Dead G5. Video included

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GEOS's picture
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Dead G5. Video included

So I got this 1.6GHz G5 for pretty cheap thinking it might be fixable. So far I've been wrong. It was sold to me without a power supply, so I was forced to buy one off ebay just to see if the thing had any life at all. I purchased a cheap, used, and "untested" power supply and installed it. When turned on, the G5 has almost no sign of life. Almost. The Power supply fans run, the HD spins up, and the red LED that alerts you of the air deflector not being in place lights up when its supposed to. Thats it though, No startup chime or anything else. I've made a short VIDEO of the G5 so you can better see what I'm talking about here. Any idea as to what the source of the problem could be? Logicboard? Processor? Power supply? Let me know if you guys have any advice.

madmax_2069's picture
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hummm your video link links b

oops double post

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hummm your video link links b

hummm your video link links back to www.applefritter.com. but it could be a number of things really. but it mostly sounds like a dead CPU r something to that matter. i know just about nothing about G5s cause i haven't owned one. but usually when there is power (HDD spins and lights light up) but no video or no sound it could be the CPU or the logic board or maybe a ram issue ( but usually if there is a ram issue you will still hear a start chime then a crash sound, or it will boot up but be very unstable).

have you tried replacing the Pram battery and try to reset the PMU 9 if it has one even)

i will let someone else chime in on this one

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Sorry about the link. here i

Sorry about the link. here is the correct one. http://www.youtube.com/watch?v=PNOKEaWdhyw Ya, Ive done PMU reset and replaced the battery.

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A few things to try

You may already have done these, but it doesn't hurt to check

• Do any of the status LEDs light up on the logic board? If so, can you tell which ones? I couldn't see any in the video.

• Remove all RAM and see if you get the "no RAM" beep. If you have PC3200 RAM that you know works in another machine (iMac G5, Power Mac G5), try swapping that in and see what difference there is in behavior (if any).

• Remove the graphics card and see if it boots up without it. Do the same for any other PCI cards installed (although I didn't notice any in the video).

• Remove the Airport and/or Bluetooth cards and see if that changes anything.

• Remove all drive cables from the logic board (IDE for optical drive, SATA for hard drives) and see if that makes any difference.

• Disconnect, then reseat, the cable for the front panel board (which contains the power button). If a friend has a working G5, maybe try swapping his front panel board into yours and see if there's any difference.

• I'm a certified Macintosh technician, with access to all the service manuals you can shake a stick at. I could look up the pinout for your particular power supply and tell you how to test it with a voltmeter. Could you PM your serial number to me so I can check that out?

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it could very well could be t

it could very well could be the wrong PSU for the G5.

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Re: A few things to try

cwsmith wrote:
You may already have done these, but it doesn't hurt to check

• Do any of the status LEDs light up on the logic board? If so, can you tell which ones? I couldn't see any in the video.

• Remove all RAM and see if you get the "no RAM" beep. If you have PC3200 RAM that you know works in another machine (iMac G5, Power Mac G5), try swapping that in and see what difference there is in behavior (if any).

• Remove the graphics card and see if it boots up without it. Do the same for any other PCI cards installed (although I didn't notice any in the video).

• Remove the Airport and/or Bluetooth cards and see if that changes anything.

• Remove all drive cables from the logic board (IDE for optical drive, SATA for hard drives) and see if that makes any difference.

• Disconnect, then reseat, the cable for the front panel board (which contains the power button). If a friend has a working G5, maybe try swapping his front panel board into yours and see if there's any difference.

• I'm a certified Macintosh technician, with access to all the service manuals you can shake a stick at. I could look up the pinout for your particular power supply and tell you how to test it with a voltmeter. Could you PM your serial number to me so I can check that out?

1. Nope, I don't get any LED's on the motherboard

2. I did try pulling all the RAM and never got any beeps or anything. This I thought was odd.

3. Tried without video card, no dice

4. I did try and remove the HD and Superdrive and it didn't help.

5. Whats the best way to remove those cables without breaking something? Do they have a clip? When I tugged on them they didn't wanna come loose.

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No LEDs -- Houston, we have a problem

If no LEDs then my next best guess would be the power supply. We should be getting an LED on the logic board that at least confirms we're getting a trickle charge.

At this point, your serial number (in a private message, not posted here in the thread where everyone can see it) would help me cross-reference the proper power supply and pinout for your particular G5. Also take note of the last 4 characters in the serial number printed on the power supply itself (under the aluminum cover plate) and send those to me too.

Most of the front panel board cables pull straight out from the logic board (with a little resistance), but there are a couple variations that have a small clip. The clip should be on the side facing away from the front panel, or away from the power supply, if there is a clip.

The SATA and IDE cables have no clips. They should pull straight out from the logic board.

