Problem with MDD FW800 and Studio Display

[Jaycen]

I have searched the web and looked in many forums and haven't found a problem remotely like the one I’m having.

The problem is with my MMD FW800. It’s a dual processor running at 1.25 GHz with two 80 GB hard drives. The first hard drive has Tiger installed and the second has Leopard. The problem is that when I have a studio display connected it will either not boot or boot into open firmware. Also with the studio display connected, the computer will give a long tone before the initial bong you get when starting up.

If I connect a normal monitor, I’m connecting a Compaq flat panel., the computer boots normally with no problems whatsoever.

I don’t have any USB connections to the monitor, though I have a wireless mouse connected to the keyboard USB.

Things I have tried:

Resetting the Pram

resetting the nvram

resetting open firmware

Any ideas would e greatly appreciated. Oh one other thing. When i first started using the studio display everything worked with no problems. This not booting or booting into Open firmware came on suddenly.

 

[Byrd]

Just to clarify, what is the studio display? It's not an ADC model, is it?

 

[Jaycen]

Yes the studio display is the first monitor that apple used ADC.

 

[Byrd]

Noting that the MDDs have terribly unreliable power supplies (that can get progressively worse over time with erratic voltages), it could be a possibility that the ADC display, drawing all its power from the MDD, makes it fall over when plugged in. The other thing is the graphics card - which model is it? Can you try another ADC graphics card? Remember that the Apple AGP graphics cards have special connector providing +28V for ADC power, which a standard VGA display does not use - this is the difference.

I'd try disconnecting things like your HDs, optical drive, remove any additional PCI cards, external peripherals etc. to lower the load on the power supply - then plug your ADC display in. Also try blasting any dust out of the AGP slot, and clean the connectors on your graphics card (you can use an eraser).

Interestingly, I found this link while researching ADC which details modding the display for standard DVI signal + use an external 24V power brick:

http://forums.bit-tech.net/showthread.php?t=188336

JB

 

[Jaycen]

DId the suggested clean out and it seemed to fix the problem but then it came back. However I did manage to get some more info when the computer booted normally. Apparently the problem started after the computer had a Kernel Panic.

So I'm going to get a different Graphics card and see if that fixes the problem. If not I'll take a closer look at the power supply.

I'll let you know how it all turns out.