MacBook A1342 turns on, but will not boot

New to the forum, please be gentle...

I have a MacBook A1342. It's fully charged, green light on the magsafe. Press the power button, the power light comes on, fans, then nothing. After about 5 seconds it switches off, and tries again. Same thing happens, except it doesn't reboot a second time.

I've opened it up, tried with and without the battery connected, battery but no mains, tested both RAM sticks and slots. Stripped it down, cleaned it up, renewed the thermal paste, then reassembled, and it worked! Shut down, restarted, still working. Shut down, restarted, back to original problem.

I've tried an SMC reset, PRAM reset, and am totally stumped as to what else it could be, other than a generic "Logic board failure". But if that's the case, how did it work twice after stripping/reassembly, but not any more?

Searched online for 2 days solid, without finding a possible answer. Open to all suggestions before I bin it!

That's a mid 2010 MacBook - just for identity purposes. It sounds like your DC input board could be defective. I haven't heard of many (actually very few) MacBooks that had a defective logic board. It's always possible of course but chances are it's not the logic board. Check the ifixit web site and powerbook medic web sites to see if you can locate a DC input board and what the cost would be. The ifixit site will also have instructions on how to change it out. Just on the chance it could also be the MagSafe Adapter Charger, you should try swapping that out first if you can.

Thanks, I'll give it a try

Make sure you try the MagSafe Adapter Charger swap first. I edited my reply to include that and you probably missed it.

Pardon my ignorance, but if the charger/DC board was faulty, would it still show some signs of life, as mine does? The fans spin up, as does the hard drive, and the power light comes on.

Topher_UK said:

Pardon my ignorance, but if the charger/DC board was faulty, would it still show some signs of life, as mine does? The fans spin up, as does the hard drive, and the power light comes on.

Click to expand...

Yes it would. It could be intermittent in that sometimes it will work and then not. But the same can be said of the MagSafe Adapter Charger. If it does somehow turn out to be a defective logic board, it would probably be too expensive to replace it. In that case you would be better off using the repair money toward a newer machine.

If you're near an Apple store, you might want to take your MacBook to them and let them run diagnostics on it. I don't know if there would be any charge for that since you're in the UK. Here in the US Apple store diagnostics are generally done for no charge.

OK, thanks for the advice