iMac 20" A1174 dead, but +/-12VDC at PSU
Hi All !!!
Got an iMAC Model# A1174. 2006. 20" display. Last 4 of the SN are VU2S.
When you press the power button, NOTHING happens.
Disassembled the unit. What I discovered is: Power button tests good. If I DISCONNECT the multipin connector on the motherboard (logicboard?), then plug the power cord in, I hear the HDD spin up. No fans nor LEDs, just the HDD. if I re-connect the multipin connector on the motherboard, then plug the power cable in, nothing. Press the power button and again nothing.
Measurements:
With system normaled up but display and multipin connector removed I have the following on the PSU :
Grey wire 1 = +12VDC
Grey wire 2 = -12VDC
If I re-connect that multipin connector back into the motherboard, I get 0 VDC on those grey wires. With the multipin connector disconnected and the power cable plugged in, I can read various DC voltages (5, 3, & 12).
I have a bad feeling that the problem is possibly with the motherboard since the multipin connector has all the appropriate voltages on it before I plug it back into the motherboard.
Any ideas of how to test the PSU any further, or how to isolate this problem better?
THANKS ALL in advance!
Rob
Is this a good question?
2 Comments
Any one else have any ideas?
by Rob
@rms8 can you go on here http://www.everymac.com/ultimate-mac-loo... and identify your iMac for us completely?
by oldturkey03