VMP-4000e Pad Not Working

Posted: Wed Nov 19, 2008 3:17 am

Hey Gang,

Channel 2 on our VMP-4000e has a pad switch that doesn't pad. It passes audio but neither the -15 or -25 position actually attenuate the audio.

What would cause this? How do we fix it? Does anyone have a schematic?

Thanks!

Posted: Wed Nov 19, 2008 5:24 pm

The mic pad happens to be 2 inline resistors with pins 2 & 3. Then there is the ALL IMPORTANT LOAD RESISTOR that pretty much does the actual paddin'....see? So if it is still passing mic audio with and without the pad switch engaged? Then it can only be the load resistor between those 2 resistors which are not making contact due to a failed switch or cold solder joint and/or, dirt. But it IS THAT RESISTOR and nothing else.

That'll be $80.00 Thank You
MS Remy Ann David

Posted: Wed Nov 19, 2008 7:03 pm

No pad operation points to the switch being open circuit.
Most likely fault is the connection between the motherboard and the front panel channel board..

Take the lid off with the unit facing you..

Locate the 10way cable between the front panel channel #1 area
and the main mother board where the valves are attatched to.
This should be the leftmost cable.

Unplug this cable taking note of which direction the colours are
and examine the pins on the front panel board for channel #1.
Also look at the #1 pad switch from the front panel board angle
and look for any broken tracks etc.

Re-plug the cable onto the connectors that it originally came from.
Press firmly down ( not too hard !) so that the connector is properly in place.

Power up and test...

This topic sponsored by: