Another 1200XL mainboard, new problem (picky about booting cartridge, example BASIC, Defender)

[ACML]

For years I've always raved how reliable the the 1200XL has been for me, but lately, some are testing my nerves.  A board that otherwise has been 100% reliable, now is finicky about booting certain ROM carts and by "certain", I mean specific physical carts not titles.  There is one particular BASIC Rev A cart that now won't reliably boot on this board.  Same cart works great on all other Atari Computers I have.  Also, my Defender cart is acting the same way only on this board.  I can run the XEX version of Defender and the UNOcart equivalent of both BASIC Rev A and Defender no problem.  See photos below for random behavior.

 

BASIC boots normal and keyboard works.

 

Comes up with corrupted text and is locked up (no keyboard function).

    

 

Comes up fine.

 

Then not so much (locked up).

 

The only mods I've done to it are the ClearPic2002, R63 and 28 pin EPROM OS replacement.

 

I also ran a different BASIC cartridge in it and it worked perfectly every time.  Has anyone else found cartridge pickiness with a certain physical cart?

 

[ACML]

Being it's Sunday, I had to read up on AA if someone else had something similar happen.  There is a thread with regards to a 130XE with similar behavior.  Recommendations were to swap 74LS08, 74LS138 and MMU individually to see if one of those does the trick.  Tried all three separately, then tried the 74LS14 for good measure.  No change on any one of those.  Then I thought, while I'm here, "what controls boot"?  SALLY (6502C)!  I swapped out the SALLY and viola, working 100% again.  Something must be right on the edge with that particular SALLY and those mainboard components.  I love it when it all works out!

 

So, in hindsight, I'm noticing that to me , the SALLY (6502C) seems to be the one VLSI chip that has the most issues and failures.  Had to replace a few in the last year or two.  I think this one was a -12.  Where is this made?