Didn’t know there was a forum here, glad to find this and join you all. Hopefully someone will have a moment to take a look at what I’m experiencing here, and let me know if in fact my SAD1024A is bad. Thanks!

I recently acquired a V1/V2 DEM, I say that because the model number stamped on the board is EH1318A, not 5150B:

The problem with this unit is the flange effect is really weak, all other functions sound decent, including the Color and Range knob, even the Rate knob has a subtle effect.

I looked at the signals going in to the Balance trim with a scope, and one of my signals is missing, you can see the purple wave behaves correctly, but the yellow wave is not moving at all:

I am observing the best practices I know how for ESD when working on this, wrist strap and anti-static mat both connected to ground:

I put in new e-caps, and a socket for LM324N, and replaced LM324N with an era correct one, have not yet replaced the tantalum caps:

All of these voltage readings are with the SAD1024A chip removed from the socket.

LM324N – this chip has been replaced with a socket and NOS LM324N:

RA4588NB:

LM311N:

LMP741N:

MC14013B:

SAD1024A removed from socket, these voltages are from the socket:

Hopefully someone will be able to spot a problem, and let me know if it’s the SAD1024A. Thanks again!