Did you try removing Airport and/or Bluetooth cards yet?

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Re: No LEDs -- Houston, we have a problem

cwsmith wrote:
If no LEDs then my next best guess would be the power supply. We should be getting an LED on the logic board that at least confirms we're getting a trickle charge.

At this point, your serial number (in a private message, not posted here in the thread where everyone can see it) would help me cross-reference the proper power supply and pinout for your particular G5. Also take note of the last 4 characters in the serial number printed on the power supply itself (under the aluminum cover plate) and send those to me too.

Most of the front panel board cables pull straight out from the logic board (with a little resistance), but there are a couple variations that have a small clip. The clip should be on the side facing away from the front panel, or away from the power supply, if there is a clip.

The SATA and IDE cables have no clips. They should pull straight out from the logic board.

Did you try removing Airport and/or Bluetooth cards yet?

Sorry, I forgot to mention there aren't any Airport or bluetooth cards in it. I got the main power supply SN and Mac SN sent in a PM and what I believe the SN to the inside of the power supply is here: 03J15-00031. Also, is the little fuse in there supposed to be white?

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Making some headway ...

Okay, using the serial numbers you sent me, I was able to determine that you do in fact have the correct power supply for this machine. Cool.

Get yourself a voltmeter and set to the proper range to read 5V DC. Unplug the computer long enough to unplug the 22-pin power supply connector from the board, then plug it back in.

Looking at the connector face-to-face, with the clip facing down, pin 1 is in the top right-hand corner. Pins 2-11 work sequentially to your left. Pin 12 is under pin 1 in the bottom right-hand corner, and pins 13-24 work to the left.

Put the red lead of your voltmeter in Pin 1, and the black lead in Pin 23 to test for trickle charge. Your voltmeter should read 5V DC. If it doesn't the power supply is dead.

If you do get 5V across Pins 1 and 23, the problem is likely to be (in order of expense) the front panel board, the processor, or the logic board.

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Re: Making some headway ...

cwsmith wrote:
Okay, using the serial numbers you sent me, I was able to determine that you do in fact have the correct power supply for this machine. Cool.

Get yourself a voltmeter and set to the proper range to read 5V DC. Unplug the computer long enough to unplug the 22-pin power supply connector from the board, then plug it back in.

Looking at the connector face-to-face, with the clip facing down, pin 1 is in the top right-hand corner. Pins 2-11 work sequentially to your left. Pin 12 is under pin 1 in the bottom right-hand corner, and pins 13-24 work to the left.

Put the red lead of your voltmeter in Pin 1, and the black lead in Pin 23 to test for trickle charge. Your voltmeter should read 5V DC. If it doesn't the power supply is dead.

If you do get 5V across Pins 1 and 23, the problem is likely to be (in order of expense) the front panel board, the processor, or the logic board.

Okay, I'm getting 5v from that test. So it looks like the power supply is good then right?

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Re: Making some headway ...

GEOS wrote:
cwsmith wrote:
Okay, using the serial numbers you sent me, I was able to determine that you do in fact have the correct power supply for this machine. Cool.

Get yourself a voltmeter and set to the proper range to read 5V DC. Unplug the computer long enough to unplug the 22-pin power supply connector from the board, then plug it back in.

Looking at the connector face-to-face, with the clip facing down, pin 1 is in the top right-hand corner. Pins 2-11 work sequentially to your left. Pin 12 is under pin 1 in the bottom right-hand corner, and pins 13-24 work to the left.

Put the red lead of your voltmeter in Pin 1, and the black lead in Pin 23 to test for trickle charge. Your voltmeter should read 5V DC. If it doesn't the power supply is dead.

If you do get 5V across Pins 1 and 23, the problem is likely to be (in order of expense) the front panel board, the processor, or the logic board.

Okay, I'm getting 5v from that test. So it looks like the power supply is good then right?

sounds like the PSU is good, the only other things it can be is the front board, CPU, or logic board

the CPU or logic board is not going to be cheap. i dont know how much the front board will be but from what i have learned about being a Mac user is that parts for a Mac system have a high price tag on them (depending on where you get it from)

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Re: Making some headway ...

madmax_2069 wrote:

sounds like the PSU is good, the only other things it can be is the front board, CPU, or logic board

the CPU or logic board is not going to be cheap. i dont know how much the front board will be but from what i have learned about being a Mac user is that parts for a Mac system have a high price tag on them (depending on where you get it from)


Agreed about the high prices. This Saturday our local user group has the monthly "fix it" meeting and I'm gonna take the G5 with me. Hopefully somebody will have a G5 that I can talk to. Maybe swap a part or two? Oh well, maybe I can make some money back off it selling it as a parts machine. Thanks so much for your help!

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