Resolved 20" iMac: video problems after installing new HDD

[iCantfixit]

I have a 2006-ish 20" iMac. The hard drive was clicking and basically died. I removed the drive and was unable to access anything on it using linux on another computer. The old drive was a 250gb Western Digital Caviar SE.

I have a 7200rpm 1TB Seagate Barracuda. I installed this drive into the iMac and tried booting to my snow leopard install disk. The power light comes on and the screen flashes white when it powers up then both go off. The mouse light remains constant during all of this.

You can hear the CD reading afterwards, however the screen and power light remain off. After some time(5-10 minutes) the power light comes on and if you press a key or move the mouse the initial Snow Leopard install screen (prompting language selection) appears for 1-3 seconds, then the screen goes black again. I waited several minutes longer and this repeats.

Attempted to access the drive using firewire target disk from a macbook pro, but did not see the drive. I also double checked all the lcd connections, HDD connections etc. The memory was reseated. The OSX install disc cannot be ejected since there is no response when pressing the eject key.

I am wondering if there is some compatibility problem with this hard drive or is there even a restriction?

Might I have caused an issue with the LCD when reassembling the iMac? However why would the screen display anything if this was the case?

Anyone have any ideas or advice on this one?

Any help would be appreciated

Thanks,
iCantfixit

 

[MatthewAMEL]

Have you tried using this guide?

http://www.ifixit.com/Guide/iMac-Intel-20-Inch-EMC-2105-and-2118-Hard-Drive-Replacement/1092/1

I would start there. Take it apart and reassemble following the guide and see if the problem persists.

It sounds like it's not specific to your monitor since you couldn't see you HDD in Target Mode.

However, it's all too easy to miss a connection or have something make intermittent contact when working on iMacs.

 

[iCantfixit]

Thanks for the link. After going over everything again and checking that the drive was functioning using diskpart, I have found the problem!

A pin on one the top LCD connectors had been bent. Straightened the pin, reassembled the iMac and now installing the OS on the new 1TB drive.

Of course the most simple thing is always the problem, I always forget to check the 'pins'.

Thanks for the help, I guess 'iCanfixit'.