A1200 Keyboard mpu chip

[Fizzy]

Probably a daft question - but can the a1200 work without its keyboard mpu chip?  Dug up a rev 1A board and had a slight mishap where the chip has become seperated from the board.

I believe at some point it was going to be towered and a diy external keyboard adaptor hooked up to it.  Doesn't power up at all - just want to determine whether its duff or just needs a new mpu chip fitted.

Also - Which is the "best" revision 1200 board to get?  1A, or 1D.1?

[rkauer]

 The Amiga needs the MPU in place to run. Put it back!

 IMHO, the best board revision is 1D1.

[Fizzy]

Thanks for that - I'll have to see if I can get hold of a fine tip for my soldering iron, or get it repaired.

I've seen a 1D.1 board but it had problems with the display - when there was any disk activity, high cpu usage etc you would get interference on screen, regardless of whether through rgb scart, composite or rf connection.  This a common fault on those?

[rkauer]

 Bad caps!

 Swap them all.

 But a little advice: those two near the audio jacks are wrongly installed regular electrolytic ones. Use non-polarized units instead (22uF x 35V).

 IIRC, they are C323 and C333 on the mobo (any case, they are the two very near the audio jacks)

[adonay]

The best board IMHO is 1A ..  :-P  :-P  :-P  :-P

[taunusand]

What is the difference between 1A and 1D.1?  :-?  :-?

[adonay]

I belive the Escom 1D4 has all the mobo fixes done too so i havent found those more incompatible... Both 1A and 1D1 was made by CMB and were some of the first revisions with out price cuts in the components.. Later boards may have had different capicators etc such as the terible 2B although there are exeptions ...

As for the difference i am not sure i used to have a 1D1 it had issues with my Delfina so i swapped it for one of thoose new old stock mobos "1D4"