I have a 16K memoryboard for my HP9825A it suffered from a bad -12V and
destroyed all the rams TMS4080.
I bought from ICI 32 pcs. nos uPD411AC-2 replaced all the rams but I'm
getting an error when testing the board.
The HP9825 isn't under suspect because it works okay with another 16k board.
The systemtest (from the tape) says : 60K board failes
Address 60100,60300,60400 not always the same sometimes only 60400.
Bit 9 sense 0 or 1 (not consistent sometimes 1 sometimes 0) I swapped the
LB9 and UB9 chips on the board with other 411's(new ones)
But the error stays I replaced the refreshcounters decoupling caps but
nothing.
So any ideas are welcome.
-Rik