I used the desk for 2 year years on 40 meters. No issues. One day I turned it on and noticed both the plate current and Grid current meters pegged backwards. I pulled the RF deck and found the RF parts plate choke burned up on the mid section. I do not think this was the failure. I believe this happened over time. I remember one transmission where I was long winded and smelled something burning about 6 months ago. I found the original 4-250A tubes installed. This is serial number 265 so it came with 250s. I believe one shorted and that is why the meters where pegged backwards. I installed a new Eaglemade 10 to 160 plate choke. The choke is rated at 10KV and 3 amps. I had it on hand as a spare. Took 5 minutes to install. I also installed two known good Eimac 4-400 tubes. The desk is back up and running. I have it on the low taps at 2100 volts B+. I get 800 carrier and 3200 PEP, 120 percent pos peaks and 85 negative peaks as measured on my LP700 Station monitor.