iMac 233 Boot Issues

Someone recently gave me an iMac 233 with 192MB RAM, Tray CD-Rom. I added a 10GB HD. He said the system didn't work and I confirmed that when I tried to turn it on and got no response whatsoever. So I got into the system, unplugged everything and plugged it back in after I installed the HD. I turned the system on and I heard the boot chime and the screen flickered a few times as I could see it was booting OS 9 and then turned off, only to not turn back on. So I did it again, took the system apart, unplugged all visable plugs, the RAM, the battery, and put it all back together again. This time, I heard the boot chime, saw an image, no screen flicker though, then the system went off again. Is the battery bad?? That's the only thing that makes sense to me. I'd like to get an opinion before I go out and buy one. Also, are these 3.6v batteries available at Walmart. I saw some batteries that looked like they'd fit in the camera section. Thanks.

Could be the analog board acting up...


Edited to add:

The analog board is what controls the video card. I had a grape iMac whose analog board went gradually belly up and it refused to start up once it was completely gone. Do you have the CDs that came with the iMac? In the set you should find one that is called Hardware Test. Insert it in the optical drive and restart, holding down the C key. Run the test in Extended Mode if you can.

The system doesn't last long enough to run the Hardware Test. Once it goes out, I can't turn anything on until I open it up and unplug everything and start over, then I get one quick boot, then it goes out and I have to start over again. I don't get any lights or any response until I unplug everything. I'm thinking about unplugging one thing at a time and trying to power it on to see what the trigger is.

That indeed sounds like your best bet then.

I know that when my analog board was starting to go, it sounded like electrical zapping sounds, sometimes the screen would flicker, a couple of times the screen went like a horizontal white line then snapped out of it to resume normal behaviour. It was very weird.

Please keep us updated on what happens next. I am very intrigued by this problem of yours.

HMM, I tried unplugging the components one by one and was unable to get a response. Then I went back to my original method of unplugging everything I could see at the same time and still nothing. The only thing I did differently from before is there was about a day in between boot attempts when I was actually getting a response. Should I try buying a new battery to see if it helps?? Maybe the battery is getting enough juice by sitting to get the system to power on for a few seconds??? Are the batteries in the camera dept of walmart where I need to look for it??

This seems to be the battery you need.

Have you tried pushing the PMU?

Oh another thought! Did you try the old resetting the PRAM trick?

What's the PRAM trick?

Resetting the PRAM.

On startup, hold down those keys the Knowledge Base Article says and let the startup chime ring 5 times, then let go of the keys the startup will resume normally.

Okay, after waiting about an hour and reseting the PRAM, I got a response again. I didn't unplug anything this time. My guess is the battery doesn't have any juice and the longer I leave it alone, the more likely the battery has just enough juice to turn the system on, then it shuts back off again. Kind of like a car that runs out of gas, there are usually enough fumes to power the car on, only to turn right back off. I'm going to purchase another battery, then see what happens

Well, report back and let us know how it goes. Good luck. I hope the battery solves it for you. :girl:

Okay it's not the battery. I got a new one, plugged it in and same thing, system powered on for a few seconds and then off again. Probably the same thing you were describing earlier. Anyway inexpensive way to fix this??

Try pushing the PMU but that's about all the fixes I can think of.

I dunno try to see if the solders on the logic board are still good and if all seems well take it in for a repair estimate, the repair shop will know for sure what is acting up and how much it will cost to fix.

Too bad you can't run the Hardware Test.

The solders look okay. Yeah I wish I could get into the system long enough for a Hardware Test. This system is too old to get repaired, meaning not worth it. I may just hang onto it incase I need the parts.

For the record, when I unplug the video cable from the iMac and boot, the system turns on and stays on. Is that the flyback transmitter problem??