imac G3 startup problem - PRAM?

[tanaquil]

Long story, bear with me. I am trying to figure out whether I'm looking at a simple fix (PRAM battery replacement) or a complete take-apart.

I recently got a blueberry tray-loading iMac to complete my collection of tray-loading fruit colors (I fully intend to arrange them in a sunflower).

I suggested to the seller on ebay to "wrap it well and ship it resting on its face/CRT down," remembering the unfortunate UPS thread. Apparently the seller interpreted this to mean "resting face down on a paper-thin sheet of foam and throwing some bubble wrap in there." It is an absolute miracle that the computer didn't arrive shattered into a million pieces.

When I got it out, the only visible "damage" was a slightly dislodged panel of colored plastic. I couldn't wiggle it back in without taking things apart, so I figured this was a good opportunity to learn to disassemble a G3 imac. When I got it apart, I found a bit more damage (denting, a broken plastic tab, etc) inside the corner where the dislodged plastic was, but everything looked pretty functional and I managed to get it apart and smoothly back together again. Right now, the computer looks good except that the lower part with the blue speaker grilles on the front isn't quite flush on one side. I'm too tired to take it apart again to see if I can fix whatever is causing that.

Anyway, the main point of this post is that when I finally plugged it in and tried to start it up, the power button lights and it sounds a healthy chime, but the power then shuts itself off a second or two later. The screen never lights up.

I removed the PRAM battery while I was in there (Maxell!!). I'm waiting on the arrival of more fresh PRAM batteries, but would the absence of a PRAM battery cause this symptom? Or am I looking at some more mysterious damage on the analog/power supply board? 

If it's relevant, I found a couple of small pieces of brown plastic (one about the size of a dime, the other much smaller) rattling around inside when I opened it. I didn't get as far as taking the EFI shield off, so I don't know if there might be a broken part somewhere inside there.

The hard drive has also been removed, but that wouldn't cause failure to power to boot screen - would it?

Suggestions welcome!

 

[bibilit]

If you can hear the Chime it's a good point

If you have several units, try to swap boards...

 

[tanaquil]

Swap boards: oh, that's a good idea. I will try that once I have more feedback on this thread. I now have five (!) tray-loading fruit imacs and three (!) slot-loading imacs (blueberry, indigo and ruby). I have problems - both storage and mental.

As far as I know, all the other units work - at least, they were reported working when I picked them up from their respective sellers, although I haven't had the time to do full testing.

Anyone know if the slot-loading imac has the same analog/power board as the tray loader? 

 

[Nathan]

It could be the PRAM battery, I know I initially had some issues with my Bondi iMac G3 not starting right (as in no start/video at all) until it had been plugged in for a while that seemed to go away when I replaced that battery. If you replace the battery (good common sense at this point unless you know it was replaced recently) and it starts up fine then you'll know with reasonable certainty.

I wouldn't worry about some cracks and broken plastic if I were you. Unless you were hoping to collect it for it's resale value in the future then you were bound to have some brittle/broken plastic eventually and you'd have to live with that anyway. I know mine has a few minor bits of damage and an average number of scratches.

 
That's a nice collection by the way. We had these iMacs in my elementary school and they looked cool and they're fairly distinctive.  I've always wanted one of the indigo ones. It's a really pretty blue color and has the advantage of a slot loading drive and in some cases, the firewire ports (not that I have any firewire devices). Unfortunately since they're a fair bit faster (400-500 mhz usu.), can use more ram, and are able to run some version of OS X, they tend to still cost a fair bit even when you ignore the shipping.

P.S.

Sorry the person shipping wasn't more careful. The only thing that I've had shipped that I was really concerned about was my Apple IIe + Monitor which I bought on eBay. There was so much packing material in that box (which was easily 3-4 feet square) that I had to dig around a little to actually find the contents. Not that a CRT monitor of any sort is easily missed. I've generally had good luck with the people packing stuff, things usually arrive packed to something of an excess. I had piles of bubble wrap for a while in the past.

 

[tanaquil]

Thanks! PRAM batteries are in the mail, so that's the first thing I'll try.

I'm not worried about broken plastic on the inside except to the extent that it made me worry about the possibility of other broken stuff I couldn't see. Considering how it was packed, I feel grateful that the outside looks as good as it does.

Worst case, I can still use this unit to show off the fruit colors even if I never get it to start. But it will bother me if I don't at least try to get it working.

I can't believe Apple was still using those Maxell batteries in 1999!

 

[Nathan]

If you've got a long wait for delivery you might leave it plugged in for a few days and try again. I don't know if no battery is any different from a basically dead battery though,

 

[tanaquil]

Good news and bad news: I cleaned up the second most recent of my fruit iMacs, and it started up just fine both before and after cleaning, the latter after the dreaded dead Maxell had been removed. So apparently, the problem with my first Mac can't be traced to the missing PRAM battery. Unless it's a hard drive issue after all, I am back to contemplating an analog/power supply problem.

That was the bad. The good is that my second fruit Mac is clean now and still boots. I have never seen a computer in such disgusting shape that was actually able to run. It looked like someone had spilled a coke that ran down and pooled in the clear base. *shudder*

 

[Nathan]

I'd still say you try a new PRAM battery. If you have one that you aren't worried about loss of whatever data it's backing you could swap it from that mac into this one and see if anything changes.

If it was just a hard drive problem then you would know by now. A faulty/damaged hard drive or one without an operating system shouldn't prevent the iMac from starting. I doubt that an absent drive would be a problem since I think all the startup stuff prior to executing the OS is stored in ROM. In that case it should start and you should see a folder with a flashing question mark indicating that it can't find something to start/run. If, as you said earlier, you heard the expected startup chime then something else is the problem probably.

Unless you're a hundred percent sure about it, maybe you should open it up and check to see that all of the internal cabling is securely seated. Maybe something is loose from all the movement in shipping.

 

[belgaonkar]

In terms of iMac shipping, I found its best to either ship in the original box, or have FedEx pack it. The real killer is the inside face plate (usually a beige color) snaps into a million pieces.

The soldering on an iMac G3's Power supply Board is absolute trash, the ends are terribly cut, and it looks like it was a backyard project! I would try recapping the power supply, a cap may have fallen due to shipping.

Maybe first try a new PRAM battery, if that doesn't work try re capping it.

I have never heard of the "explosive PRAM" battery syndrome on an iMac, Im pretty sure they fixed that issue. Well maybe Im just lucky, none of my iMac have had that issue.