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frizbon
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MacBook Pro a1286 won't turn on, possibly water damaged.

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My boss approached me and asked me to take a look at his wife's Macbook Pro 1286. The serial number identifies it as a mid 2009 model.

The computer had been having problems with it's old series mag safe connector. The connector sometimes displays no light, or a dim green light, rather than the normal bright green or amber lights.

Apparently, water was spilled "around" the laptop but not directly on, getting the bottom of the case wet. After this occurred the laptop would no longer turn on. It remains unresponsive if the power button is pressed.

I have reset the SMC and the pram, but this has had no visible effect. I reseated the ram, trying the computer without it, and with each stick in each slot. In all instances the computer remains unresponsive.

Opening the case, there was a small spot of corrosion on the board near the power plug for the rightmost fan (assuming that the board is positioned such that the fans are at the top of the board). I removed the board entirely and investigated, but found nothing else. I cleaned the board using rubbing alcohol and reinstalled it.

However, the computer remains dead to the world. I suspect that the motherboard is simply fried and needs to be replaced, however the earlier power issues make me cautious. Can any one recommend a way to rule out the dc in board or the power supply as sources for the issue if I don't have known good spares for those components? Alternatively, can anyone recommend a diagnostic or repair step that I might have missed?

Edited by: frizbon ( )

You say nothing about the battery - if it's dead and there's low voltage to the board you could get no boot. A dim green light could be a ground (center) pin on the magsafe... it "controls" the light. Check the magsafe pins are not corroded or stuck.

machead3,

The battery reportedly worked before the incident. Most of my testing has been repeated with and without the battery, with no noticeable effect. During my initial attempts to diagnose the power issue, I left the battery in and plugged the power connector on. It entered a charging cycle (magsafe showed amber light), which it exited some hours later (magsafe showed bright green). When I removed the plug and plugged it back in, the connector went straight to bright green. I'm having to infer a lot, but this seems to indicate that the DC board works on some level, and that the battery will take and keep a charge. It's possible that the system is broken in such a way that the battery is not charging, or is charging incorrectly, but with the tools I have on me I can't say yes or no to that, as far as I know. One other thing, I mentioned that the SMC reset had no effect, but that wasn't quite true. It did affect the color the of the mag safe LED, but I assumed that was the expected behavior.

frizbon,

I have not tried that. Taking a look at the board, I don't believe that the picture you provided corresponds to the motherboard on this laptop. The image appears to place the jumpers to the right of the ram slot, if the board was rotated such that the fans faced me, and the board was laying processor side down. However, I don't see the corresponding structures. Any suggestions on what I might be doing wrong?

frizbon,

Try this Question for Answer to jumper.

machead3,

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machead3
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Try booting with no RAM - If you get no EFI RAM warning I'd say the board (at least the EFI chip) is toast. IF you do get the warning replace One chip, try the chip in each slot. Try the other Chip.

Good Luck,

I tried this in my initial tests, and got no sound what so ever, which seems to lend itself to the dead board theory. However if it's a power issue, then I would expect the same behavior. I may have a line on a duplicate charged battery, which would provide, I assume, the final bit of evidence.

frizbon,

Well if you want to entirely rule out no power I suppose you'd have to replace the DC in board. It could be a fault there would also not allow a boot OR a POST at all.

machead3,

Battery power should bypass the DC in board entirely though, shouldn't it?

frizbon,

Mayer seems to think a good battery would boot a machine with a bad DC in... I don't know.

machead3,

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