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I have a PC that has been running fine, except with non-functioning front USB ports. Below images explain why. My question is: Can I continue running the PC like this (provided that it's been running like this for weeks) or is there a reason to change the motherboard immediately? Would prefer to do a proper upgrade at a later stage rather, if possible.
Guit4eva
Posted 2018-10-09T14:35:01.350
Reputation: 193
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Looks like you had a short in a power supply line near that header, which overheated things considerably. Eventually it got so hot that things separated enough that there was no longer a short. But something must have been limiting the current somewhat - otherwise the power supply would have shut down.
My concern would be that there's no reason (given that things there are just not mechanically stable) that ordinary thermal cycling couldn't cause things to move around enough that it wouldn't short out again, and maybe do more damage.
In other words, I'd replace it as soon as possible.
Jamie Hanrahan
Posted 2018-10-09T14:35:01.350
Reputation: 19 777
2Note that if the short were contained only to the USB header itself, on many modern motherboards it would probably be fine, since many motherboards now have fuses on the USB ports. That said, given this damage is in the traces on the board itself, I agree with this answer. – Moshe Katz – 2018-10-09T14:53:14.077
You may be able to just Not Use That Port anymore, and just use other ports. However, we don't know what other traces were running nearby the visibly-damaged part. I would leave it physically disconnected, back up everything and move important functions to another PC, until I'd replaced the motherboard. My maxim : always assume it will catch on fire. – Christopher Hostage – 2018-10-09T16:22:21.187
3My assumption is that it's unlikely to burn your house down, but regular backups have saved my bacon many times even without my house burning down.. TLDR; backup important data now, and don't start writing your thesis on this computer. – Aaron – 2018-10-09T20:29:31.423
@MosheKatz If there is a fuse in the path to the actual short here its current rating is clearly much too high! :o – Jamie Hanrahan – 2018-10-09T21:19:56.277
@JamieHanrahan that's why I qualified my statement with saying that I agree with you on this case. Mine was more of a general statement. – Moshe Katz – 2018-10-09T23:01:28.690
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Well, I'd say it is unlikely that it would catch fire. The traces have already burned away as much as they will. And even if they did short-circuit again for some reason, it didn't burn too bad the first time; the PCB material is called "flame retardant 4" for a reason.
I'd say if you are planning an upgrade soonish, you can keep running it in the meanwhile. It's always a good idea to clean any accumulated dust from the enclosure and to check that your fire alarm works, but that applies equally for any PC.
The actual fault possibly resides in the USB connectors in the chassis, so in addition to the motherboard you should change also the enclosure or at least leave the USB cables unconnected.
jpa
Posted 2018-10-09T14:35:01.350
Reputation: 201
Much damage can be done by excess heat in the wrong place even if nothing actually catches fire. – Jamie Hanrahan – 2018-10-10T11:24:49.400
Motherboards are incredibly complex pieces of equipment that can be up to 14 layers thick the complexities of which many users on this site probably don't understand. Others may disagree, but I would ask this on the electronics stack exchange not here. You are far more likely to get a helpful, expert answer from someone familiar with electronics design. – Sam – 2018-10-10T18:32:00.713