TAM boot issues, appears to be HDD, any advice?

[jsarchibald]

I just got another TAM, and it has the same issues as big450. A chime when turned on, but nothing on the screen. I swapped the RAM and VRAM chips with my other TAM, no good. Tried swapping the batteries, no good. Then I put everything back as it was, and it booted, but only to a picture of a disk with a question mark.

However, I now get error code 97, finder 10 error, bus error, etc, randomly when I boot with the System CD. When it does boot up, I get the HDD show, but everytime I try to copy the system software to the HDD, or initialise it, etc, it will freeze up. I've come to the conclusion it is the HDD, which is a 17mm ATA 2GB drive. Anyone know where I can get one of these, or if the issue might be something else? Cheers.

 

[jongleur]

I thought the TAM could handle upto a 128GB drive, but the mounting points on the newer drives may be different distance part? Do you have another 2.5" drive you could test with?

 

[jsarchibald]

Turns out it isn't the HDD! I swapped the drive into my working TAM, formatted and loaded System 7.6.1 from the TAM CD, and it worked great. Swapped it back into this TAM, and now no screen again. Not sure what the problem is?

 

[jsarchibald]

Ok, I now have it booting to the Mac OS screen, and it freezes there every time. I can press the spacebar and it says Extensions Disabled, but it still freezes. It still comes up with a 'bus error'.

I know the RAM, VRAM and HDD are good, as are the keyboard, battery and PS. I've done the resets, etc. Any ideas?

 

[beachycove]

Master/slave settings?

 

[jsarchibald]

How are these configurable on the TAM? I don't know a lot technically about the TAM, sorry.

 

[LCGuy]

Like any other machine, you set the jumpers on the HDD. The TAM is the same as a Performa - it has an IDE HDD, but a SCSI CD-ROM. The HDD will need to be set to Master, as for the CD-ROM - if the system has never been opened before you shouldn't have to worry about it, but regardless it should be set to ID 3 with Term power.

 

[Byrd]

If the HD worked in your other TAM - it should work fine here. Try the HD cable too. Have you tried booting off an external SCSI device?

 

[beachycove]

I don't think I've ever so much as seen an actual TAM, so I did not know the CD was scsi.

There could be a problem on the scsi bus, though, now that scsi has been mentioned. Cables can go bad; so can termination circuitry — but where would you get a TAM CD-ROM if you needed to replace one these days?

My most recent experience with a bus error message involved a dual 604e in a PCI Mac. The card (200MHz) was possibly too fast for the logic board, as a slower dual 604e (180MHz) works perfectly in the machine. I still need to test the 200MHz card in another machine. But in this instance, I had random freezes and also bus error messages that ceased with the replacement of the processor card.

What this suggests to me is that error messages generated by the system in some cases may not be especially helpful, and that it may be necessary to diagnose more systematically by swapping parts between the units one at a time. Painful, I know, but possibly necessary if all else fails.

 

[jsarchibald]

I thought the drive was an ATA in the TAM? I tried the good HDD in this one, with the same issue, and it doesn't look like anyone has played around internally at all. Any other ideas?

 

[LCGuy]

Nah, they're exactly the same as a Performa - ATA HDD, but SCSI CD-ROM. The CD-ROM in the TAM is supposed to be a heavily modified AppleCD 600i IIRC, which means that theoretically you could potentially gut a standard AppleCD 600i in order to repair it.

 

[jsarchibald]

Hi, just wondering if anyone else has any ideas on this one?

I've tried swapping the parts between a known working unit, and this one. I've swapped RAM, HDD, Cache card, basically everything that is accessible on the rear of the TAM without disassembly. I've tried booting with the internal CD drive, and an external one, but I still get it freezing on the 'Welcome to Mac OS' screen.

All of the components also work on my good TAM, so it has to be something else. It seems to run perfectly apart from this issue, so I'm guessing it is a very minor issue. I feel like I am 99% of the way there with it, it has a great hard drive, CD drive, the monitor is great, just the freezing.

Thanks for any help you can give!

 

[johnklos]

Have you removed the heat sink and reapplied heat sink compound?

 

[applefreak]

- PRAM reset

reset PRAM (hold down Command, Option, P and R keys when starting the computer until hearing 3 x startup sound

reset PRAM doesn't clear all the PRAM

- CUDA reset

Press the Cuda Switch. It does have a positive détente, you'll feel ever so slight a click when depressing it.

CAUTION: Use only non-conductive items to depress the button.

You are advised to hold it depressed for at least 30 seconds.

- Installing the Crescendo/L2 takes a few easy steps:

1 Install Mac OS 9 (if upgrading as part of this installation)

2 Install Sonnet software

3 Shut down computer

4 Remove case cover from computer

5 If installed, remove Level 2 cache card

6 Reset CUDA switch on logic board

7 Install Crescendo/L2 card into L2 Cache Slot

8 Replace case cover onto computer

9 Affix the Powered by Sonnetlabel to front of computer

10 Turn on your newly upgraded computer

11 Reset computer’s date and time

 

[jsarchibald]

Just wanted to ask some advice - if my TAM is coming up with an Address or Bus Error, is this related to communications between the RAM and the processor? And if so, what would happen if I install my Sonnet G3 card and the HDD with the Sonnet software on it, into the faulty TAM?

The problem is always after loading extensions but before loading the OS desktop, so I'm thinking if the Sonnet card is recognised before the stock processor is, I might bypass the problem area. Any ideas are welcome, this theory was cooked up in my own mind, and I'm the type to experiment with something to see if it works. Just haven't had the time recently to put this theory to the test.

 

[Byrd]

At startup with the G3 card, the onboard 603e CPU is doing all the work until the Sonnet extension loads. You'll note that the Sonnet extension will load first up, resulting in a much faster boot. If it isn't, you can rename the file with a 1 or something at the front so it is loaded first. I'm fairly sure the 603e CPU isn't "disabled" as such but still running, with no CPU load.

Does the Sonnet G3 make the faulty TAM work any better installed?

JB

 

[techknight]

for shits and giggles, try heating the board up. See then if it clears up.

 

[eweri]

Well - if you replaced every replaceable part with a known good one. Then the fault has to be in the non replaceable parts - the main board.

My guess: the processor or cache is damaged.

AFAIK every system starts up with caches disabled and at some point in the boot process the operating system activates the caches. So if the system boots and crashes right after that, i guess it is the cpu/cache

If you are in luck it is a bad solder point and it could be repaired easily. Try to put some pressure at the cpu or other chips at the main board and try to boot. You can also try ice-spray (CO2 spray) on different points at the main board. Every test with one point at a time.

If possible put the TAM in the fridge and when it got cold take it out of the fridge and boot it ASAP. (Attention - air humidity can kill the TAM!) I got some hard drives up with this technic for the final backup . If the TAM boots when it is cold this could be a sign a bad solder point.

Just my ideas, bye

eweri

 

[Byrd]

If possible put the TAM in the fridge and when it got cold take it out of the fridge and boot it ASAP. (Attention - air humidity can kill the TAM!) I got some hard drives up with this technic for the final backup . If the TAM boots when it is cold this could be a sign a bad solder point.

Please no - that's terrible advice, unless you want a $1000+ paperweight! It will short out and all the special magic smoke will come out. Maybe just use the freeze spray?

Have to say I went through two tins of that freeze spray trying to diagnose a faulty LCD digitizer board in my TAM. Didn't help, it was moreso the very fragile ribbon cable/connector which was irrepairable. When you open a TAM, you'll discover lots of messy cabling inside.

JB