The white G5 iMac is a machine that often fails due to issues with its capacitors and power supply.  In general if you have one of these machines and it all of sudden starts shutting down during startup, freezes with the fans running at full speed, or simply fails to turn on at all chances are you have such a machine.

To open the machine is quite easy,  you can simply loosen the threes screws on the bottom with a phillips screwdrive and pull the back off the unit.

First place to look is at the capacitors themselves, this unit is known for having defective capacitors that bulge and leak, so if you see any – then stop machine is dead (not worth the repair costs for new logic board).

Here is a closer look at a bad one.

You can see in the photo two of the capacitors are shot.¬† Since apple no longer has a program in effect to fix these units at their costs, if you have one with bad capacitors it is probably better to harvest for parts.¬† Out of six old machines that were all “Dead” I found three with this issue but was able to rebuild the other three just taking parts off of the ones with the capacitor issues.¬† The Ram, Power Supplies and Drives were still all good.¬† Considering a G5 power supply runs over 100$ harvesting the units for power supplies is worth the effort.

Interestingly, even after swapping some logic boards (when apple was still honoring a program of repairing for free)¬† I found that some units after a year would have the same issue.¬† I am guessing that the doomed G5 may have been a hot processor and that the poor machines could not keep the board cool enough,¬† check out where the capacitors are in relation to the heatsink,¬† if you have ever heard the G5 when its fans are going you know it is getting hot.¬† Perhaps this model was simply a design flaw – all in all the newer Intel based iMacs do not have this issue what so ever and are very reliable.

Too close to hot processor?

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