AtariGeezer #1 Posted March 14, 2016 Does anyone have a schematic for this board? I recently acquired two of these boards and neither of them function as a 16k board in Slot#1 or as a 32k board in Slot#2 on an 800. So I'm hoping someone has a schematic of these already that I an use to repair these... Thanks, Jay Quote Share this post Link to post Share on other sites
ClausB #2 Posted March 15, 2016 Sorry, no schematic, rather some troubleshooting tips. The 32K board is meant to work in slot 2 along with a 16K board in slot 1. Try that with the BASIC cart and see what FRE(0) gives. If it's less than about 37K then some part of the 32K board has failed. You could write a simple BASIC program to POKE and PEEK that RAM and see which bit doesn't work. Then remove the board and use an ohmmeter to trace that data bit to two RAM chips. Replace and repeat. 3 Quote Share this post Link to post Share on other sites
AtariGeezer #3 Posted March 16, 2016 Thanks for the tip, Claus These use the standard ram chips as on the Atari 16k boards. One board has the AM9016EPC chips and the other has MK4116N chips, so this will be easy to test those in an Atari 16k board one-by-one. The board with the MK4116N chips has Rust on many of the IC's pins and when I tried to lift one out of the socket, the pins broke off in the socket, so I'll have to see if I can replace those sockets. The board doesn't look like it can take much heat as the solder pads are very small compared to the Atari boards. I'll find out if it's just a bad ram chip or one of the others... Quote Share this post Link to post Share on other sites
Panther #4 Posted March 17, 2016 (edited) That's weird, I just happened to acquire one of these boards today (it was in an 800 I picked up). Edited March 17, 2016 by Panther Quote Share this post Link to post Share on other sites