What Has Caused This To Happen?

[krazykev64]

This post is not about bad caps as a whole but as the photos show its possible that a tiny cap or similar component could be blown. The burning on the motherboard is clear to see. The motherboard is an Intel OEM board from an Acer computer. I can think of 3 possible causes of the damage.

1/ As the computer was run for long periods with no side cover its possible that a metallic item was dropped on the board while connected to the mains
2/ One of the front USB ports are damged causing a possible short circuit
3/ The heatsink and fan unit was totally clogged with dirt causing overheating.

My guess is the USB port. You will also notice that the damage is very close to the front USB port headers. The model of the motherboard is an Intel D915GAG (SKT 775)

[seanc]

Re: What Has Caused This To Happen?

My take:
The bigger block of burnt crusty stuff was a fuse, the front USB ports got mangled and so it burned up.
Other stuff on the board can probably be cleaned with alcohol and should be OK.

[c_hegge]

Re: What Has Caused This To Happen?

I'm going with cause 2 being the most likely. The fact that the burn is nowhere near the CPU almost completely rules cause 3 out. Cause 1 is possible, but the burned part looks like a smt fuse for the USB header, which often goes up in smoke when there is a short-circuit on one of the ports. The board might actually be OK, but that header won't work untill you replace the damaged part/s.

[krazykev64]

Re: What Has Caused This To Happen?

Too late now as the board has been scrapped. the owner could never get it to run stable and was always having blue screens. what i am going to do is remove the rubycon caps. you might laugh but the replacement for the system is an old pentium 3@700mhz and it runs sweet as a dream. as the saying goes dont fix it if its not broken

[seanc]

Re: What Has Caused This To Happen?

Doesn't mean you can't repair & use the board... unless you've already pilfered parts from it.

[Scenic]

Re: What Has Caused This To Happen?

had the same thing happen on an Abit IC7 (socket 478, i875 chipset).

front USB of the case was jammed, plastic broke off, contacts shorted to the case and the SMD fuse on the board blew..

cleaned the board around the fuse, soldered new fuse in, works fine.
replaced the f*cked up USB port on the front panel of the case and that worked out fine too.

there's always 1 SMD fuse for 2 USB ports. 1.2A is common (2x 500mA per port + some headroom)