DBX 160VU compression pot has no effect

[Golgoth]

I have a DBX 160VU that stopped working properly after being transfered to a new rack.
They are a pair racked together and the other one still works just fine.

The compression ratio is stuck to infinity and the compression pot has absolutely no effect.
Thresh and make up work fine.

Where should I start to look first?
Thanks!

 

[pucho812]

Start with the psu make sure it is in working order

 

[Golgoth]

Start with the psu make sure it is in working order

The PSU of the affected unit is doing as well as the working unit's.
I took a bunch of measurements around the circuit and they were fine against the working unit.

The affected unit is sounding fine other than the compression pot not responding and the compression ratio seemingly stuck to infinity..
I measured the compression pot and it has the range it should have, I don't think the issue is related.

Wondering if a joint broke somewhere when moving the unit to the new rack? Not sure as the symptoms would be different/intermittent?
I did a visual check and all joints are shiny, I did not desolder the VCA and RMS cans to check inside them, I know there can be sketchy joints inside them..

The pair survived the journey between Nashville and Paris but failed to travel from a rack to the other at the studio

 

[pucho812]

Last 160 vu I addressed had solder joint problems at the vca.

 

[Golgoth]

Last 160 vu I addressed had solder joint problems at the vca.

What were the symptoms?

 

[Rob Flinn]

Last 160 vu I addressed had solder joint problems at the vca.

I think the last one I did had a dead 5534 in the VCA.

 

[Golgoth]

I think the last one I did had a dead 5534 in the VCA.

How was the compressor behaving?

Did you solder the can back to the PCB or installed pins to plug it on? Is the metal casing even necessary for proper function?

 

[Rob Flinn]

How was the compressor behaving?

Did you solder the can back to the PCB or installed pins to plug it on? Is the metal casing even necessary for proper function?

I don't remember what the compressor was doing, this was a few years back.

I took the pcb out of the can, installed a new 5534, then put it back in the can.

 

[Golgoth]

I don't remember what the compressor was doing, this was a few years back.

I took the pcb out of the can, installed a new 5534, then put it back in the can.

Okay I will try swapping the cans between both units to find the culprit, and maybe install some sockets onto the pcbs for the cans pins.