I think I just killed my iMac G4 (17" 800mhz) - How to fix?

[daver_cl]

I've got a 17" iMac G4 800mhz (2002) and took it apart today to replace the hard drive and upgrade the RAM. Here's exactly what I did:

1: Disassemble according to the instructions here: (


)
2: Gently vacuumed dust out of the case, trying very hard to not touch any metal components. Did not touch the logic board.

3: Added 60gb SSD (using a SATA to PATA adapter I bought on Newegg)

4: Added 512mb RAM bought from OWC into the non-user-accessible slot

5: Scraped off old thermal paste and applied new paste

6: Reassembled the case

7: Re-inserted the AirPort card and 512mb user-accessible RAM

8: plugged in and powered on

When I did this, the machine made no sounds, neither from the speakers or mechanically. The top fan did not spin up and, to my horror, the computer began emitting a strong ozone odor. I immediately unplugged the machine and let it sit for a few minutes.

I took it apart again and visually inspected the main logic board. I'm not skilled with logic boards or soldering or anything, and didn't notice any blown capacitors or visual damage. I replaced all of the original components that I had replaced and re-applied the thermal paste again, and (against my better judgement) powered it back up. This time I got the chime through the speakers and a brief flash on the screen, but then nothing. Still no fan noise or hdd spin-up. I tried again without the speakers plugged in, and the chime came through the internal speaker sounding like it was underwater. It was working before.

Did I fry the logic board? Is the PSU gone? Can I fix it, or should I start constructing a lamp? Any help would be greatly appreciated!!!

 

[uniserver]

i always use an air compressor to blast out the crap, a vacuum is not going to get hunks of dust/filthy in areas you cant see,

so maybe you pushed a hunk of crap into the psu area and it shorted out…

or when you put the computer together there is a header that has pins that all line up, they can get bent over, cause a short,

also when you attached the SSD, maybe you some how crossed the power with the SATA to IDE adaptor.

i would start by blasting it out with a real air compressor and a blow gun.

 

[Byrd]

Start again, it's not too bad disassembling an iMac G4. Ensure that your thermal paste isn't conductive and clean any remnants off with isopropyl alcohol wipes. Just a thin layer of the cheap white silicone goop is all you need on the heatsink "base". Also those PATA to SATA adapters don't work very well either, so perhaps disconnect the SSD when you try to fire it up. Double check all connections too, some need a firm push to go back in.

JB

 

[jongleur]

I recently did some work on an iMac-G4@800 I picked up. When I was putting the drive caddy back in place, I hadn't pushed the power Molex connecter in firmly all the way (very tight fit). Opened it up and redid the connecters, and all is good. Those PATA/SATA adapters are finicky, make sure all the connections are good, and that there is no pressure on the connectors. Maybe some small cable ties and/or electrical tape to fix the connectors in place.

 

[krye]

Vacuum cleaners should never be used on a computer, unless it is a handheld DC powered one designed for such a use. AC powered vacuum cleaners can induce a voltage (static). Very bad for static sensitive electronic components.

 

[trag]

If the other suggestions don't help, in general, in cases like this, it's useful, but tedious, to go back to the original configuration to eliminate variables that could be causing the problem.

So if all else fails, pull the new RAM, make sure none of the heat sink grease you applied has run off onto electrical connections (it's usually electrically conductive as well as thermally conductive, I killed a PCC Power 120 logic board by overapplying heat sink grease, once), remove the hard drive (no need to install the old one) and try again. If you a good start up bong and the screen displays, then do it all again, and reinstall the RAM. If it's still good, reinstall the hard drive.

Like I said, tedious, but sometimes the only way to narrow a problem down to one culprit.

If the heat sink grease has gotten into the connectors, pull the whole circuit board, if you can, and thoroughly wash it to remove all the excess grease. A can of spray circuit board cleaner is handy in those types of situations, such as Flux-Off.