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500-series logic board swap?
Posted by: AndyO on 2023-01-04 13:18:59
This might be a simple question, but can I replace the logic board in a PB 540c with one out of a 520c?

My 540c died (again) a few weeks ago, and it looks to me like the main board is rather corroded. But I have an almost-working 520c which has totally broken hinges that was intended to be a donor system, and looks to have a good logic board, if they can be swapped over without complications.
Posted by: beachycove on 2023-01-04 16:03:25
Since the processor is located on a daughter card, I would assume yes.
Posted by: Byrd on 2023-01-04 16:04:56
Yep 100% straight swap, boards are the same (usually same part no.), just different CPUs
Posted by: 3lectr1cPPC on 2023-01-04 16:05:01
Agreed, they should be the same.
Posted by: Paralel on 2023-01-04 16:54:57
I have done exactly that before. It's no problem. There are different logic board revisions, but they are all interchangeable.
Posted by: AndyO on 2023-01-04 17:00:09
Excellent! Thanks all - now the weekend project!
Posted by: AndyO on 2023-01-07 08:00:10
Well, that did not go well at all. The 540c has apparently been worked on before, and not carefully judging by the bent pins and connectors, and incorrectly fitted (jammed) parts.

But, firstly, taking one of these things apart is way beyond my current level of dexterity and motor skills, and secondly, the 540c is in really dire condition internally. Looks like it was submerged for some time, and is very badly corroded and rotted in places. With the vinegar syndrome screen, there's nothing much to salvage - except possibly the hinges to donate to was was going to be the donor 520c!
Posted by: 3lectr1cPPC on 2023-01-07 17:13:11
Attach some photos, I'm curious how bad it is. That really stinks though, although the screen is salvageable, you can install new polarizer film, although it is quite difficult.
Posted by: AndyO on 2023-01-08 07:15:33
Attach some photos, I'm curious how bad it is. That really stinks though, although the screen is salvageable, you can install new polarizer film, although it is quite difficult.
Too late, I ditched the corroded parts and scavenged what I thought was worth keeping, such as the drives, interconnect ribbons, case screws, keyboard and the entire display assembly, complete with plastics and hinges. I also kept the trackpad and RAM card. The logic board had been worked on previously it seems, and not competently, and the plastics were in poor shape. Its internal frame was badly corroded and pitted, and the whole thing had a very unpleasant smell once I was disassembling it.

What I will plan for instead perhaps is to switch some parts into the what was planned to be the donor 520c, which has broken hinges and no floppy, but that's going to have to wait since it taught me that I don't have the manual dexterity for this sort of work any longer, so that will be the last strip down I do - for a while at least. I can just about manage the bigger stuff like the Classic and 630 which are not so fiddly, but not so much the fine/tight work in more compact systems.
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