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Memory Problem Dual Deltafex

Posted: Fri Jul 08, 2022 7:43 am
by Adrian Lancer
My silver face Dual Deltafex won't hold memory anymore. Is there a battery inside the unit or am I consigned to a manual input every time?

Re: Memory Problem Dual Deltafex

Posted: Wed Jul 20, 2022 2:26 am
by JamesPaul
I am relatively confident that all those old fex amps had a battery in them.

Open it up, drain any power supply filtering capacitors, and take a look around. I think most were the computer button cells, 2016, 2032, etc.

Re: Memory Problem Dual Deltafex

Posted: Sun Oct 09, 2022 9:01 am
by noelmem1
my unit now has sort of steady tinny crackle that goes louder with the reverb effect .
I dont see any battery for the memory - they could have used a Flash Memory chip .
Somebody went in to fix this before it went to ebay as the glue supposed to be on top of the screw was under it.
I will try the scope and try locate he source. I it is not a bad opamp then there could be no fixing this due maybe to custom ROM code in the SOC .

noelmem1

Re: Memory Problem Dual Deltafex

Posted: Sun Oct 09, 2022 8:25 pm
by noelmem1
cleaned the board with Contact cleaner and brush , drying it today under the sun , then let me try it out tonite , if still , then there are 6 opamps to try replace . The TDS220 Tek scope is out of commission due to old display - darn LCDs they die after 20 years .

noelmem1

Re: Memory Problem Dual Deltafex

Posted: Sun Oct 09, 2022 8:28 pm
by noelmem1
oh yes ,i have pulled cleaned , lubed with oil based contact cleaner the 28 pin Chip in the socket - the primary unreliable socket connection- they should have used the gold plated round hole sockets .

noelmem1