chip layout in IBM PS/2 30-286

[tezza]

Hi,

I have two non-working PS/2 30-286s . One has a motherboard issue and the other has a video fault. Given the LSI IC's, surface-mount components and general complexity compared to earlier machines I have little hope of fixing them.

However, more to satisfy my own curiosity more than anything I'd like to probe around with the scope and see if I can figure out what circuitry is at fault. I've got the PS/2 hardware maintence manual and a detailed document on PS/2 video. What I want though is a motherboard schematic showing the chip layout which identifies which ICs do what? The codes on the ICs don't mean much to me.

I've looked and looked but can't find anything like this on the Net. Can anyone help?

Tez

 

[tezza]

Oh, I should mention I do have this which does show the IC layout. But there is no indication of what those ICs actually do.

I need some kind of fairly detailed description of their functions.


Tez

 

[mikey99]

What type of video fault does the machine have ? Does that have onboard video ? Can you use an ISA video card instead ?

 

[tezza]

What type of video fault does the machine have ? Does that have onboard video ? Can you use an ISA video card instead ?

It's described in the first post above. It's not the power supply as was suspected in that thread. Basically, it doesn't show anything. It's like it doesn't activate the monitor, although it's enough to take a monitor out of sleep mode. Yes, it's onboard video. I've tried adding another video card, but no luck there either.

The weird thing is on one or two occassions it's actually started working....for a brief while. So it's not absolute.

Tez