Here we go.... (48G fixing and MEMORY UPGRADE)

[lemontea]

(05-25-2017 02:19 AM)mfleming Wrote:  Time to remove the CPU board and check the keyboard connections. The CPU board can be removed by turning the six (three each in two rows) twist tabs at the top end of the PCB. You probably already have Han's description of opening the 48 (congrats btw on what looks like a good job of it).

You can do a quick check to see if the ON key comes through on the keyboard connector. Not sure if I've seen a pinout diagram, but I think it is like the Pioneer keyboard connector. There should be two contacts dedicated to the ON key to wake up the CPU and should measure several hundreds of Ohms when key contacts are closed. Check to see if it's working. If not, oh my! I can't suggest anything else that might help.

Hopefully you're dealing with the usual keyboard contact to CPU board problem, the fix for which is documented in several places.

Good luck!
~Mark

OK thanks!

I am a bit tired opening the thing (it's nuts! haha!) so will try this later.

While I'm at this, can anyone confirm if this is the 128K RAM chip to use? (If I can't fix this 48G it will be for my other one).

http://www.mouser.com/Semiconductors/Mem...LL&FS=True

UPDATE: I think I found the correct one here

http://www.mouser.com/ProductDetail/Cypr...j1wA%3D%3D