THAT4301 Retrofit module - Vee shorted to GND?

[chemicalwill]

Hello all -

I am troubleshooting my Schalltechnik_04 Pumpernickel comp. However, I'm not getting any sound out of it.

In doing some continuity testing, I discovered that Pin 10 is shorted to GND. I removed the chip from the socket and on the board, I don't get any beeps between -9V and GND, but on the module itself, I do.

Is this consistent with an internal short on the module?

Thanks!

 

[Cybercow]

Pin 10 on the THAT4301 is the Vee (negative voltage) supply pin. It appears that the THAT4301 calls for a dual-rail ± supply and if the circuit to which you are referring is indeed using a dual-rail supply, then pin 10 to ground is a problem.

In some circuits, Vee is commonly shorted to ground when single-rail supplies are used.

But without a schematic, there's no way to know what is supposed to one happening.

 

[chemicalwill]

Pin 10 on the THAT4301 is the Vee (negative voltage) supply pin. It appears that the THAT4301 calls for a dual-rail ± supply and if the circuit to which you are referring is indeed using a dual-rail supply, then pin 10 to ground is a problem.

In some circuits, Vee is commonly shorted to ground when single-rail supplies are used.

But without a schematic, there's no way to know what is supposed to one happening.

Thank you for your reply. I have reached out to the builder but I certainly don't expect him to release his schematic.

However - I did find this schematic/tracing from someone else. I don't see any compelling indication that -9V and GND should be shorted, there are several different points on the PCB that are specific to -9V and GND.

My real question I suppose is... Vee and GND should NOT be shorted on the retrofit module, correct?

 

[Robert]

Correct, VEE and GND do not have a direct connection on the retrofit module.

I'll measure the resistance on a module today and see what it reads.

 

[Paradox916]

Might find this helpful,

https://s44936ecb73249310.jimcontent.com/download/version/1584036360/module/10277934168/name/4301-4305%20transition-guide.pdf