Screen stays dark when booting up, iMac G5 20 EMC 2055

Screen stays dark when trying to startup. I hear the normal tone/chime sound, but that's it. Nothing else happens. I thought it was the hard drive, so I replaced it. Now when attempting to boot from CD, I get the same symptoms as before.

When I looked around inside, I noticed that 3 caps were bulging on top. One of these had some crispy brown stuff that had come out of it. The motherboard was replaced a couple of years ago, or so, at the Apple Store for free, to deal with this very issue. Now it looks like the same thing. I was told that the replacement board was "new old stock" meaning that it was manufactured around the same time and sat on the shelf all this time.

I'd like to replace these caps with new ones. I went to TheCapKing.com but they were out of stock. Sent them an inquiry. In the meantime, am I on the right track? Any advice? I'm pretty comfortable soldering the new caps in, I just want to know if I'm on the right track here or if I should be looking at something more. Any and all advice is welcome and greatly appreciated. Thank you.

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

2 Answers

Chosen Solution

Siegfried, yes absolutely. You will have to replace all your caps, regardless if this is the original error or not. If you do not fix those, you can not do any further trouble shooting. Hope this helps, good luck.

Was this answer helpful?

Score 1

Comments:

Thank you OldTurkey03. Do you have any suggestions as to where to get these? Who has high quality caps? Any and all info is greatly appreciated. Thanx again... :-)

by

I prefer to stay away from kits and order my caps separately. I do get most of my stuff from Mouser and/or Digikey and even so shipping is a bit high, I've never had any issues with their parts. I prefer Nichicon caps and go high on the temp. Never do I use anything less than 105C caps. Remember that for the values, you can go up but never down.

by

Thank you for this. I was wondering about the kits too. Good tip about going high on the temp. Your last line sounds like you're recommending against replacing the 1500's with the 1200's. This is the very reason I'm here in this forum. I would've never known "you can go up but never down". Should I replace the 120uF too? Since I'm ordering individually, I may as well, right? Let me know... Thanx again... :-)

by

Add a comment

Try Jim Warholic here: http://jimwarholic.com/apple

Was this answer helpful?

Score 1

Comments:

Thank you Mayer. I will be looking into this source you recommend. Do you have any other tips or advice? Thanx again... :-)

by

Mayer, Jim has a kit that is just one cap short of what I need. BadCaps.net has a kit that has all of the caps. However, I'm puzzled at what they say:

"this kit covers both generation 1 and 2 of the Apple G5 17" or 20" system. On the generation 2, the 1200uF caps replace the 1500uF 4v caps, as my 1500uF 8mm caps are too tall. 1200uF in place of 1500uF is within tolerance and has been thoroughly tested, no issues will come from this. The generation 1 G5 system will not use the 1200uF caps, and you will have 3 of the 1800uF caps left over, this is nothing to get alarmed about."

Your thoughts on the 1200uF replacing the 1500uF 4v caps?

Hmmm... I just took a second look at my board and I realized that I have 24) 1800uF 6.3v caps, 5) 1000uF 16v caps, 2) 1500uF 4v caps and 1) 120uF 16v cap. That last one was not a typo.

Neither of these kits have enough caps. Recommendations?

Anyone else reading this, please feel free to chime-in with anything helpful.

Thank you Mayer, and thank you all... :-)

by

I got a little mixed up in my previous post. Basically, my questions are: What you do think about the 1200/1500 swap? And, since none of the kits have the 120uF 16v caps, is it OK to leave these, or should I buy new ones and replace?

Thanx again... :-)

by

Add a comment

Add your answer

Siegfried will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 231