Enforcer issues

[sunn-tanned]

No sound and front two tubes are red plating?
 Bias issue? Cathode resistor?

[loudthud]

What position is the 60W/100W switch?

[sunn-tanned]

100Watt

[Watson]

Bias pot (R72) on the V6/V8 pair maybe whacked?

[sunn-tanned]

The V6 stays red plating when on 60W
What would be the best process to check?

[Watson]

To check a resistor (or pot) one side must be removed from the circuit in order to get an accurate reading. 

However that said, if the behavior is the same with the selection in the 60W position, I would suspect there is a problem with the voltages powering the output tubes. 

There are many members vastly more qualified than me who perhaps can chime in.  But I would start by validating the power supply caps and voltages are correct.  Then that the tube sockets are all making proper contact.

You didn't mention is this amp new to you or has it been working fine and now its behavior has changed?

[sunn-tanned]

I acquired it this way, I did replace a broken polarity switch

[Watson]

I've experienced similar red-plating that cost me two of my output tubes in a Marshall JCM that had been stored for 13+ years.  In the end after a lot of debugging, giving the preamp and power amp tube sockets and tube pins a thorough cleaning eliminated all of the issues the amp exhibited with no components needing to be replaced other than the 2 tubes it fried and a couple of fuses that blew along the way.

If you don't have something already, I would highly recommend you get a CAIG SK-GXMD DeoxIT Gold Vacuum Tube Survival Kit. Amazon has them for less than Caig.  You can clean and protect both the pins and the pin sockets with this kit.

http://www.amazon.com/gp/product/B007K8M9JA/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

[loudthud]

You should take the amp to a local technician that can safely find and correct the problem. Red plating tubes can damage the transformers that you will never be able to find exact replacements for. I only have a schematic for this amp and there is no B+ fuse shown.

[sunn-tanned]

Thank you for the concern and I understand and last thing I would want is a blown tranny, owning about 50 different vintage tube amps I would be bankrupt if I had a service tech come to the rescue each time I had a problem without first taking the time to ferret things out. I just had a Mesa Triple Recto with volume fade that took a while to figure out but found a cold joint on the heater circuit.

I'm hoping maybe someone could share some areas I should start testing?

[Isaac]

I had a red plating problem with my 200S recently. I started by pulling all of the fuses and then recording the voltages on all of the power tube pins. That should tell you where to look next.