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TAM - dark screen

thewap

thewap

macrumors 6502a
Original poster
Jun 19, 2012
555
1,360
After finishing working on my SE/30, am about to tackle my TAM with dark screen. I have owned this TAM for over 10 years, worked fine until I let it sit for a while unused.

Symptoms -

TAM power supply led turns green no problem.
TAM powers up and chimes.
Screen totally black.

Tried :
reset button (black purge button) -
changing pram battery
reseating ram
changing HD
trying to boot from CD (CD works- at least sounds like it and door opens)

Any opinions appreciated !
 
Try shining a torch at the screen at varying angles to see if you can see a faint normal picture. If you can, then you may have a bad backlight inverter or backlight bulb.
 
MacTech68 said:
Try shining a torch at the screen at varying angles to see if you can see a faint normal picture. If you can, then you may have a bad backlight inverter or backlight bulb.
Click to expand...

Zero picture with flashlight right against the screen, no faint image etc.
 
MacTech68 said:
Try removing all RAM and any cards. You should get error chime on power-up. Re-insert RAM only and try again.
Click to expand...

Ok, will get to it tomorrow (it's late where I am) and post result.
 
MacTech68 said:
Try removing all RAM and any cards. You should get error chime on power-up. Re-insert RAM only and try again.
Click to expand...


OK, removed all cards (ethernet & Sonnet accel.) , removed ram, purged, rebooted, boot chime and 5 error chimes, - no picture. turned it off, reinstalled the ram, rebooted, boot chime, - no luck - screen is still dark.
 
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sounds like backlight went out or inverter board. The TAM screen is a powerook 3400 screen so you could get parts easier than getting a new TAM screen.
 
havokalien said:
sounds like backlight went out or inverter board. The TAM screen is a powerook 3400 screen so you could get parts easier than getting a new TAM screen.
Click to expand...

Do you know where the inverter is located?. Trying to find TAM repair manual - no luck, just the user manual seems to be available.
 
OK, I've seen failed IDE hard drives on these early IDE Macs hold up the BUS, despite a startup chime. I can't recall if they will get to a disk icon with question mark without a hard drive connected. Worth a try if you haven't already.

I'd also be suspicious of RAM edge connectors having intermittent connectivity. Sometimes the slot itself needs some contact cleaner as well as cleaning the edge-fingers of the RAM module.

One other thing, as these machines age, is the motherboard edge connector connectivity. I used to see the 52/6200 63xx, 54xx,64xx 55xx,65xx with intermittent motherboard edge connectors. A real pain to check especially on the TAM, the take-apart to get to it is a bit of a cabling night-mare.
[doublepost=1473532004][/doublepost]
thewap said:
Do you know where the inverter is located?. Trying to find TAM repair manual - no luck, just the user manual seems to be available.
Click to expand...
See step nine here:

https://www.ifixit.com/Teardown/Twentieth+Anniversary+Mac+Teardown/12702

Looks like it's integral to the interconnect board.
 
Ok, will try the easy methods first, then tackle access to or removal of the motherboard - flat cable nightmare!.

PS - thanks for your suggestions !
 
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MacTech68 said:
Also found cosmichobo's youtube video take-apart (which he made after being frustrated that no take-apart exists).


ref: https://discussions.apple.com/message/7752782#message7752782 (youtube link therein is broken)
Click to expand...


yeah I watched that video, cringed when he was pulling the upper case plastic piece !:eek:
[doublepost=1473538403][/doublepost]
MacTech68 said:
OK, I've seen failed IDE hard drives on these early IDE Macs hold up the BUS, despite a startup chime. I can't recall if they will get to a disk icon with question mark without a hard drive connected. Worth a try if you haven't already.
Click to expand...

THIS!

Looks like my replacement IDE drive was also bad. TAM's screen woke up disconnecting the drive to ?. Inserted the original TAM CD and booted up to install. You just saved me a ton of dismantling hardship ..thank you!

Luckily I still have the Sonnet L2/L3 install CD for the accelerator, a little miffed to lose my files tho..but heck I guess I need to start fresh from the 90's...
 
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MacTech68 said:
Also found cosmichobo's youtube video take-apart (which he made after being frustrated that no take-apart exists).


ref: https://discussions.apple.com/message/7752782#message7752782 (youtube link therein is broken)
Click to expand...

Thanks for this link. A very interesting video Cosmichobo!
I'm not planning a full disassembly on my new arrival as it's functioning perfectly, but at some stage would like to replace the original 2GB hard drive.
 
MacTech68 said:
Phew - glad to have resolved that one. :)
Click to expand...

Could you refresh my memory on formatting an IDE drive for the TAM? - running into a little bit of a snafu.

Trying to initialize an Apple branded seagate 100G 2.5 IDE drive , not recognized in OS9 's disc set up in my blue imac in a IDE -usb enclosure, can't run disc set up 1.7.3 or 1.5 in OS 9, drive mounts up but not recognized as an Apple drive when trying to initialize. (not recognized through usb?)

Drive won't mount up in TAM (I get the dark screen again) - figure the drive is not set up with appropriate drivers to be seen ?.

Drive is seen in OSX, tried formatting the drive in PPC mode in OSX in two partitions then tried to see if it would be seen as formatable on the imac G3 to no avail.

Thinking some IDEs are not all blessed for all macs..
 
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IIRC, the 5xxx and 6xxx machines had an on-board IDE driver in ROM, early machines partition map didn't contain a driver partition at all, at least the LC630 didn't. The driver loads off the disk (if present) sometime after post.

