Imac G3 will not boot, gets mac chime seldomly

[JamesAvery22]

A friend threw me a dead Imac.

I plugged it in and hit the power and go the mac chime but nothing else and it just turned right back off. Screen never came on. Then if I hit the power button nothing happened.

If I leave it unplugged for awhile I can reproduce the same symptoms.

I believe, at the support desk I use to work at, we had the same model imac doing the same thing. He replaced the powersupply and it fixed it.

But searching for parts I saw that there are 3 main parts for the power supply.
The ps board, the ps Down Converter Board, and the Filter Power Supply.

Can anyone point me in the right direction? Thanks

James

[pncc]

A friend threw me a dead Imac.

I plugged it in and hit the power and go the mac chime but nothing else and it just turned right back off. Screen never came on. Then if I hit the power button nothing happened.

If I leave it unplugged for awhile I can reproduce the same symptoms.

I believe, at the support desk I use to work at, we had the same model imac doing the same thing. He replaced the powersupply and it fixed it.

But searching for parts I saw that there are 3 main parts for the power supply.
The ps board, the ps Down Converter Board, and the Filter Power Supply.

Can anyone point me in the right direction? Thanks

James

It could be any one of the three or a combination. Replace all three to be sure.

[JamesAvery22]

It could be any one of the three or a combination. Replace all three to be sure.


That sucks, could it be anything else too?

Trying to spend as little money on this as possible as its just coming out of my pocket.

Was wondering if I could just get it up and running

[Calliander]

A friend threw me a dead Imac.

I plugged it in and hit the power and go the mac chime but nothing else and it just turned right back off. Screen never came on. Then if I hit the power button nothing happened.

If I leave it unplugged for awhile I can reproduce the same symptoms.

I believe, at the support desk I use to work at, we had the same model imac doing the same thing. He replaced the powersupply and it fixed it.

But searching for parts I saw that there are 3 main parts for the power supply.
The ps board, the ps Down Converter Board, and the Filter Power Supply.

Can anyone point me in the right direction? Thanks

James

AASP's and the Apple Store have the training and the tools to verify which part(s) need to be replaced. Generally, this sounds like Power/Analog Video board or Logic board, but if you could elaborate a few things for me I might be able to at least give you advice on where to take it. :)

What type of iMac do you have - is the optical drive a tray-load or a slot-load model? If it's a tray-load, it's really not worth fixing. You could take it to an AASP and see if they will buy it off of you for parts. If it's a slot-load, there's a chance that the fix could be quick.

You say that you turn it on, you hear the chime, and then very shortly after the machine turns off. Is there any sort of noise accompanying the machine powering off? How long after the chime does it turn off? Does the power button light come on at all?

I hope we can get a working machine for you. :)

[JackRipper]

A friend threw me a dead Imac.

I plugged it in and hit the power and go the mac chime but nothing else and it just turned right back off. Screen never came on. Then if I hit the power button nothing happened.

If I leave it unplugged for awhile I can reproduce the same symptoms.


Which iMac G3 is it? I had the same thing happen to my 233 MHz Rev A, but I was using it when it died. The monitor popped and sizzled and then whenever I tried to turn it on afterwards it would either chime and shut off or nothing at all.

Luckily I had an old Apple monitor that I used with a Performa 6220CD because inside the iMac 233 is an old style monitor connector. I disconnected the internal monitor cable and plugged in the external and wa la! It booted and to this day it still works!

If you don't have an old Apple monitor (pre ADC) you should be able to find a Mac to VGA adapter cheap.

Let me know if you have questions, I can be more detailed.

[Calliander]

Which iMac G3 is it? I had the same thing happen to my 233 MHz Rev A, but I was using it when it died. The monitor popped and sizzled and then whenever I tried to turn it on afterwards it would either chime and shut off or nothing at all.

Luckily I had an old Apple monitor that I used with a Performa 6220CD because inside the iMac 233 is an old style monitor connector. I disconnected the internal monitor cable and plugged in the external and wa la! It booted and to this day it still works!

If you don't have an old Apple monitor (pre ADC) you should be able to find a Mac to VGA adapter cheap.

Let me know if you have questions, I can be more detailed.

Hehe. I was trying to avoid having him check that. But yeah, that's the flyback transformer. A lot of certified techs diagnose it "wrong." :)

I put "wrong" in quotes because, to my knowledge, it's not a part you can order - Apple has you order the whole PAV for it. Some places sell it used and an AASP will probably have a few older iMacs they can scavenge parts from.

[JamesAvery22]

AASP's and the Apple Store have the training and the tools to verify which part(s) need to be replaced. Generally, this sounds like Power/Analog Video board or Logic board, but if you could elaborate a few things for me I might be able to at least give you advice on where to take it. :)

What type of iMac do you have - is the optical drive a tray-load or a slot-load model? If it's a tray-load, it's really not worth fixing. You could take it to an AASP and see if they will buy it off of you for parts. If it's a slot-load, there's a chance that the fix could be quick.

You say that you turn it on, you hear the chime, and then very shortly after the machine turns off. Is there any sort of noise accompanying the machine powering off? How long after the chime does it turn off? Does the power button light come on at all?

I hope we can get a working machine for you. :)

Yep its a tray load :D Believe its a 266mhz Its not the "lifesaver" colored ones

Theres no noise after it powers off. Like a second after I hear the chime it turns off. The power button does turn on but goes out right after I hear the chime.

Im guessing there are just too many variables of my problem so it makes it a gamble to fix and I'll probably just spend to much trying to fix it?

[FattyMembrane]

you may want to check the clock-battery as well. it is probably too young to need a replacement but the symptoms sound similar to a dead clock battery.

[JamesAvery22]

you may want to check the clock-battery as well. it is probably too young to need a replacement but the symptoms sound similar to a dead clock battery.

Where is the clock battery?

[Judo]

Where is the clock battery?

The clock battery is called a PRAM battery and is located on the logic board (on a volt meter it should read around 3.6 volts. Any less and it should be replaced). To get to it you will have to pull out the logic board carrier out. A faulty battery can cause some strange things to happen, but usually only with really older computers, always worth checking out first though (cheap to replace and easy to test).

It sounds like either an analog board or a power board and less likely a logic board. You could try the following if you want.

FOLLOW THESE INSTRUCTIONS AT YOUR OWN RISK!

1. Find a safe place to put your computer screen face down.

2. Take off the the bottom plastic cover. Undo the screw at the top and yank the handle up and out.

3. OK. Now what you will see is the logic board carrier with either 3 or 4 cables plugged into it. 2 from the left (colored cables) and either 1 or two from the right (grey cables). Unplug the biggest cable coming from the right.

4. Plug the computer back in and turn it on. If the computer has power and stays on (the screen will stay blank becase you have just disconnected the analog board) the most likely cause of your problem will be the analog board. If it does the same as before it will most likely be the power board.

Have fun!

and tell us how you get along.

Nice idea Jackripper!

[Calliander]

If you're not comfortable doing those steps, see if you can find a local AASP that will check it out for you. At the very worst, you leave the machine with them - not like it's worth any money to you anyway. :)

[JamesAvery22]

If you're not comfortable doing those steps, see if you can find a local AASP that will check it out for you. At the very worst, you leave the machine with them - not like it's worth any money to you anyway. :)


Eh it was in pieces before I even posted here :D

I see what you are saying about testing the analog board. I'll check the pram battery then try hooking the it back up minus that one cable. Thanks

[JamesAvery22]

The pram battery is fine,

I'll check if its the analog board or PS later. Sorry for the old thread revival. Have had no time nor energy to work on this thing. Thnks again

James

[JamesAvery22]

The pram battery is fine,

I'll check if its the analog board or PS later. Sorry for the old thread revival. Have had no time nor energy to work on this thing. Thnks again

James

Uh which connector am I supposed to unplug?

http://filebox.vt.edu/users/jtorres/Pics/MacConnectors.jpg

[JackRipper]

Uh which connector am I supposed to unplug?


This one is the internal monitor connector. This is where I plugged in an external. If you don't have an old apple monitor you should be able to find a cheap (pre ADC) mac to vga adapter.

[JamesAvery22]

This one is the internal monitor connector. This is where I plugged in an external. If you don't have an old apple monitor you should be able to find a cheap (pre ADC) mac to vga adapter.


Unplugged it and still nothing. Ordered a new power board for 30$. Hopefully this will fix it :D Thanks for your help everyone I really appreciate it

[JackRipper]

Unplugged it and still nothing. Ordered a new power board for 30$. Hopefully this will fix it :D Thanks for your help everyone I really appreciate it

If you didn't plug in an external monitor it won't do anything. As far as I can tell the iMac will not boot without a monitor.

Anyway, I hope that power board does it for you.

[JamesAvery22]

If you didn't plug in an external monitor it won't do anything. As far as I can tell the iMac will not boot without a monitor.

Anyway, I hope that power board does it for you.


What Judo said was incorrect? Yeah I definitely hope a power board fixes it too :D

[JackRipper]

What Judo said was incorrect? Yeah I definitely hope a power board fixes it too :D

I'm not sure, he sounds like a tech, I'm just going off a previous experience with my iMac since it sounded like the same thing was happening to yours.

My iMac would not boot until I connected a working monitor to it. Maybe the power board will fix the internal monitor?

[JamesAvery22]

I'm not sure, he sounds like a tech, I'm just going off a previous experience with my iMac since it sounded like the same thing was happening to yours.

My iMac would not boot until I connected a working monitor to it. Maybe the power board will fix the internal monitor?


:Crossing my fingers: Got the PS this morning (came in yesterday afternoon but got home too late and they left it with my office, 3 day delivery via UPS ground, kudos) and I am going to try it when I get home.

[JamesAvery22]

:Crossing my fingers: Got the PS this morning (came in yesterday afternoon but got home too late and they left it with my office, 3 day delivery via UPS ground, kudos) and I am going to try it when I get home.


Eh looks like something else is wrong. It still does nothing when I press the power button...

I noticed when plugging the cables into the new PS board the brown cable that Im guessing just taps into the AC input doesnt have any markings on which way it goes. Pretty sure I put it in the right way, does this matter?

[blue&whiteman]

you have been at this so long james! don't give up now! I admire your stamina through this. most people would have scrapped it by now :)

[JamesAvery22]

you have been at this so long james! don't give up now! I admire your stamina through this. most people would have scrapped it by now :)


To be honest I haven't done much at all. Just took it apart once, test the pram battery, replaced the PS, and put it back together. It just took me like half a year cause work has been killer and I barely have enough energy to fall over onto the couch when I get home.


Now it isnt doing anything. Power button does nothing. Maybe I forgot to hook something back up?

There are the Three plugs on the PS, and four on the CPU/mobo unit, anything else??

bout to just ebay it for parts.

[windowsblowsass]

My 333 did this once oddly enough it was the hd ran diskwarrior from boot and repaired it try that prob wont work though i think my imacs hd was possesed every couple months wont boot right time to repair :o

[trainguy77]

I have heard people having simerlar problems. They fix it with the PMU button. If that model has a PMU reset button try that! It is on the mother board. Make certain the power cord is unpluged, and only press it once!wait ten seconds then pug the mac back in and turn it on. Hope this helps.

[JamesAvery22]

I have heard people having simerlar problems. They fix it with the PMU button. If that model has a PMU reset button try that! It is on the mother board. Make certain the power cord is unpluged, and only press it once!wait ten seconds then pug the mac back in and turn it on. Hope this helps.


Where is the PMU reset button?

[trainguy77]

i is some where on the mother board i have a pictures of it on a G4 tower. the button is labeled PMU reset. The button is not overly small. It should be easy to get at. I do not know for certain. You will need to open it up and take a look for it. Also if you find it, after pressing it the magazine, macworld, suggests you to hold down the cammand-option-p-r keys until it chimes twice. Hope this helps!

[JamesAvery22]

i is some where on the mother board i have a pictures of it on a G4 tower. the button is labeled PMU reset. The button is not overly small. It should be easy to get at. I do not know for certain. You will need to open it up and take a look for it. Also if you find it, after pressing it the magazine, macworld, suggests you to hold down the cammand-option-p-r keys until it chimes twice. Hope this helps!


Thanks, you sure a G3 Imac has that button?

[trainguy77]

i don't see why not? But i will check around to seeif it does.

[trainguy77]

here is a couple links:
http://forums.macrumors.com/archive/index.php/t-32991

http://http://forums.macrumors.com/archive/index.php/t-32991

It seems they have changed the name of the PMU(power managment unit)

[JamesAvery22]

here is a couple links:
http://forums.macrumors.com/archive/index.php/t-32991

http://http://forums.macrumors.com/archive/index.php/t-32991

It seems they have changed the name of the PMU(power managment unit)

I saw a button that I believe was labeled "CUDA Button"

Pressed that and I am back to square one :D It gives the chime now and shutsdown... Sooo atleast the two powersupplies are good :D

[JackRipper]

I saw a button that I believe was labeled "CUDA Button"

Pressed that and I am back to square one :D It gives the chime now and shutsdown... Sooo atleast the two powersupplies are good :D


I hate to keep bringing this up, but I think you're problem is the internal monitor. I have an old 15 inch Apple monitor that can connect to the iMac's internal connector ( the one that I pointed out to you in the picture ). If you'll pay for shipping I'll give it to you as I'm certain it will allow the iMac to boot.

[JamesAvery22]

I hate to keep bringing this up, but I think you're problem is the internal monitor. I have an old 15 inch Apple monitor that can connect to the iMac's internal connector ( the one that I pointed out to you in the picture ). If you'll pay for shipping I'll give it to you as I'm certain it will allow the iMac to boot.


Thats very generous of you and I really appreciate it but I dont think I want to replace anything else on this imac, I dont think it will be cheap to replace any of the monitor parts correct?

If thats the case Im just going to ebay it for parts. The problem is I want to zero the hd before I sell it, else I guess I wont sell it with the harddrive as I dont want who ever I sell it to, to have access to my buddies files/emails/etc.
Would a mac store charge me to just zero a drive for me? Could I put it in a PC and do that?

edit---
well on second thought, how much would you charge me for that monitor + shipping? I am in mclean VA, If that would allow me to boot it would atleast allow me to get my buddies files off the computer and then it would be worth it.

[JackRipper]

Thats very generous of you and I really appreciate it but I dont think I want to replace anything else on this imac, I dont think it will be cheap to replace any of the monitor parts correct?

If thats the case Im just going to ebay it for parts. The problem is I want to zero the hd before I sell it, else I guess I wont sell it with the harddrive as I dont want who ever I sell it to, to have access to my buddies files/emails/etc.
Would a mac store charge me to just zero a drive for me? Could I put it in a PC and do that?

No problem, I'm not using it any more and just thought I'd donate it to a fellow iMac owner with the same problem.

The iMac uses a standard IDE/ATA drive ( the same a PC's ) so you should be able to connect it to a PC and zero it out. It's kind of a pain to remove though ( it's directly below the cd rom drive, which is also a little tricky to remove ).

I don't guess you live in Virginia, USA, do you? If so maybe we could meet half-way somewhere. If not, good luck zeroing the hard drive and selling it.

[JackRipper]

edit---
well on second thought, how much would you charge me for that monitor + shipping? I am in mclean VA, If that would allow me to boot it would atleast allow me to get my buddies files off the computer and then it would be worth it.

The monitor would be free. I live in Culpeper, I don't think that's far from you. Would you like to meet somewhere so I can give it to you?

