Michael Grossman wrote:
>Cavernosum, I bought a broken polysix which plays in tune and sounds
>great except the programmer is flakey. Upon probing IC22-13 (DB1) I
>noticed the pin has very low amplitude (<2V). I thought perhaps the
RAM >chip might be bad so I pulled IC22-13 out of the socket and
confirmed >the amplitude is still low. I am now convinced the
uPD8048-245 is bad.
Not necessarily. Have you checked IC31? On units with battery
leakage, this is one of the most commonly damaged ICs. Try replacing
that; if it still doesn't work, I'll sell you a new CPU.
>I would also like to buy a replacement 1kx4 static ram (TC5514APL-3)
if >available.
Good news: you can use a 6514 RAM chip and it works exactly the same.
These can be ordered from Jameco Electronics for about $4 each;
Jameco part number 43238.
~GMM