Hello all,
In a Tektronix 4051 I have 2 out of 16 ROMs failing (MCM6832). One verifies bad in my programmer, the other verifies good but doesn't function in the 4051.
One dataline of this ROM pulses from 1,5V to 5V. Apparently the programmer says "1,5V is 0" and the 4051 says "1,5V is 1".
Anyway, I have replaced those ROMs with EPROMs and it seems to be functioning again. It crashes from time to time but that can be due to bad connections in my "quick and dirty" ROM adapter.
I have designed an adapter pcb to fit 2732 EPROMs. As soon as I have this fabricated I will know if the crashes remain.
Now I wonder what the expected lifetime of the ROMs is. These are 45 years old.
Here on the forum I read they last about 30 years max. On other websites I read they last as long as any other 74xx logic and EPROMs last only 10 years.
Now what is true?
Will it be wise to replace all ROMS while I'm at it? I have enough used 2732s in stock.
Or is it better to leave as much as possible original (the 4051 is placed in a museum) with the risk of having to open it up again within 6 months or so.
My quick and dirty adapter: