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Mac Pro completely dead after card exchange- need ideas

gugucom

gugucom

macrumors 68020
Original poster
May 21, 2009
2,136
2
Munich, Germany
I changed the slot bracket on my HD3870 card from one slot to two slot today. The graphics card had previously received a two slot fan cooler and at that opportunity I did not change the slot bracket because there was none in the kit. I managed to grab a two slot bracket with a grill and exchanged the slot bracket. The Mac was shut down in a regular way.

After re fitting the grafic card I tried to start the Mac Pro and there was absolutely no reaction when I pushed the power button. No light, no sound nothing at all. Fans are not starting and there is practically no reaction at all.

I have tried all sorts of trouble shooting and used a different socket for the mains cable. I have exchanged the grafics card and tried to start without grafics card. Nothing! I have turned the machine over to see if a metallic object may have fallen inside and short circuited my Mac. Nothing loose is in there.

I have a master/slave unit which switches all the peripherals with the Mac Pro. I can see from the change of LEDs that my Mac Pro takes power when I fit the power cable. So it should not be the mains cable, I would think. I have also eliminated the master/slave unit but nothing brings the Mac Pro back from death.

Is there any advise what I can do beyond taking it to the AASP? What kind of defect causes such weird boot failures?
 
Can you give more detail on what you tried with the computer?
I.e. PRAM reset, etc?

It might help people to give you some information, and keep from repeating the same things. ;)
 
I did not reset PRAM because it requires at least a rudimentary boot of the hardware which I don't get. I get absolutely nothing when I push the power button. I have given all the details of trouble shooting that I have done. It is a MacPro1,1 with OS X 10.5.7 with all the latest updates.
 
gugucom said:
I changed the slot bracket on my HD3870 card from one slot to two slot today. The graphics card had previously received a two slot fan cooler and at that opportunity I did not change the slot bracket because there was none in the kit. I managed to grab a two slot bracket with a grill and exchanged the slot bracket. The Mac was shut down in a regular way.

After re fitting the grafic card I tried to start the Mac Pro and there was absolutely no reaction when I pushed the power button. No light, no sound nothing at all. Fans are not starting and there is practically no reaction at all.

I have tried all sorts of trouble shooting and used a different socket for the mains cable. I have exchanged the grafics card and tried to start without grafics card. Nothing! I have turned the machine over to see if a metallic object may have fallen inside and short circuited my Mac. Nothing loose is in there.

I have a master/slave unit which switches all the peripherals with the Mac Pro. I can see from the change of LEDs that my Mac Pro takes power when I fit the power cable. So it should not be the mains cable, I would think. I have also eliminated the master/slave unit but nothing brings the Mac Pro back from death.

Is there any advise what I can do beyond taking it to the AASP? What kind of defect causes such weird boot failures?
Click to expand...

What happens if you take out the card? Does the Mac powerup? If so, then the cause of the system failure is due to the graphics card... check the card for possible shorts, maybe the backplate is causing a short somewhere??
 
Is there a motherboard reset button on the new Mac Pros? Also, have you tried unplugging it, taking out the battery on the motherboard, and holding power down for ~10s to reset the power management unit?
 
Try something really simple. Pull the power cord. Yank out the battery on the logic board, wait 30 seconds, then replace it and the power cord. Then see if it will boot. (Hard PRAM reset).

Also, do you have another graphics card to test with?
 
nanofrog said:
Try something really simple. Pull the power cord. Yank out the battery on the logic board, wait 30 seconds, then replace it and the power cord. Then see if it will boot. (Hard PRAM reset).

Also, do you have another graphics card to test with?
Click to expand...

I have pushed the hardware reset button.
I have tried another graphics card.
I have taken out the battery and waited 30 s. After battery refit and without a graphics card it is still dead as a door nail.
 
gugucom said:
I have tried another graphics card.
I have taken out the battery and waited 30 s. After battery refit and without a graphics card it is still dead as a door nail.
Click to expand...
This might seem odd, but are you sure the power outlet (wall) has power?
 
nanofrog said:
This might seem odd, but are you sure the power outlet (wall) has power?
Click to expand...

yes, I'm sure because other electric appliances work. I have also used a different outlet and a different power cord. I'm really out of options and am considering to remove the ventilation unit to check if the power button cable is damaged.
 
gugucom said:
yes, I'm sure because other electric appliances work. I have also used a different outlet and a different power cord. I'm really out of options and am considering to remove the ventilation unit to check if the power button cable is damaged.
Click to expand...
I had to ask. :p Your idea is definitely worth a look. :)

BTW, have you checked if the PCIe power cable come loose off the logic board?
 
gugucom said:
I have pushed the hardware reset button.
I have tried another graphics card.
I have taken out the battery and waited 30 s. After battery refit and without a graphics card it is still dead as a door nail.
Click to expand...

Wow!! That's really odd.
I wonder, could it be that the PSU is to blame?
 
slicecom said:
Did you properly ground yourself before you touched the internals?
Click to expand...
It's a possibility, but might be worth checking anything that can be thought of first. ;) Easier than having to take it in I think. :D

BTW, in an aluminum case, leave the power cord in, and the entire case is grounded. Keep one hand in contact with the case at all times, and before you touch any of the components, you won't have an electrostatic discharge. :)

Works well, particularly for people who don't have ESD wrist straps or workpads. ;)
 
Try to Hold.............. the Power Button, for say 30 sec.

If that fails, time to break out the Multi-Meter and check the Power Supply( I've blown 2 this week, damn heat:eek:)

I'd check the Power Button ribbon cable, on both ends, I'll see if I can Dig up the Pin out for the Logic Board Connector, an tell you what two pins to short, to make the PSU start.

Also, if the Power cable tests good, and is putting AC Power to the Circuit Board of the PSU, check the Fuse, then check the two leads that come from the Pins that short to trip the Power on, if all that tests Good, replace the PSU.

Unless, you have AppleCare, then just dig down and Call in, I think you need a repair.
 
Open up the PSU and check that any existing fuses are good. Check that all the cabling is seated properly too.

If you get no access light at button press it mean's the PSU is not supplying power to the motherboard. So the problem is before the MB in the "electrical pipeline" so to speak. :)
 
I had the fan unit out which is a mother of a job because it requires removal of the RAM case and the CPU housing. I had a SATA cable to the 2nd ODD fitted to the ODD SATA sockets on the logic board. The cable is long and I thought it might have pressed on the power button connector and damaged the cable to the power button. I checked this, but it is fine. Refitted everything and still no joy.

I had no funny noises on disconnect and I always discharge before I do anything internal.

I have two cables for PCIe on the logic board because I do experiment with 4870 which needs two power plugs. The cables look ok.

One more thing. I fitted a y-cable to the 2nd ODD drive power connector which was originally used to power the graphics card befor I got the right cable. I took this this old y-cable out in case it shorted something. I did not change something.
 
Tesselator said:
Open up the PSU and check that any existing fuses are good. Check all the cabling it seated properly too.

If you get no access light at button press it mean's the PSU is not supplying power to the motherboard. So the problem is before the MB in the "electrical pipeline" so to speak. :)
Click to expand...

Do you know how to get to the PSU?
 
gugucom said:
Do you know how to get to the PSU?
Click to expand...

Here's what the service manual for the 1,1 has to say on the topic:

service manual said:
Power Supply Verification
To power on, the computer’s logic board requires “trickle” power. If the system fails to power on,
first reset the SMC as described in this chapter. If the computer still doesn’t power on, follow the
procedure outlined below to determine whether the issue is related to the power supply.

Verify trickle power
Diagnostic LED 1 indicates the presence of trickle power required by the logic board to begin the
startup process.

LED 1 should be yellow when the DIAG_ LED button is pressed, indicating that trickle voltage is
present.

Verify Power Supply Is Providing Power
Diagnostic LED 7 indicates that the main power is OK and within regulation.

Plug in AC power cord, and press the power-on button on the front panel.

LED 7 should be green when the DIAG_ LED button is pressed, indicating that the main power is
OK and within regulation.
Click to expand...

For Apple's own disassembly steps (in 9 pages) see the PM I'm about to send you.
 
Thanks Tess for the PDF. I will go into the diagnostics checks now.

Trickle power is ok.
When I push diagnostic and the power button I do not get LED7. I will investigate from there.
 
You are right about that. Apple will take the URL down if you publish it. I need to find out why I do not have LED7.
 
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