IMac g3 not turning on

[Lololobolosse]

My imac g3 won't turn on before the crt was clicking and popping randomly and the imac was turning off randomly on time the crt makes a lot off sound and turning off and on rapidly and after that the imac was not turning on anymore

My imc is a dv se carbon

Sorry if i makes mistakes my English is note very good

 

[GiGaBiTe]

iMac G3s, especially the earlier slower models had high failure rates because of the capacitor plague. It was exacerbated by the fact the machine had no cooling other than poor convection, which resulted in the inside of the computer always being smokin' hot from the CRT.

If your machine is not turning on, and is making popping noises, you probably have bad capacitors and possibly also a failing flyback transformer. You'll have to disassemble the system to get a good look at the analog board, power supply and logic board, because they all have electrolytics that fail.

 

[Lololobolosse]

iMac G3s, especially the earlier slower models had high failure rates because of the capacitor plague. It was exacerbated by the fact the machine had no cooling other than poor convection, which resulted in the inside of the computer always being smokin' hot from the CRT.

If your machine is not turning on, and is making popping noises, you probably have bad capacitors and possibly also a failing flyback transformer. You'll have to disassemble the system to get a good look at the analog board, power supply and logic board, because they all have electrolytics that fail.

All the capacitors seems good and by reading other forum I really suspect the pav board

 

[GiGaBiTe]

Physical appearance of a capacitor is not a good indicator of its health. While physical signs like bloating or leaking will definitely tell you there is an issue with the capacitor, they can still fail and be very bad with no outward signs of failure.

 

[Timo W.]

Clicking and random shut-down means bad caps on the PSU board. You have nothing to lose by replacing them, so just try and see if it helps.

 

[Lololobolosse]

Clicking and random shut-down means bad caps on the PSU board. You have nothing to lose by replacing them, so just try and see if it helps.

I see on another forum when you try to turn on but shut down instantly and after that trying to push the power button do nothing and you have to unplug it and replug it and the imac does the same thing and their saying that the pav board.

 

[JonnyGators]

I'm new to these machines, not really a mac person, but I did recently pick one up, and have been reading up on them. Apparently the click/pop issue with screen blinking is a common issue with these, and it's generally attributed to the flyback transformer shorting out. Not saying there aren't capacitor issues - but that specific description - pops/clicks, accompanied by flicker on the screen, is the flyback transformer. From what I've read, it's a problem that can eventually escalate to the point that it's shorted out, and won't turn on anymore. That may have happened on yours. A way to test this would be to disconnect the display cable from the display port, and try powering it on with that disconnected. You won't have a display, but it should turn on and make the startup chime - if it's turning on with the display disconnected, but not with it connected, then that's probably your problem.

Also - my iMac is currently having occasional flyback pops, but separate from that it has an issue turning on at times. I think it's because the lithium ion battery on the board is dead, I've read that can make them act funny at times, replacement is on the way, we'll see if that fixes it. When it would first happen, I'd unplug/plug several times, disconnect the display - and no matter what, it wouldn't turn on. But after sitting for hours, overnight, it turns on again. Until it doesn't. But also, there's a PMU reset button on the board - pressing that once for a reset could clear an issue of it not turning on. I did run into the problem one day, and pressed the button, put it back together, plugged it in and hit the power button, turned right back on. I'm hoping the replacement battery will stabilize that, we'll see I suppose.

 

[Lololobolosse]

I'm new to these machines, not really a mac person, but I did recently pick one up, and have been reading up on them. Apparently the click/pop issue with screen blinking is a common issue with these, and it's generally attributed to the flyback transformer shorting out. Not saying there aren't capacitor issues - but that specific description - pops/clicks, accompanied by flicker on the screen, is the flyback transformer. From what I've read, it's a problem that can eventually escalate to the point that it's shorted out, and won't turn on anymore. That may have happened on yours. A way to test this would be to disconnect the display cable from the display port, and try powering it on with that disconnected. You won't have a display, but it should turn on and make the startup chime - if it's turning on with the display disconnected, but not with it connected, then that's probably your problem.

Also - my iMac is currently having occasional flyback pops, but separate from that it has an issue turning on at times. I think it's because the lithium ion battery on the board is dead, I've read that can make them act funny at times, replacement is on the way, we'll see if that fixes it. When it would first happen, I'd unplug/plug several times, disconnect the display - and no matter what, it wouldn't turn on. But after sitting for hours, overnight, it turns on again. Until it doesn't. But also, there's a PMU reset button on the board - pressing that once for a reset could clear an issue of it not turning on. I did run into the problem one day, and pressed the button, put it back together, plugged it in and hit the power button, turned right back on. I'm hoping the replacement battery will stabilize that, we'll see I suppose.

Where going to see I just buy a junk imac g3 for parts and it exactly the same model so it's going to be also the same analog board and pav board. I'm going to replace the pav board first because it's more easy but I have to wait for the delivery

 

[Lololobolosse]

Yes it's the flyback I tested the pav board in the junk imac but I think the crt of the junk imac didn't discharge and im a little scary to reopen it and take the analog board because there was not any sound of discharging when I turn it off did there's any thing to know if the crt correctly discharge?