Sunday, January 6, 2013

IIGS Upgrade Change of Plans

I have been struggling to get libftdispi to output anything of use and dealing with libmpsse constantly freezing the UM232H, so I decided to try a change of challenges for the day:

I have been checking ebay for a good deal on a IIGS logic board. I finally found one for a good price and it's local so I can avoid shipping costs. However, after taking a close look at the pictures of the board, I realized that the standard IIGS logic board does not have the connectors for the Apple IIe power supply and keyboard (it does have the solder points though). Fortunately, the connectors are pretty standard. I figured though, if I am going to have to pay over $40 to solder connectors on a new logic board, I may as well try to repair my own board. So the logic board went into the dishwasher to get cleaned up. I have had good results cleaning a board this way, just make sure to dry it off completely! The board is a mess. There are vias that are corroded completely through, leaving a cumbly substance behind. There are traces that are completely gone. Some traces are corroded under the solder-mask, so you can't even tell there is a problem at first. There are surface mount resistors that have a pad corroded through. A couple of hours of mask scraping, continuity testing and soldering tiny wires got me here:

Repairs to Battery AreaRepairs to Back of Board

Resistors R193 and R14 had to be removed

Now I have to find the appropriate resistors to replace the corroded ones. I can't find any surface mount components locally, so off to ebay...

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