I know I could unplug everything and start fresh but again, it was working a week ago so why did it stopped...

I don't have any specs for this system, I don't even know what the mobo is. Any troubleshooting, ideas, suggestions are welcome. Thanks guys.

 

[drea.drechsler]

Hi guys. First, I know quite a few things about computers, I build my own systems and all but I'm stuck on this issue. I have an old Dell computer that I use just to watch movies in the living room, it's a very simple, 14 years old computer. For a few weeks/months I've had a startup message about the mobo backup battery being low. I ignored it but then, the computer just stopped booting. The power button is doing nothing. I replaced the battery but it did not solve the problem. I didn't change anything besides that so I don't know why it stopped working.
The network card light and the motherboard light are on. I thought it could just be something with the power switch but because it is an old mobo, it's not as simple to locate the power switch pins and try to jump it. It's not a 2 pins connector like we have on recent mobo. It's a big IDC (ribbon) connector and I don't know how to identify the two power switch pins :

I still tried to jump the 2 pins at both end but that's it. But I don't think the power switch is the problem. I don't see why it would have stopped working all of a sudden.

I know I could unplug everything and start fresh but again, it was working a week ago so why did it stopped...

I don't have any specs for this system, I don't even know what the mobo is. Any troubleshooting, ideas, suggestions are welcome. Thanks guys.

Being so old a prime suspect would be PSU. Dell's are generally pretty solidly built PSU's but they're also barely adequate for the system, especially if it's a consumer model. Also, capacitors still fail and resistors shift values. At some point, it just gives up.