When you used OSX, did you partition it as 'Apple Partition Map' rather than 'GUID' or 'Master Boot Record" ?

What I've noticed is that if you select the 'APM' and partition, but then use 'erase' on a Volume, OSX will write a 'GUID' partition map to the drive. :mad:

IIRC Drive Setup 1.7.3 is the minimum you should use, and it should work with any drive connected natively to the IDE BUS. It doesn't work with ANY drive over USB or Firewire on classic MacOS.

If you connect the drive's data cable, but leave the power cable disconnected, then boot from the CD, and run Drive Setup 1.7.3 from floppy, you may get away with connecting power to the drive, re-scanning for drives and see if you can format/initialize the drive. According to Apple, again IIRC, "low-Level" format on IDE drives is the same as "write zeros" option selected and isn't really 'low-level' at all. The Low-Level Fomat option was greyed out in later revisions of Drive Setup for ATA drives.

I know the above sounds potentially catastrophic, but I've used that method without damage to prevent whatever it is from balking the system.

Be prepared that when you connect power to the drive, the system may bomb/freeze/lock-up if it gets upset by dynamically attempting to load drivers or partition info from the drive.

The only other alternative that I can see would be to pop the drive into, say, a Windows PC, and delete all partitions and f-disk it so it's essentially blank. I haven't done that on systems since WinXP and I believe that from Vista onwards things changed with respect to formating drives. :eek:
 
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MacTech68 said:
IIRC, the 5xxx and 6xxx machines had an on-board IDE driver in ROM, early machines partition map didn't contain a driver partition at all, at least the LC630 didn't. The driver loads off the disk (if present) sometime after post.

When you used OSX, did you partition it as 'Apple Partition Map' rather than 'GUID' or 'Master Boot Record" ?

What I've noticed is that if you select the 'APM' and partition, but then use 'erase' on a Volume, OSX will write a 'GUID' partition map to the drive. :mad:

IIRC Drive Setup 1.7.3 is the minimum you should use, and it should work with any drive connected natively to the IDE BUS. It doesn't work with ANY drive over USB or Firewire on classic MacOS.

If you connect the drive's data cable, but leave the power cable disconnected, then boot from the CD, and run Drive Setup 1.7.3 from floppy, you may get away with connecting power to the drive, re-scanning for drives and see if you can format/initialize the drive. According to Apple, again IIRC, "low-Level" format on IDE drives is the same as "write zeros" option selected and isn't really 'low-level' at all. The Low-Level Fomat option was greyed out in later revisions of Drive Setup for ATA drives.

I know the above sounds potentially catastrophic, but I've used that method without damage to prevent whatever it is from balking the system.

Be prepared that when you connect power to the drive, the system may bomb/freeze/lock-up if it gets upset by dynamically attempting to load drivers or partition info from the drive.

The only other alternative that I can see would be to pop the drive into, say, a Windows PC, and delete all partitions and f-disk it so it's essentially blank. I haven't done that on systems since WinXP and I believe that from Vista onwards things changed with respect to formating drives. :eek:
Click to expand...

Yes I formatted the drive using APM and clicked option for PPC, then partitioned it into 2 partions 40/60. The data cable on the TAM also gives power - no separate power cable to the 4 outside pins - (there is the fan cable hook up off the HD mounting frame). Thinking maybe my data cable could be bad?.


Just tried another drive from my drive graveyard.. this one is being seen..think I'm getting somewhere.

Failed..same problem. Think I'm going to source other drive besides my graveyard ones..
 
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Does the HDD need to be set master/slave on the four outside pins? This varies so much between machines and brands that it might be worth a try.
 
Well been trying to have a newly rebuilt Apple branded IBM 2G drive (exact same as original) recognized to no avail yet. Outside 4 pins are open, so I believe set to "master"- but original drivers obviously not on it.

When I have time will try using my pismo as a slave enclosure for the new drive (open up the pismo and replace the drive with unformatted one) and try to set up disk via CD with OS 9 CD. Tried the TAM CD , and disk set up 1.3.1 but pismo will not recognize the CDs. I don't think the pismo will recognize any pre- OS 9 CDs.

If I can source the drive enclosure (MCE) for the pismo, I guess since that is a pata IDE bus, I suppose I will have the same problem having disk set up not support a second drive to initialize or set up? - (using the CD module / IDE Pata in Pismo, the CD is recognized in disk set up).

however not sure if MCE is still open as there is no reply to my order of their enclosure for over a week.
 
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Pismos came with 9.0.4, although some also with 9.0.2. I have both sets of original install/restore CDs. I would use 9.1 and above if generic installers to be on the safe side as anything earlier is unlikely to contain the drivers to get the Pismo up and running. As for the MCE, for this one operation it is only a few minutes work to remove the hard drive from the Pismo and pop another in to set up from scratch. I would not run to the expense of an expansion bay caddy.
 
weckart said:
Pismos came with 9.0.4, although some also with 9.0.2. I have both sets of original install/restore CDs. I would use 9.1 and above if generic installers to be on the safe side as anything earlier is unlikely to contain the drivers to get the Pismo up and running. As for the MCE, for this one operation it is only a few minutes work to remove the hard drive from the Pismo and pop another in to set up from scratch. I would not run to the expense of an expansion bay caddy.
Click to expand...

I have 9.2.2 and 10.4.11 on the pismo. I will try to set up the new drive for the TAM by inserting it in the pismo, and see if I can format the new drive with disk set up. The external bay enclosure I want anyway so that I can use it for backups on the Pismo.

Not sure which 9.0 OS I have on CD..

PS: which reminds me I need to get the original pismo CDs..
 
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