shorted SWIM IC. Replace it. if you get current crowbarring without the display, this IC is bad.
Pull it and check other surrounding ICs for overheating signs using the finger test. sometimes when the SWIM goes, it knocks out a number of them. including the group of them between the CPU and the GPU, and sometimes one of the buffer IC goes in the RAM section just above the -5V regulator.
If you get current/short issues with the display connected, you likely have the cable wired wrong, or the display itself is shorted, or more likely, the inverter itself.
The symptoms you describe with random power-offs after startup, is cap goo current leakage between vias near the comparator IC to the right of the two reset/NMI buttons.
Its rare, but sometimes if the cap goo was bad enough, it will leak through the inner layers of the board and cause issues like this. The only solution is to locate arbitrary resistances in the PCB that arnt normal, and bypass that by cutting/rerunning traces. Only fix....
Pull it and check other surrounding ICs for overheating signs using the finger test. sometimes when the SWIM goes, it knocks out a number of them. including the group of them between the CPU and the GPU, and sometimes one of the buffer IC goes in the RAM section just above the -5V regulator.
If you get current/short issues with the display connected, you likely have the cable wired wrong, or the display itself is shorted, or more likely, the inverter itself.
The symptoms you describe with random power-offs after startup, is cap goo current leakage between vias near the comparator IC to the right of the two reset/NMI buttons.
Its rare, but sometimes if the cap goo was bad enough, it will leak through the inner layers of the board and cause issues like this. The only solution is to locate arbitrary resistances in the PCB that arnt normal, and bypass that by cutting/rerunning traces. Only fix....