Parts Pismo - trying to get working again...

[J English Smith]

Hey 68k/PPC experts, I need a "next thing to check out" point in the right direction...

Bought a parts Pismo to add to my fleet. It was missing the HD, processor guard and CD. Since I have many other Pismos, I thought I might be able to get this one going again and only have to pop for a new processor guard.

I swapped a used 6GB hard drive in (I am not sure 100% if this one is working), swapped 400 mhz cards to a known working one, installed RAM and disconnected the backup battery.

I get a startup chime and then it comes up to a white screen only.

Does that indicate some type of main board fault? What can I try next to try and isolate the problem? Swap in a different hard drive, or try to boot from a 10.4 OS disk in the CD drive?

I have tried the power reset using the back button too. No change. I also tried reconnecting the PRAM battery. No change.

WWYD?

 

[J English Smith]

I think I've got it...disconnected the HD and now I do get the ? folder on screen. SO it looks like this HD is bum and I just need to get a new drive plugged in there and re-loaded...

 

[Bunsen]

That's probably your best bet. There's a small chance that it could be a power issue, in that the power circuitry doesn't have enough oomph to run the motherboard, screen and hard drive, but that's pure speculation on my part.

Just for fun, you could try booting it from a CD, or from an external (and thus externally powered) SCSI HD.

 

[J English Smith]

Update - I fear it might be a mainboard issue after all.

• I tried a total swap of changeable parts - known working hard drive, 400mhz CPU, RAM, airport card.
  Can start an installation from CD, but it sees no destination drive.
  When I try to force a boot from CD, it goes back to the installation process.
  In system profiler, it does not see any ATA drive, even though the known working HD is connected.
  When I startup with no CD in the drive, I get a folder icon that flashes between a ? mark and the Apple happy face icon.
  I do get chime at startup.
  I have tried the reset button, plugging and unplugging the backup battery, switching RAM around, etc.

Does all of the above indicate that the main board is fried, probably with regard to the ATA controlling function?

I guess I can still use for parts...transplanting a main board may be possible, but I would need to find that part for cheap...

 

[beachycove]

I had one that would start from a CD and not recognize the HD, or start from a HD and not recognize the CD. I did all the jumpers as per the manual, but it made no difference.

Have you tried starting up from the CD drive?

 

[Dennis Nedry]

Just for fun, you could try booting it from a CD, or from an external (and thus externally powered) SCSI HD.

The Pismo actually replaced the Lombard's SCSI with two FireWire ports. You could experiment with Target Disk Mode, attempting to format, install, or just access the Pismo's internal drive. You would need another FireWire Mac and the proper cable.

 

[J English Smith]

Thanks, all. I've got a firewire cable coming, needed one of those for some time. I doubt tho that I will be able to see the HD as I am pretty sure now that the main board ATA controller is what's fried. I found a used mainboard for just $23 shipped, so I am going to attempt a 'full Pismotomy' procedure next weekend and see if I can get the beastie completely apart without breaking anything. The case on this one is really nice so it would be nice to get this one working 100% again. This one came from a school system, it probably got zapped sometime with a bad power connection? Could not have been in service long as the case was in good shape - or it was in the hands of a teacher, not a student.

I've also got a plastic spluger coming and a long-handled #8 TORX. Any other special tools that are good to have on hand? I have all the usual screwdrivers etc.

 

[Dennis Nedry]

T8 and a small phillips will do most anything with a Pismo. There is one small nut, maybe 4-5 mm that must be removed to get the logic board out, but this can be done carefully with a small pliers if you don't have a socket that size. Other than that, just take your time and get ahold of an Apple service manual if you can. Nearly everything has to be removed to replace the logic board, it's a pretty extensive procedure but nothing too difficult.

Here are a few Pismo pointers:

• The plastic strip that has the power button in it snaps off, no screws.
  
• The processor board has a heat sink connected with a heat pipe. DO NOT disconnect the heat sink from the processor board or remove the two screws that attach them together. They carefully come out as one unit.
  
• When removing the processor board, disobey the service manual and pry very slightly on the corner of the board to assist when pulling on the plastic tab. The tab almost certainly will break otherwise, making it more difficult to remove in the future.
  
• The video cable is connected with a black T8 screw BESIDE it's gray ferrite thing. You will tear the cable if you do not remove this screw first. (I've done it long ago)

 

[J English Smith]

Thanks for the tips, Dennis, exactly the kind of 'inside info' I was looking for!

 

[J English Smith]

Successful logic board transplant yesterday...took me about two hours all told, and it would have taken less, but I put the lower case back together and then realized that I had left out the alum shield that sits over the ports in the rear. I am now in the process of upgrading that transplanted HD to 10.4.11 and all the necessary Java updates, getting Camino 10.6 back up and running, etc.

I was momentarily tempted to leave it running 9.2.2 for a while, but it wouldn't recognize the internal Airport card, just the pop-in Orinoco one that I use for my Lombard.

It was really quite a bit easier than I thought...now I will have to get that one with a cracked top case reworked, since I know how to pop the screens out now.

Thanks again for all of the help and advice...one more Pismo, back in service!

J

 

[Dennis Nedry]

Pismos are an absolute delight to work on. They were definitely designed to be taken apart and put back together.