Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Desktops > Four Duff iMac G4s—Help Greatly Appreciated!

Four Duff iMac G4s—Help Greatly Appreciated!
Thread Tools
Koralatov
Senior User
Join Date: Jun 2007
Location: Aberdeen, UK
Status: Offline
Reply With Quote
Mar 20, 2008, 03:36 PM
 
So, I bought a bunch of (non-functional) Macs off eBay with the intent of fixing them and selling them on at a profit. I (somewhat stupidly) convinced myself that it would just be a case of a quick PMU reset and they’d all be working fine. However, I’ve tried the four iMac G4s, and it hasn’t entirely solved the problem. Three of them now boot, which is a definite improvement, but none get very far.

One of them is still stone dead; I have no idea what’s wrong with it. It just doesn’t power on at all. I haven’t opened it up to see, but I will do that somewhere down the line to try and diagnose the problem, once I’ve investigated (and hopefully fixed) the less-bricked ones.

One of the four powers on, but there’s no ‘bong’. It’s definitely on though—the fan in the bubble is going.

The finaltwo power on and ‘bong’, but stick at a plain white screen. I’ve put in a Tiger disc, held ‘C’ at boot, and it spins up the drive, but nothing appears on screen.

Overall, I’ve only spent about an hour looking at them—basically preliminary testing. Does anyone have any ideas what might be wrong with them and, more importantly, how to fix them? I’m not willing to spend too much money on them, and as such an Apple Service Centre is totally out of the question. That said, I’m not averse to getting my hands mucky by cracking them open.

Any help would be very much appreciated!
     
longwood
Junior Member
Join Date: May 2005
Location: Portland, OR
Status: Offline
Reply With Quote
Mar 20, 2008, 04:18 PM
 
i would assume that the no chime one has bad PSU or hard drive. As far the other two, I'm guessing a possible memory (ram and/or hard drive) and/or video card. Sorry not too helpful, but until you try somethings it will be hard to pinpoint the problem. Good Luck!
iPhone 4: [32GB]
iPad 2: [16GB | WiFi]
MacBook: [13" | 2.4Ghz | 4GB | 500GB]
     
Koralatov  (op)
Senior User
Join Date: Jun 2007
Location: Aberdeen, UK
Status: Offline
Reply With Quote
Mar 20, 2008, 04:30 PM
 
Originally Posted by longwood View Post
i would assume that the no chime one has bad PSU or hard drive. As far the other two, I'm guessing a possible memory (ram and/or hard drive) and/or video card. Sorry not too helpful, but until you try somethings it will be hard to pinpoint the problem. Good Luck!
Thanks for the input. Any idea what kind of tests I should run to try and pinpoint what’s gone bad? I’m about to go boot one of the kinda-functioning ones into Target Disk mode to see if it turns up anything.

Edit: So far, I got one of them to boot up fine in TD mode. It turns out that there was no OS on the drive at all, and that it was in need of reformatting. I’ve installed Tiger on it now, and I’m currently updating it to 10.4.11. However, instead of the Target Disk image appearing on the screen, it just stays totally white.

I spoke to former MacNN member shifuimam, and she suspects that the problem is the display cable—from the symptoms I described, it’s obvious that the display is getting power, but likely isn’t getting data. As such, I think my next action will be to get a replacement display cable for it. The only problem is, I can’t seem to find one. I’ve tried googling it. Does anyone know what the part number is or, better yet, a site I can get one from? Thanks!
( Last edited by Koralatov; Mar 20, 2008 at 06:36 PM. )
     
longwood
Junior Member
Join Date: May 2005
Location: Portland, OR
Status: Offline
Reply With Quote
Mar 20, 2008, 08:04 PM
 
Originally Posted by Koralatov View Post
TSo far, I got one of them to boot up fine in TD mode. It turns out that there was no OS on the drive at all, and that it was in need of reformatting. I’ve installed Tiger on it now, and I’m currently updating it to 10.4.11. However, instead of the Target Disk image appearing on the screen, it just stays totally white.
So it booted up in TD mode and then you reformatted the internal and then installed Tiger from a disc? Or you just tried to copy everything over to the internal hard drive? If you did the later, did you use something like SuperDuper or Carbon Copy Cloner?

As such, I think my next action will be to get a replacement display cable for it. The only problem is, I can’t seem to find one. I’ve tried googling it. Does anyone know what the part number is or, better yet, a site I can get one from? Thanks!
You can buy a mini-VGA cable that you can plug into the iMac and attach an external monitor or TV - that may be a cheaper route and less labor intensive. Something like this or like this
iPhone 4: [32GB]
iPad 2: [16GB | WiFi]
MacBook: [13" | 2.4Ghz | 4GB | 500GB]
     
Eriamjh
Addicted to MacNN
Join Date: Oct 2001
Location: BFE
Status: Offline
Reply With Quote
Mar 20, 2008, 08:37 PM
 
Cut off the head and sell it?

Using an external mini-VGA cable will at least tell if you it is the display.
If you have ram, HDs, etc., you can start swapping things. But if there is no bong, you are pretty screwed. Swapping mobos to test PSU is tough work.

I'm a bird. I am the 1% (of pets).
     
Koralatov  (op)
Senior User
Join Date: Jun 2007
Location: Aberdeen, UK
Status: Offline
Reply With Quote
Mar 21, 2008, 03:46 AM
 
Originally Posted by longwood View Post
So it booted up in TD mode and then you reformatted the internal and then installed Tiger from a disc? Or you just tried to copy everything over to the internal hard drive? If you did the later, did you use something like SuperDuper or Carbon Copy Cloner?
I reinstalled everything from scratch, and ran Software Update. As it goes, everything is working fine now—except the screen is still blank white. Normally, I would use Carbon Copy Cloner if I’d wanted to make an exact duplicate of something. (It’s saved my bacon on more than one occasion.)

You can buy a mini-VGA cable that you can plug into the iMac and attach an external monitor or TV - that may be a cheaper route and less labor intensive.
I was planning on getting one of those for my own (20") iMac, and then using it with Screen Spanning Doctor, so I might just buy one ahead of schedule and use it to test the semi-functioning iMacs. That route is definitely less labour intensive, but if I can get the right display cable for cheap, I’d definitely like to get the built-in display working again.

Originally Posted by Eriamjh View Post
Cut off the head and sell it?
That’s kind of a last resort; I’d really rather avoid doing it that way if I could. As I said above, if I can find the display cable, I’ll try going that route on the two that appear to have functioning screens. The other two are trickier—neither bongs, but one of them does come on. I might just be forced to part those ones out on a sold-as-seen basis to try and get some of my cash back. Either that or scavenge them for components (such as the display cable) in the hopes of getting the other two working properly.

Thanks for the replies everyone. If anyone thinks of anything else that may be of help, please chip in!
     
   
Thread Tools
 
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Top
Privacy Policy
All times are GMT -4. The time now is 12:02 PM.
All contents of these forums © 1995-2017 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2017, Jelsoft Enterprises Ltd.,