[JamesAvery22]

The monitor would be free. I live in Culpeper, I don't think that's far from you. Would you like to meet somewhere so I can give it to you?

::googling culpeper:: Im horrible with cities and locations :D

Bout an hour away. Id be willing to meet half way. Shoot me an email and we can discuss a meeting place. my email is mailcall(nospizam)@vt.edu withouth the (nospizam). Thanks again Jack

Edit---

Oh yeah once I get the monitor how should I go about disconnecting the Monitor from the powersupply? Is that the brown cable thats just two large leads that just taps into the A/C in? Or should I not do that at all?

[JackRipper]

::googling culpeper:: Im horrible with cities and locations :D

Bout an hour away. Id be willing to meet half way. Shoot me an email and we can discuss a meeting place. my email is mailcall(nospizam)@vt.edu withouth the (nospizam). Thanks again Jack

Edit---

Oh yeah once I get the monitor how should I go about disconnecting the Monitor from the powersupply? Is that the brown cable thats just two large leads that just taps into the A/C in? Or should I not do that at all?

ok, great. I'm getting the email together now.

No, disconnect this one and plug the external monitor into it.

[JamesAvery22]

ok, great. I'm getting the email together now.

No, disconnect this one and plug the external monitor into it.


Thanks, I cant check my email at work but I'll be sure to email you back as soon as I get home.

So I should leave the monitor plugged into the PS? that couldnt cause any problems?

[JackRipper]

Thanks, I cant check my email at work but I'll be sure to email you back as soon as I get home.

So I should leave the monitor plugged into the PS? that couldnt cause any problems?

Yeah, just leave it plugged in, all I did was unplug the video cable and plug the external into the internal connector.

[JackRipper]

Did you get the email I sent yesterday? I didn't get a response.

[JamesAvery22]

Did you get the email I sent yesterday? I didn't get a response.


No I dont think so. Was just about to post the same thing. Mind sending it again? Hoping my smtp server isnt on the blink =(

[JackRipper]

No I dont think so. Was just about to post the same thing. Mind sending it again? Hoping my smtp server isnt on the blink =(

I'm just going to ask here, since I get answers faster :). The place you suggested is fine and I prefer to do it tomorrow, if that works for you. I'll be visting relatives in that area then.

What do you think?

[JackRipper]

You must have logged off, I resent the email anyway, but I think by then it will be too late ( if you get it at all ). Oh well, maybe next week.

[JamesAvery22]

You must have logged off, I resent the email anyway, but I think by then it will be too late ( if you get it at all ). Oh well, maybe next week.

Lol we keep missing each other. I appologize for missing emails. Work and other things have been killin me. Just let me know whenever is convenient for you. Thanks again

James

Edit---

Now that I think about it, of course if you are willing, how much would it be to ship it freight? Absolute cheapest way possible? I could just send you a paypal payment for shipping. With my bad schedule that might be the best way =\

[JackRipper]

Lol we keep missing each other. I appologize for missing emails. Work and other things have been killin me. Just let me know whenever is convenient for you. Thanks again

James

Yeah, I hear you. It's been rough for me too. Let's shoot for this weekend. I think it will be easier to arrange over the phone. I'll email my home number so maybe we can talk tonight.

[SongSeeker]

I just came new to the thread. It sounds to me like you have a bad analog board (the one on the other side from the power board). It's the board that contains the flyback. Here's a site that'll tell you more than you may have wanted to know about the issue--including how to replace the faulty flyback yourself, not the entire board (some soldering required).

http://www.macopz.com/columns/imacrepair/

[JamesAvery22]

Yeah, I hear you. It's been rough for me too. Let's shoot for this weekend. I think it will be easier to arrange over the phone. I'll email my home number so maybe we can talk tonight.

Any chance you got a quote for shipping yet? =)

[JackRipper]

Any chance you got a quote for shipping yet? =)

Sorry, not yet. I'll throw it on the scale tonight and call in the morning for a quote.