Hi! I've got an A1211 that works fine after it's been sitting for about 30 minutes without AC or battery, and with the PRAM battery disconnected. If I re-connect the PRAM, and power up, it works as long as I keep it on, but when I shut down and power on again (or even just reboot) I get a solid sleep slight, no light on the screen, and no chime. Interestingly, when it's in this state the PRAM will not reset, and the PMU will reset, but I don't hear a solid tone like I normally would. The machine will not power on properly again until it's left alone without AC, battery, and PRAM battery. If left in this state with power, the fans eventually spin up at medium speed.

As far as what I've tried, I've tested the RAM and slots, I've removed the battery entirely, and I've taken out and cleaned the board. There is no optical drive installed. There was no liquid damage, although there was a lot of dust.

Nothing has helped, and the board seems to have this problem permanently. Unfortunately I don't have another I/O card or logic board of this model to test with.

Any ideas?

Thanks,

John