bhtooefr
Experienced Member
If you get one of these motherboards, or a system with one installed, be careful with the speaker wiring, as they don't use the XT speaker wiring pinout!
I found this out the hard way when putting an original XT motherboard in my 5155 that came with a VIP TXM/10-II, and almost got burned. Literally. The speaker plug had been rewired to match the VIP board, which has a pinout like this:
UNK KEY SPK GND (I don't know whether +5V is available on pin 1, safest to assume that it is.)
The XT pinout is:
SPK KEY +5V GND
After having run overnight in the incorrect configuration, my speaker was extremely hot. Amazingly, it didn't burn out, and after swapping the wiring back to the XT configuration, it worked fine. Interestingly, I was getting extremely weak sound from the speaker with the wrong wiring, all I can figure is that there was a tiny amount of noise on the +5V/GND lines that was making it into the speaker.
I found this out the hard way when putting an original XT motherboard in my 5155 that came with a VIP TXM/10-II, and almost got burned. Literally. The speaker plug had been rewired to match the VIP board, which has a pinout like this:
UNK KEY SPK GND (I don't know whether +5V is available on pin 1, safest to assume that it is.)
The XT pinout is:
SPK KEY +5V GND
After having run overnight in the incorrect configuration, my speaker was extremely hot. Amazingly, it didn't burn out, and after swapping the wiring back to the XT configuration, it worked fine. Interestingly, I was getting extremely weak sound from the speaker with the wrong wiring, all I can figure is that there was a tiny amount of noise on the +5V/GND lines that was making it into the speaker.