Old, Forgotten SL iMac G3 Problem...

[CC_333]

XBHS1997's thread reminded me of my Tangerine SL iMac, which has had a most peculiar problem since new: the screen will flicker and shink upwards from the bottom sometimes, and if it goes far enough, the display will "blink out", and the machine will die. A few good slaps on the top will usually fix it. What could cause that? I've always just assumed that it was a loose connector somewhere.

Also, it is probably due for a PAV board recap, even though it worked fine last I used it (aside from the occasional manifestation of the above issue), as it sounds like it's a problem.

c

 

[EvilCapitalist]

I had a CRT Studio Display that had that exact problem and the answer I always heard was the flyback transformer was on the way out.

 

[CC_333]

But it was doing this since new?

If I weren't so young and ignorant (I was like 10 or 11), it was probably one of those things the warranty would've covered.

Be that as it may, it's still here, and last I knew, it was still working.

Oh, well. I'll have to fix it up someday, with new plastics and stuff (could the inner bezels from a newer, hopefully less disintegrated iMac G3 be used on this old 1999 model of mine?)

c

 

[XBHS1997]

I'm beginning to think that pretty much every CRT or startup problem is related to this PAV board. I've been warned about taking that out, but if it needs a recap (This should be possible?), it needs to be done anyway.

Not quite sure and I don't know if any major modifications have been made to the case through the Slot Loader production, but I thought(!) that the older Slot Loaders had less fragile bezels. Could be wrong though. Probably their condition is more related to the iMacs "life experience" than its age though. Some seem to be quite bendable, while others have screw covers that will just snap off in pieces. For example my Blue Dalmatian has a broken inner power button (same material as the bezel, it seems), I've not figured out yet how to fix this, because this part is needed to physically "connect" the external power button and the actual button inside. And my Flower Power has a badly damaged inner bezel, but no outer case damage... But the others still look quite in shape, at least from the outside.

(Btw the early DV Slot Loaders are my favourite one, I'll need to get them all. I have the 350 Mhz Blueberry and the DV SE 400 Mhz Graphite, but no DV of the first Slot Loading gen. Need to get these, Sage and a Bondi Blue, then I'll have all colours. )

Nicolas

 

[EvilCapitalist]

But it was doing this since new?

That I can't say since I only owned it for about a year and in 2005 schools around where I lived at the time were tossing them left and right.

Oh, well. I'll have to fix it up someday, with new plastics and stuff (could the inner bezels from a newer, hopefully less disintegrated iMac G3 be used on this old 1999 model of mine?

So long as you're doing like-for-like (tray for tray, slot for slot) I think they're interchangeable.  I almost want to say the internal CRT plastics in the iMacs are "Spindler's Revenge" since I've seen a whole lot of them that are just splintered to pieces.  One of them was so bad the CRT "adjusted" like it did in the Monitor //, though the tray loaders seem to be stronger than the slot loaders.

 

[Schmoburger]

My Graphite DV SE has the inner bezels from a very early (99?) DV so yes, i can verify the slotload bezels are 100% interchangable with each other. Thre is a difference if I recall in the position of the CPU heatsink in the metal chassis itself which makes it very ill advised to put 350/400/450 logic boards in 500/600/700 chassis and vice versa. And well, my experience has it at least that the later ones actually have worse plastics than the early ones. Obviously this is dependant just as much on the environment and manufacturing variations from batch to batch, but well... there seem to be plenty of early iMac's have come through my hands with nice pliable grey plastic inner bezels, even from non-airconditioned mid-2000's public school computer labs etc. Meanwhile I've never come across a 500 or 600 mhz machine with good plastic... some are better than others but all tend to be varying degrees of brittle and beginning to yellow. Every single one.

 

[techknight]

My old iMac 500Mhz machine did the very exact same thing. And I will tell you this: it is NOT a solder joint. its actually a bond wire coming loose on one of the legs of the main chopper transistor in the power supply of the analog board. 

And the Opto-isolator can do this as well. 

 

[XBHS1997]

Asking again if anybody has experience with repairing/recapping these PSUs?

 

[360alaska]

Funny Story, as kid in 2002 I found a blueberry 266 Imac tray load in a dumpster. I was just walking by and there it was, I carried it home and found that besides the CD-ROM it did work. The CD-ROM looked like somebody had attempted to pry it open (probably because they did not understand that they had to drag the cd into the trash in the finder.) Anyways, I had it for many years but one day It just wouldn't boot up. It would chime, but when it came time to fire up the monitor it would just shut off. I had opened it up before to upgrade the RAM and I noticed that a certain cable looked like a monitor cable and sure enough, it was. I connected a vga adapter and connected an external monitor and I did operate it like that for many more years...