No boot. Black screen. No chime.
== Is it my logic board? or my top case?== mine is the model with the 3.06GHz processor and a matte screen.
My computer was fine until April 2010, when I returned from 2 weeks in Haiti [volunteering, not a holiday] with HD errors [was left in backpack, in full sun for an hour one day]. I replaced HD with a Seagate Momentus Solid State Hybrid SATA Drive. Blew out some dust with compressed air since the case was open.
Optical drive stopped reading and writing in Nov 2011. So, I started copying over firewire to the dvd burner on my old powerbook. I often keep the Macbook pro running for a week or so before rebooting... but I run disk utility regularly, and repair permissions every month or so. Otherwise, everything was fine until it stopped dead last week. I went out for groceries, came back... dead. It was running when I left. It was cold. No boot, no chime. It was connected to an external display, so I knew it wasn't just the backlight. I read a lot here, at ifixit, to try and figure it out.
I followed the apple troubleshooting and disconnected all the peripherals and zapped the PRAM, reset the SMC, to no avail. If I held down the power I could get the fans to spin up and the tiny light at the front to go on, steady. But that's it. Since I have no applecare, I cracked it open and swapped RAM in and out to see if it has gone bad. While was in there, I blew out some dust. The heat sink [the long twisty one from the fans across the chips] had obviously been hot: it had slightly adhered to the black plastic that covers the keyboard. I feel like it has been running hot, but I cannot quantify that with numbers.
I checked the logic board for anything obvious and saw a small amount of corrosion on the board near the audio jacks and card slot. Mostly, the solder appeared dull compared to the rest of the board. I cleaned it with 99% alcohol on a little brush. I was checking it out with a loupe, and I could see dust on everything, so I gave the whole board a bit of a once-over with the alcohol/brush.
I put everything back together. No chime, no signs of life of any sort [except the battery gauge responds accurately]. The battery charges, the adapter goes from orange to green. I was pretty careful with discharging static before cleaning the logic board. There may have been a tiny splash of coffee a couple of days before this happened [-- it was on the speaker grille on the DVD side of the case, and there is no evidence of it inside the case, but I have not burrowed into the keyboard].
I disconnected the HD, optical drive, airport, bluetooth, battery gauge, one speaker, keyboard backlight, trackpad and keyboard. I kept the display connector connected [and the speaker and mic on the other side of the LB]. From the keyboard connector, I connected the fifth pin from the left to ground with the power adapter connected and the fans powered up. No other signs of life [as far as I could tell] -- no chime [but one speaker is disconnected], and there is nothing else connected to light up... but the display doesn't do anything.
I reconnected everything except the keyboard and optical drive. Powered up again with the contacts on the keyboard connector: the fans, front "sleep light" and HD power up. Still no display, or chime.
I connected my ipod to a usb port to see if it charges. It doesn't seem to. I am a bit freaked out, since I spend about 12 hours a day working on my computer [image processing, video editing, writing, browsing, my only phone is voip, and some large file transfers regularly].
It has been very dry here. I have accidentally zapped the trackpad numerous times with static electricity.
Is my logic board a goner? I have a multimeter but don't have any idea of what to check, or where... I am grateful for any suggestions, because i am at a bit of a loss here, and I don't know what to do next. If I borrow a usb keyboard should I try to safe boot... would that even work?? could it just be the top case? Please advise....