Greetings all, first post here. I picked up a Compaq Portable I at a hamfest today - known non-working, but the price was definitely right to take a stab at fixing it. Fortunately it's almost completely dead, meaning it seems likely the problem is in the PSU. The line fuse is fine, and the cooling fan runs normally when I switch on the power, but none of the internals appear to get power. If I flip the switch while I've got the computer opened up enough to observe the insides, I can hear a little pop that might be coming from the speaker, and there's a red LED on the motherboard that flashes on for just a split second.
This one appears to have some added hardware, as it's got dual 3.5" floppy drives (not sure if they're 720K or 1.44M) plus a hard disk of some sort. There are four cards in it, two of which appear to be the factory-installed I/O and video cards, plus a hard disk controller and some other expansion card that appears to have some RAM and/or EMS plus more I/O. I've tried powering on the machine with all four of these cards pulled out, with the same results. When switched on, I don't read any DC voltage across any of the pins on the molex connector that powers the two floppy drives.
Any recommendations what I should check based on these symptoms? I'm absolutely not an EE, but I'm handy enough with a soldering iron and multimeter, and I've recapped a few things and built a couple computer kits (Altairduino, MiniPET), so dumb it down appropriately for me.
This one appears to have some added hardware, as it's got dual 3.5" floppy drives (not sure if they're 720K or 1.44M) plus a hard disk of some sort. There are four cards in it, two of which appear to be the factory-installed I/O and video cards, plus a hard disk controller and some other expansion card that appears to have some RAM and/or EMS plus more I/O. I've tried powering on the machine with all four of these cards pulled out, with the same results. When switched on, I don't read any DC voltage across any of the pins on the molex connector that powers the two floppy drives.
Any recommendations what I should check based on these symptoms? I'm absolutely not an EE, but I'm handy enough with a soldering iron and multimeter, and I've recapped a few things and built a couple computer kits (Altairduino, MiniPET), so dumb it down appropriately for me.