exxos's Atari, Amiga & retro forum

stephen_usher wrote: 31 May 2023 12:17 I have the Mac IIsi PCB now and the amount of battery damage is huge. I pulled the battery out and a lot of the PCB surface came with it. Thankfully not near the chips I want to harvest.

These batteries are such a curse, but I expect that at the time they cared little for the chance these machines would be anything other than e-waste at this point in their lives.

Good luck with the harvesting.

... put a 3V Varta coin cell incl. holder in my Apple Macintosh IIsi. They don't run out that quickly, the disadvantage is that you have to change them more often...

Some cleaning up of the donor Mac IIsi board, first with white vinegar then water and finally Electrolube EML (which returned some of the solder on the pads back to shining silver and dissolved the battery crud with fizzing) shows the board is not too bad. The solder mask seems fine. There are one or two traces which can be seen to be dead which are directly under the battery but surprisingly few. However, the MDU and CPU have not faired so well. The MDU has lost a number of pins, as has the CPU.



Most importantly though, the RBV is untouched.

Maxell go boom...

:dizzy:

RBV transplanted, no change, well other than green video rather than grey. I need to check the soldering again. I do dislike surface mount stuff.

I'm now going to have to wait until the ROM SIMM arrives from the USA.

Double checked all the soldering and it's fine. After a few resets the display change colour to white during the reboot so that's "normal".

Looks like the RBV is fine but not being initialised fully.

With the help of the 68kmla forum I've discovered that early Macs have built in diagnostics in their ROM but you need to pull pin 2 of the first VIA down to ground to use it.

https://web.archive.org/web/20140921020 ... ostic+Mode

Useful for this machine... if the VIA is working that is.

stephen_usher wrote: 05 Jun 2023 11:56 With the help of the 68kmla forum I've discovered that early Macs have built in diagnostics in their ROM but you need to pull pin 2 of the first VIA down to ground to use it.

https://web.archive.org/web/20140921020 ... ostic+Mode

Useful for this machine... if the VIA is working that is.

Interesting, be nice if it works for you.

It looks like the ROM SIMM should be arriving on Wednesday, so that will help as I don't trust the original battery damaged ROMs.

Tonight I will be testing the connectivity of the VIA to make sure that there are no broken traces and if there are then add bodge wires.