Imac G5 20'' Recap... Shades Of Blue

[cheebster]

Hi. First of all, thanks for this great forum to all the contributors.

I just recapped a imac G5 20''. The caps all looked good, all Rubycon MCZ. I think i did it all (24 6.3V 1800uf, 5 16V 1000uf) for nothing, the issue i had is still there.

After digging a bit more here, i found out the issue was located in the psu instead (Ltec caps...). After opening up the psu, they all LOOK fine. Are they fine, don't know.

Should i buy another recap kit to do this part as well ? All the imac does is booting to a blue screen where it shifts from diff. shades of blue, which seems to be rather common with these units.

Thanks for any input..

[cheebster]

Re: Imac G5 20'' Recap... Shades Of Blue

Bump !

[stj]

Re: Imac G5 20'' Recap... Shades Of Blue

looks can be deceiving.

[cheebster]

Re: Imac G5 20'' Recap... Shades Of Blue

Yeah. But this time, i lost my time i think. Is the psu the source of my issue, anyone thinks ? (the ltecs..)

[godonr]

Re: Imac G5 20'' Recap... Shades Of Blue

Do a search here for "Imac G5" and you'll find a wealth of info. As far as the p/s, you need to verify the voltages. Unplug from m/b and jumper 15+16 to turn p/s on. You should see 24vdc on 22. Not sure where it is but there's a list of the other voltages here also. If you have the Apple Service Diagnostic, you should run it. Also, don't rule out a bad OS load or hard drive as the problem.

[PCBONEZ]

Re: Imac G5 20'' Recap... Shades Of Blue

PM this guy.
https://www.badcaps.net/forum/member.php?u=4727

He knows at least some of those MAC PSUs inside and out.

[godonr]

Re: Imac G5 20'' Recap... Shades Of Blue

Did you recap because of the blue screen? If so, you should know that with OSX, the blue screen indicates the launchd process is trying to run which includes basic system init tasks and fs consistency checks. This is all software related. Try booting in safe mode (shift key down while starting). If you're UNIX literate, there are ways to move associated startup files but usually it's easiest to reload the OS.

[Toasty]

Re: Imac G5 20'' Recap... Shades Of Blue

The original problem was the video, correct?
Are the 3 green LEDs on mainboard illuminated?
Does it chime on startup?

Video problems can (are known to) be directly related to these units bad PSU's. Which PSU do you have? Manufacturer & Apple p/n please...

Your PM stated Ltec caps in the PSU. Those are "replace on sight" in my book.

Toast

[cheebster]

Re: Imac G5 20'' Recap... Shades Of Blue

The original problem was the diff. shades of blue when booting.

It does chime on startup !

The 3 leds are green, i get the apple logo, then i get the loading thing that turns for a while, then a blue screen shifting from diff. shades. At this point,

The psu is a AC-BEL Apple P/N 614-0326 model API4PC46
Rev A

Thanks !!!

[Toasty]

Re: Imac G5 20'' Recap... Shades Of Blue

Have you tried doing a "safe boot"?

http://support.apple.com/kb/ht1564

[iheartbeets]

Re: Imac G5 20'' Recap... Shades Of Blue

Identical problem. 20" ALS model. Chime sounds every time. Every 20 or so times, the display actually powers up, shows the logo and circular waiting device, then goes to various shades of blue. Is this the PSU or the MOB? AHHHHHHH!!

Thanks,
Dustin

[badassbarber]

Re: Imac G5 20'' Recap... Shades Of Blue

i have a imac g5 20 inch als. when i start up the computer, everything starts up fine but the picture is all fuzzy and blury. all three leds on motherboard are solid green and the capacitors all look fine. i have reset the PRAM but no luck....any ideas what it could be?????james

[Toasty]

Re: Imac G5 20'' Recap... Shades Of Blue

From one of the other threads where a reply was made:

If you have AHT (AppleHardwareTest) DVD run it to verify video ram.

[marthyr]

Re: Imac G5 20'' Recap... Shades Of Blue

Hello,

I have seen that before on intel based motherboards.

Have you ear about gpu reballing?

That could be your problem

[PCBONEZ]

Re: Imac G5 20'' Recap... Shades Of Blue

You will see it on everything during the transition time to RoHS BGA.
Not even just IT equipment. Those were bad years to buy a fridge or a car.
[Or an airplane, or a satellite.]
-
Not to be confused with nVidia's problems.
nVidia had that problem and more.
.