Red light logic board - Apple Power Mac G5 Desktop

Hi. I think that scanner reading sensor is defective. Light has to be white color only.

hi 7 red flashes- main board over heating, can be short on power board or main logic board, thanks

shaun

The logic board is faulty. That chip can't be replaced by normal soldering techniques. Replace the board. If you wish to get some details; visit the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

easy answer I always replace the least expensive part first. If it doesn't fix it at least you have a new part. since the logic board talks to the power board it could be either one.

I don't see that in the service manual. You should give some symptoms and details about the power on LED, fans PSU etc. You need to verify the PSU is good before you get to the logic board.

Sounds like a defective logic board. If you have had electrical storms or power surges it may be a burnt or missing trace on the circuit board.

This is a common problem. There are several capacitors on the power supply and logic board that are bad. Replacement of these parts has restore all units that I have looked at.
On the power supply I would replace at a minimum:
C14 - 4.7ufd 50v UPW1H4R7MDD
C4 - 1ufd 50v UPW1H010MDD
C8 - 100ufd 25v UHE1E101MED
C10 - 470ufd 16v UHE1C471MPD
C12 - 1000ufd 10v UHE1A102MPD

There are 4 others in the supply that were not grossly bad.
C1 - 22ufd 400v EEU-EE2G220
C7 - 220ufd 25v UHE1E221MPD
C11 - Same as C10
C13 - Same as C10

Logic board:
E5 - 33uf 35v EEU-FM1A471
E6 - Same as E5

Part Numbers of replacement caps are Nichicon or Panasonic.

Note: Caps on the logic board are extremely hard to replace due to the internal ground plane.

Contact me if this is beyond your skills for possible repair.

you have logic board problem, check out if the fan, processor , harddisk working if not then it is logic board.
go to apple care and get the assistent.
plz rate this article. if you satisfy..

reset all cables that connected to logic board
if your problem doesn't be ended then u need to buy another logic board