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128k vs Rust

LaPorta

Well-known member
He was mentioning this because I currently have four 128k boards I am going to try and rehab that are in far better cosmetic shape than this. Yes, indeed, I can be persuaded to supply one for this if that is the route you’d want to pursue.
 

Durosity

Well-known member
I appreciate the offer. We’ll see where it goes. At present I’d describe my board repair skills as experienced beginner (despite many decades fiddling with stuff and working as an apple tech 20 years ago, but then that was just part swaps). My main concern at present is making it worse, but I’m pretty certain with some help we’ll be able to make some progress on it!

First thing I need though is to get it cleaned up so I’ll need to get a good ultrasonic cleaner first.. and I’ll need permission from SWMBO for that..
 

Phipli

Well-known member
I appreciate the offer. We’ll see where it goes. At present I’d describe my board repair skills as experienced beginner (despite many decades fiddling with stuff and working as an apple tech 20 years ago, but then that was just part swaps). My main concern at present is making it worse, but I’m pretty certain with some help we’ll be able to make some progress on it!

First thing I need though is to get it cleaned up so I’ll need to get a good ultrasonic cleaner first.. and I’ll need permission from SWMBO for that..
This is what I've been using in mine. Not sure if there is anything better out there as I haven't used anything else yet. Seems to work well enough. Cleans things and gets rid of flux.

 

LaPorta

Well-known member
I need to get one of those cleaners. Anyone recommend a certain size? Even for some larger, tower style boards?
 

Durosity

Well-known member
I was wondering how viable it was to do half a board at a time.. I was worried it may cause some damage to the components that were resting on the edge of the tray.

This is kinda why I was thinking of building my own, much like Bruce at Branchus has done. Something wide and long but not terribly deep.
 

Phipli

Well-known member
I was wondering how viable it was to do half a board at a time.. I was worried it may cause some damage to the components that were resting on the edge of the tray.

This is kinda why I was thinking of building my own, much like Bruce at Branchus has done. Something wide and long but not terribly deep.
I don't think it is an issue. The boards are touching the basket under the water anyway.
 

Durosity

Well-known member
So I’ve finally found some time to look at the 128k logic board after getting it cleaned up a bit. I’ve had to replace the caps as they were all leaking, but the pads for the positive connection have rotten through and won’t take any solder.. for the life of me though I can’t work out where it goes to to run a wire to.. anyone have any idea?
 

mgmac

Well-known member
my opinion, it's too compromised the motherboard, I had such a case many years ago with a Mac Quadra
I would get a new PCB from a re-128 Mac, keep the good chips and solder myself a new motherboard to use for the next 30, 40 years ;)
 

Durosity

Well-known member
Oh it probably is.. but I’m still gonna waste the time on it. I will eventually admit defeat.. one day!
 

Durosity

Well-known member
So I’ve borrowed a friends ultrasonic cleaner and I’ve managed to clean up the 128 board a fair bit! Now it does actually power up, but to black/white lines. It does the same with known working ROMs from another board, and indeed the same even if there’s no ROM on the board, so I suspect a r problem on the pathways before it gets that far… any thoughts on if that’s a fair assumption?

(And yes, I know the board is most likely toast, but if anything it’s a good learning experience 😅)
 

Durosity

Well-known member
So would I! I don’t think it’s likely.. but I wanna give it as much of a shot as I can. Alas at this juncture I’m not sure what the best next steps are.
 

cheesestraws

Well-known member
It looks to me like no code is running at all, or at least not enough to zero-init RAM: that's why the dead mac scrolls says it's ROM, but it could be almost anything in a board that's been in that condition. It might be oscilloscope time...
 
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