VOGONS


First post, by oldgames79

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Newbie

Hi,

I have a voltage problems on my port COM1
My motherboard is a FIC 486 VIP PIO2 and my mouse doesn't work because I have +12v on all pin except on pin 4,5 and 7. There is no -12v. I have tested the PSU and there is -12v.

I have tested a serial port on an other motherboard where my mouse work and there are -12v on pin 2 and 3 and nothing else on the others pin.

Someone already had this problem.

There is a problems with the controller or the controller is defect?

PS: I have also tested the port COM2 and the problem is the same.

Reply 1 of 2, by SSTV2

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Rank Oldbie
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I had this exact problem with one of the 486 MBs. If you don't see -12V on the ISA slots, then you have the exact same problem as I did - corroded AT PSU header pins or corroded AT PSU connector pins.