02-04-2012, 07:38 PM

I have an iMac 17" 1.83 very early that some times will boot but after a while it bails. I thought the PS may be bad but it has no fat capacitors. Does someone know how to test one? This machine has no LED's. The ornge colors seem to be normal by the pictures I've seen.

02-07-2012, 06:41 PM

'that some times will boot but after a while it bails'

Do you mean it boots properly but after a while just cuts out?

If so it sounds like it's overheating?

02-07-2012, 08:24 PM

Originally Posted by Hammer Time

'that some times will boot but after a while it bails'

Do you mean it boots properly but after a while just cuts out?

If so it sounds like it's overheating?

Well now I can't get any response from it. I checked the plug on the PS that goes to the DC/DC board and I get 11.90v on the 2 gray wires and only .33v on the brown one. The caps look good on the PS and Logic board, I think the AC Line Filter is good otherwise I'd have no output on the PS. It's an early 2006 and has no LED's I'd like to have a pinout of the DC/DC board where it plugs to the Logic board.

02-08-2012, 08:04 AM

Apple Hardware Test would give you useful info.
Intel-based Macs: Using Apple Hardware Test

02-08-2012, 04:37 PM

Originally Posted by gsahli

Apple Hardware Test would give you useful info.
Intel-based Macs: Using Apple Hardware Test

Trouble with AHT or ASD is you have to get the machine to fire up to use them. I found if I put a frozen bag of spinach on the PS it will boot and stay up till I shut it down. The caps look good on both the logic board and PS I may change the 5 caps on the PS because I've nothing to loose doing that but I sure wish I could pinpoint the problem.

http://dl.dropbox.com/u/36728487/Pol...20sink%202.zip

02-08-2012, 05:22 PM

Have a look at this link:-


How do I test the power supply? - iMac Intel 17" - iFixit

02-08-2012, 06:38 PM

Originally Posted by harryb2448

Have a look at this link:-


How do I test the power supply? - iMac Intel 17" - iFixit

I saw this a few days ago but the instruction mentions a green wire and my PS has no green wire. This machine is very difficult to find any electrical info on it kinda matches a G5 iMac but it's an Intel and as far as I can tell prone to a lot of problems. I'm trying to find a pinout for the DC/DC board now because the PS produces 12v on the 2 gray wires and only .33 on the brown the output plug has 5 wires 2 black (grounds) and 2 gray with a lone brown.