Why you should change your capacitors... Re: PB 100


MacTech68

macrumors 68020
Mar 16, 2008
2,188
152
Australia, Perth
Interesting, however, removing the capacitors using the pliers method could potentially rip tracks from the board.

Good job getting it going to that point. Have you managed to get the HD going?
 

robivy64

macrumors member
Original poster
May 29, 2004
46
0
Fort Worth, TX
Well, the trick is to rock it back and forth and then pull. I've recapped dozens of electronics using this method and have never pulled a trace.

The HDD is toast. I have a couple of Toshiba SCSI drives coming in the mail that should do the trick.
 

MacTech68

macrumors 68020
Mar 16, 2008
2,188
152
Australia, Perth
Well, the trick is to rock it back and forth and then pull. I've recapped dozens of electronics using this method and have never pulled a trace.

The HDD is toast. I have a couple of Toshiba SCSI drives coming in the mail that should do the trick.
Fair enough. I've always de-soldered them using some fresh solder to reflow.

What make/model is the toasted drive? I remember the IBM models worked if light pressure was applied to one of the large ICs - no doubt a cracked solder joint on one of the pins. I saw heaps of them with that fault, but only ever needed to put them into a jig to get customer's data before replacing them.
 

tdiaz

macrumors 6502
Feb 7, 2006
449
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But do you have the Funky RF Controllers? :)

I've got two Apple IIgs motherboards that I need to do some capacitor swapping on. I've not really gotten into capacitor theory much. Is there any reason why the electrolytic can't be swapped with tantalum instead of aluminum?
 

MacTech68

macrumors 68020
Mar 16, 2008
2,188
152
Australia, Perth
But do you have the Funky RF Controllers? :)

I've got two Apple IIgs motherboards that I need to do some capacitor swapping on. I've not really gotten into capacitor theory much. Is there any reason why the electrolytic can't be swapped with tantalum instead of aluminum?
I've usually used Tantalums as a replacement for the small values. They don't leak and the worst they'll do is short, which generally shuts down the power supply without doing any damage (and they're easy to spot when they short).

Case size choice is the key, since some values come in different case sizes and one size may not fit the thin and narrow constraints of the SMD Electrolytic solder pads.

IIRC the Quadra 700, 800 and IIfx are the only Macs on which Apple used purely Tantalums. Why don't more machines use them? Cost. An SMD Tantalum is typically 3 times the wholesale price of an SMD Electrolytic.
 

MacTech68

macrumors 68020
Mar 16, 2008
2,188
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Australia, Perth
And finished!

Just finished upgrading to system 7.5.3!

Part 2
Nice. I wonder if the old "Disable Unit Attention" is the problem with needing to reset the PB to get it to boot? How you'd set that on that CF adapter, I have no idea. It was a jumper on most SCSI drives.

Shame about the other LCD. Are there other caps hidden under the plastic housing of the panel itself?

Well done. I love the SCSI - CF adapter! :eek:

The last drives Apple was supplying here was a 200MB IDE Seagate with a low profile adapter PCB that bolted to the bottom and converted it to SCSI. Only to suit 12.5mm height IIRC. Fascinating bit of kit.

EDIT: Probably this Stratos adapter, supplied by the same folks at artmix:

http://translate.googleusercontent.com/translate_c?depth=1&hl=en&rurl=translate.google.com&sl=ja&tl=en&u=http://www.artmix.com/powermonRX.html
 
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robivy64

macrumors member
Original poster
May 29, 2004
46
0
Fort Worth, TX
This is the oldest (and slowest) Mac I have ever owned.

Man, it takes FOREVER to unstuff files. I do, however, love the convenience of using a CF reader to copy large files directly to the "hard drive".