If a resistor blew, it's possible other components were damaged in the process. I would look around for someone with the same board who could take a macro photo of the area, then order replacement parts, then begin replacing most of the components connected in serial or parallel with that resistor. Thankfully my HP Vectra just yells NO when I have a mouse plugged into the keyboard PS/2 port.

Luckly the PC still works... I plan to replace all the resistors and transistors around the same area... i dont know anyone with a board so that is why i posted it here as well. I hope at least SOMEONE has a good AB-BH6

andreja6 wrote:

I recently got an AB-BH6 PC for free from a friend. The mouse and keyboard ports were not labeled NOR colored, so I could not know which one to plug my mouse into. Low and behold, I plugged my mouse into the wrong port and a resistor exploded, leaving an entire brown area on the mobo

Plugging a mouse to a keyboard port (or the other way around) does not blow things up.
Are you sure that was the cause, and the mouse really was a working PS/2 mouse?
Also plugging in devices to PS/2 ports is not recommended when PC is powered up, it is really not meant to be hot-pluggable (the keyboard usually works but I think there's also a risk of frying something).

The picture is not quite good and I was not able to find good pictures of AB-BH6 PS/2 port area, but it may be it was not a resistor but a fuse or ferrite bead.

https://cdn.discordapp.com/attachments/337667 … 1015_161941.jpg <<new image, i put it in a url because it was massive...

I'm not sure if it was the mouse. I got the PC second hand, and the PS/2 ports were blocked off. I just know when I powered it on the PC made a loud BANG and it stunk really badly. I thought it was the PSU, which I replaced, but I also noticed this. The PS/2 mouse was not hot-plugged, it was in during the boot. Afterwards i just was making sure there was no continuity on the black spot then powered it up as usual and the PC booted with a USB mouse and keyboard.

I have used the ball mouse for a while on my new PC, until I switched it to another USB optical mouse I had lying around because the scroll wheel was broken. So I'm sure the mouse is okay.

Hey andreja6. Sorry about what happened. Thanks to the close up photo, it looks like inductor L1 blew.

CkRtech wrote:

Hey andreja6. Sorry about what happened. Thanks to the close up photo, it looks like inductor L1 blew.

That's more like a ferrite bead than an inductor.

Anyway, large currents went through it somewhere, perhaps to PS/2 keyboard or mouse that had a short circuit.
You can measure with a multimeter if the +5V pin on the keyboard or mouse is not connected any more to motherboard +5V.
Looks like this would have been prevented by polysilicon fuses but the board has been manufactured with with 0R jumper resistors in place of polyfuses.

andreja6 wrote:

https://cdn.discordapp.com/attachments/337667 … 1015_161941.jpg <<new image, i put it in a url because it was massive...

I'm not sure if it was the mouse. I got the PC second hand, and the PS/2 ports were blocked off. I just know when I powered it on the PC made a loud BANG and it stunk really badly. I thought it was the PSU, which I replaced, but I also noticed this. The PS/2 mouse was not hot-plugged, it was in during the boot. Afterwards i just was making sure there was no continuity on the black spot then powered it up as usual and the PC booted with a USB mouse and keyboard.

I have used the ball mouse for a while on my new PC, until I switched it to another USB optical mouse I had lying around because the scroll wheel was broken. So I'm sure the mouse is okay.

You first should have asked the person that gave you the motherboard why was the keyboard/mouse ports blocked off before you plugged in the device and applied power. This could have been preventable.

I asked they said they bought it like that. It was just tape

andreja6 wrote:

I asked they said they bought it like that. It was just tape

When you saw that the ports were taped over that should have raised a red flag and you should have checked the ports for the correct voltage prior to inserting a working device.

I didn't even know if the computer worked. they had no idea if it worked either, they got it second hand as well and never used the PS/2 ports because they had no need to, the PC came with a USB mouse and keyboard. The tape was the same kind that you see covering things to prevent dust entering on new products, I did not have much to think about. All I did was plug in the bare minimum, to see if the PC even booted and I heard a loud BANG from what seems to be the PSU.

You'd have to seriously miswire a PS/2 port for it to go bang when a keyboard or mouse is plugged in. Why a motherboard would have PS/2 slots wired like that is a bit weird. Checking the voltage probably wouldn't have helped in this case as too high a voltage would have destroyed the mouse, not the motherboard. It would've had to have been a short circuit (maybe one of the ground pins was actually wired to +5V and then the mouse shorted it to the shield) or more likely just a failing component due to age. Still, the fact that they were taped off certainly does raise some interesting questions...

There's a universal rule about which order the ports go, at least going by every board I've seen. The keyboard port is the first port or the one lower, closer to the board.

firage wrote:

There's a universal rule about which order the ports go, at least going by every board I've seen. The keyboard port is the first port or the one lower, closer to the board.

And it's not true. There are some motherboards that accept mixed input. They just don't care where you plug what.

There may be rare cases where it doesn't matter; I know they've even made a lot of recent stuff with a single PS/2 port for both. Point being, yet to see any system where it's incorrect to plug the keyboard to the left port when they're mounted side by side on the board, or bottom when stacked vertically on the board.