Macbook Pro 15" A1226 EMC: 2136 - Hard Drive Spins, but no start up chime.

[0349932]

I'm home sick with the flu so I thought I would use the time to start work on a MacBook that I bought that from eBay. The seller described a common problem where the MacBook would think it was on when the lid was closed and when the lid was opened, it would shut off. I thought it sounded like a PRAM battery problem which I could easily fix. While I was waiting for the new PRAM battery, I installed my own hard drive from an old Windows laptop that I used Disk Utility to format and installed Yosemite successfully. I also bought a new battery, power adapter and upgraded the RAM to 4GB.

Before the new PRAM battery came I ran into an issue where once the computer was shut off, it has difficulty starting again. When I depress the power button, I can hear the hard drive spinning, but there is no further boot activity. No start up chime and nothing on the screen. Just the hard drive spinning. I've tried an SMC reset and also a trick to bypass the SMC by plugging in the Magsafe whilst holding the power button. No luck.

I feel like if I could get the computer to boot and reset the PRAM with the new PRAM battery, there is a chance that all could be well, but without a proper boot up with the start up chime, I'm dead in the water. I'd really like to get this computer running so any and all advice or recommendations the community has would be greatly appreciated.

 

[Bomb Bloke]

Can't say I'm completely sure on this, but I'm pretty sure changing the RAM configuration of the system should force a PRAM wipe automagically. Try pulling all RAM out, booting the system, then putting one chip in, starting again, then finally filling all banks once more.

It sounds like you can still get the system to boot "sometimes", but not while attempting a traditional PRAM reset. In that case, you could always clear PRAM via the Terminal:

sudo nvram boot-args="-p -r"

 

[0349932]

Bomb Blake,

Thanks for your recommendation. I followed your suggestion and oddly enough, even with no RAM in the laptop, the same symptoms still persist. When I hit the power button, the hard drive will initialize, but nothing else. I re-loaded the RAM and it still won't initialize. I know that this computer works. I loaded Yosemite onto it last week! I'm pretty sure it went to sleep the last time it was running instead of being switched off. If you can think of any additional information I could add that would be helpful, please let me know. I'm keeping my fingers crossed that with your help and the community, I can get this MBP to boot again.

Thanks.

 

[Bomb Bloke]

Hrm, so you really can't get it to start "at all"? That's not a good sign... I really hope a component hasn't blown somewhere. Odds are it'll be on the logic board if so, and I'm sure you know how that song and dance goes.

Try another SMC reset - just to be sure you've got the right info, remove the battery and charger, hold the power button for at least five (ideally ten) seconds while they're still disconnected, then let go and re-assemble.

Failing that, it may be worth switching PRAM batteries again (or, if you no longer have the old one, simply trying things with no such battery at all). No joy? Then proceed to start swapping the other old parts back in, too - perform another SMC reset after each one, and retest.

If she still won't POST after all that, then I'm afraid you're likely SOL. At least, I doubt there's much else I could suggest if there's still no change.