Is my iMac G5 PPC screen dying??

Some imacs sufferd from failing electrolitic capacitors.

Basically the larger electrolitic capacitors bulge, leak and eventually fail.

There is little that you can do about this other than take it to a computer store who are capable of changeing all the ofending electrolitic capacitors.

Some people sell kits of capacitors on ebay and some companies offer a repair service specifically for this fault.

It is a well known, and publicised fault, which can affect the graphics, cpu (causing freezes), and the power supply.

I have had two G5 imacs with this fault.

G5 has these hardware issues:

-- bad capacitors on logic board

-- bad capacitors in power supply

-- badly soldered video chip

-- "There were several Mac models with flat panel displays that had bad displays.

Most had serial numbers beginning with "W8"---the code for one specific factory.

This affected PowerBooks as well. If that's the case, the rest of the computer

is probably fine." by Allan Jones in

https://discussions.apple.com/thread/4922592?answerId=21630224022#21630224022

Google: g5 capacitor replacement kit

More info on capacitor replacement kits

http://jimwarholic.com/2008/07/how-to-repair-apple-imac-g5.php

http://thecapking.com/applg5.html

It's not a hunch, it's a fact that was well publicised and Apple did support a lot of people with the problem when it happened.

The faulty capacitors could cause a variety of faults from screen problems to CPU freezes.

Even the capacitors in the power supply could be affected but they would not power up.

The capacitor issues are in Wikipidea

Capacitor plague - Wikipedia, the free encyclopedia

And the repair solutions are here.

Apple iMac G5 Motherboards DIY Repairs Bad Caps Fix How to Guide | According to Jim

I spent a lot of my life working in the electronics industry and studied electronics.

I brought a kit of capacitors on ebay for this repair.

The nature of modern electronics production and the very high temperature flow solder technics make this repair very difficult.

I'm sorry if you think this is a hunch but it's not.

Many thanks Jeremy

HI Petra,

Don't worry I'm a slightly pedantic and perfectionist person myself so no offence taken.

I was just a little bit surprised that you had not done a search which would show you the extent of the problem.

The chances of using an external display are limited as the dispaly output would most likely have the same problem.

The hard drive could be removed and fitted to another computer to rescue the files and information.

In terms of fixing the computer, I was a very experienced electronics engineer, now with MS so a bit cack handed, but still keen to fix things if I can.

I invested in a very expensive bit of professional Japanese made desoldering equipment which could achieve temperatures of 350º but I still could not remove the components easily so I gave up.

In the end I even tried "Drilling" the capacitors out with a special tungsten carbide drill but found it extremely difficult to not ruin the motherboard.

If you Google the subject "imac G5 capacitors" you will get a variety of information, and videos on youtube showing people with varying degrees of skill and ability, and success trying to fix these problems.

There is a company on ebay which offers a recapping service for imacs and they have a special CNC drill to drill out the capacitors.

They will only touch computers which have not been tampered with.

good luck

Jeremy

Lets rule out OS X software. Try this.

The startup manager will list all of your bootable partitions then give you a choice of which to boot.

Try holding down the option key then power on. This brings up the startup manager. Click on your hd. Click on right arrow key.

Well you tried

-- safe mode

-- booting to startup manager.

i'd guess it was the lcd display.

the g5 does have a mini-vga port. you could try connecting to a vga display with an adapter.