AST Bravo 5200 power problem

[FijiJohn]

Working on a donated AST Bravo MS 5200 (P200, 160MB, 10GHB, Win98). When I put in on the bench, it did not start up at all. Took the case off (and a nasty sort of case it is), reseated everything, pushed the power button (with case still off) and up it came!!! (It did have a message that the "case has been opened".) Put the case back on, and started it up just fine a couple of times. Needed to check on the memory configuration so started to take the cover off (1st step being loosen a thumbscrew in the back and slid the bottom panel back a bit so the rest of the case can be puled off.) Just as soon as the bottom panel started to slide the computer stopped. Nothing makes it go - with case on or off. Tried another (known good) power supply and same thing. I CANNOT find any switches (like a case switch) that might have been tripped. Suggestions???

[BipolarBill]

Is it an AT case or ATX? Does the power button "click".

In AT cases, the power supply is turned on directly and then it turns on the PC.

[Rocketmech]

I had an old Dell that gave me trouble like that. The riser card would get dislodged alittle when I removed the case cover.

[FijiJohn]

It's an ATX and I still cannot tell how the BIOS sees a "chassis intrusion" (i.e., where the switch hides). However, I discovered that if I removed the ISA modem card that the computer WORKS again! (I have not tried it yet with the case back on but right now it starts up every time.) If I followed my own advice about removing ALL cards when troubleshooting odd problems I would have saved all of us some effort.