First post, by jarcher1701
Hello. Hoping some knowledgeable folk might be able to help.
I purchased a 386/486 combi motherboard on eBay along with a ATX to AT power supply adapter. I'd powered it on previously, hooked up via VGA to my 1080p monitor, and I just got a black screen. The 486 DX CPU was powering/heating up, along with other components. I tried again today with a different VGA cable and this time, after leaving it a while, a tantalum capacitor blew up (my eyes were a safe distance away thankfully).
I'm using a 10 year old (approx) ATX 250W power supply. I haven't — although probably should have — tested with a mustimeter first.
I have a Cirrus Logic GD5428 in the VLB slot. I bought it untested, so it could be the issue, but it looks absolutely fine.
I have a PS/2 keyboard (with adapter) connected. Before the capacitor blew, the keyboard was being powered and I was able to enable and disable num lock.
Photos are below of the board and blown cap. Any advice regarding the black screen and next steps regarding the blown cap? Many thanks in advance.
Edit - I also removed the battery. It had leaked slightly, with only minor green corrosion nearby which mostly came off. No damage to tracks. Would a lack of battery result in a black screen? I'm doubtful.