zuldan wrote on 2024-07-07, 06:11:

Whenever I plug in a serial mouse (tried multiple) into a ISA multi IO card on COM1 (or COM2) and then turn on the motherboard, it powers on for 2 seconds then powers off.

Any ideas?

The attachment IMG_5609.JPG is no longer available

For it turns on for a few seconds and then turns off, do you mean the PC?
Or it's the mouse that moves the arrow and then stops.
In the first case I think it's a short, but it could be something else, because the power supply protection should prevent the PC from starting immediately.
In the second case, I hypothesize that those old mice had a switch with two positions, one was MS the other I don't remember, you may have selected it on that wrong position, I think that later, it was done by software, but from DOS you can control it , the driver information that is read.

PC@LIVE wrote on 2024-07-07, 07:12:

For it turns on for a few seconds and then turns off, do you mean the PC? Or it's the mouse that moves the arrow and then stops. […]
Show full quote

zuldan wrote on 2024-07-07, 06:11:

Whenever I plug in a serial mouse (tried multiple) into a ISA multi IO card on COM1 (or COM2) and then turn on the motherboard, it powers on for 2 seconds then powers off.

Any ideas?

The attachment IMG_5609.JPG is no longer available

For it turns on for a few seconds and then turns off, do you mean the PC?
Or it's the mouse that moves the arrow and then stops.
In the first case I think it's a short, but it could be something else, because the power supply protection should prevent the PC from starting immediately.
In the second case, I hypothesize that those old mice had a switch with two positions, one was MS the other I don't remember, you may have selected it on that wrong position, I think that later, it was done by software, but from DOS you can control it , the driver information that is read.

The whole PC turns off after 2 seconds, as if the power supply detected a short. If I power the PC on without the mouse connected, it works fine and stays on. As soon as I plug a serial mouse in, the computer powers off.

I think I’ve seen this before. I recall it had something to do with the jumpers of the Multi IO card. I would be very surprised that both Multi IO cards would be shorting 🤨

zuldan wrote on 2024-07-07, 07:16:

PC@LIVE wrote on 2024-07-07, 07:12:

For it turns on for a few seconds and then turns off, do you mean the PC? Or it's the mouse that moves the arrow and then stops. […]
Show full quote

zuldan wrote on 2024-07-07, 06:11:

Whenever I plug in a serial mouse (tried multiple) into a ISA multi IO card on COM1 (or COM2) and then turn on the motherboard, it powers on for 2 seconds then powers off.

Any ideas?

The attachment IMG_5609.JPG is no longer available

For it turns on for a few seconds and then turns off, do you mean the PC?
Or it's the mouse that moves the arrow and then stops.
In the first case I think it's a short, but it could be something else, because the power supply protection should prevent the PC from starting immediately.
In the second case, I hypothesize that those old mice had a switch with two positions, one was MS the other I don't remember, you may have selected it on that wrong position, I think that later, it was done by software, but from DOS you can control it , the driver information that is read.

The whole PC turns off after 2 seconds, as if the power supply detected a short. If I power the PC on without the mouse connected, it works fine and stays on. As soon as I plug a serial mouse in, the computer powers off.

I think I’ve seen this before. I recall it had something to do with the jumpers of the Multi IO card. I would be very surprised that both Multi IO cards would be shorting 🤨

Ok understood thanks.
Well it seems like the problem is the mouse, have you tried another one?
Then I don't think that both cards are defective, the ideal would be to use cards and mouse from another working PC, and if the PC turns off then the problem could be in the MB.

PC@LIVE wrote on 2024-07-07, 08:33:

Ok understood thanks.
Well it seems like the problem is the mouse, have you tried another one?
Then I don't think that both cards are defective, the ideal would be to use cards and mouse from another working PC, and if the PC turns off then the problem could be in the MB.

I managed to find the problem. The video card was shorting the 5v line on the motherboard. Weird!

Got rid of the video card and now the Multi IO card is working now. Thanks for all the suggestions!

Well, great job.
Interestingly, neither the mouse nor the controllers were faulty, strangely when you connected the mouse, the VGA was somewhat stressed, and perhaps the problem was a coincidence that arose when connecting the mouse.
It would be interesting to understand the VGA problem, if it can be solved, maybe there is some capacitor that needs replacing.