3 Year old 7000DLE power out dropping to zero

[rbduck]

I started having an issue that I immediately thought I knew the answer to. I've searched the forum here and found only one vaguely similar issue. As stated in the title I am loosing power output when placing the transceiver in TUN mode. I am using the digital watt meter in my tuner with Peak hold, I mention that because of importance. This problem has a twist. the problem is this .

When I press TUN to allow a signal to cause the Palstar HF-Auto to tune, there is instantaneous power that drops back to about 5 watts.
The initial power seen on the HF-Auto peak hold is the power output set via the TUN slider. If set to 100, the power hits 100, then drops back to 0. The first thing I suspected was that the SWR protection set via the controls at Settings>General>An/Filters. Enable Protection and Disable on Tune Power <35W are not selected. I thought Thesis may have been seeing High SWR but that is 1.2:1 on the selected frequency or to a dummy load. I have also tried transmitting a CW or AM carrier with the same results. I tried the dual tone test for Pure Signal. The result is the same plus Pure Signal never locks.

Here is a twist. If I set to LSB and press PTT via a switch and speak into the microphone I see normal output from the radio. The only hit I get on a forum search is the possibility the bias may have drifted or off on high temperature. This occurs on a dead cold radio.

I've reset the database. I've uninstalled Thesis completely and reinstalled with a fresh database. If it were not for the seemingly normal output during a sideband transmission I would suspect a bad power output transistor (or two). I have not tried reloading firmware to the transceiver. I have not tested for proper bias. I am using Thetis version 2.10.0' I am using the Thetis power output meter, digital meter in the Palstar and Bird 43 to check readings.

Has anyone ever had anything like this occur? Is there another setting I need to be looking at I have not mentioned?

[rbduck]

For future reference I have resolved the issue. It seems the current adjustment on my Astron power supply had been bumped. It was to a point where it was not quite enough for the transceiver to obtain full power. It was the last place I would have thought to look. Doug made a suggestion. Through that suggestion, it led to the discovery of the power supply cause. Thanks Doug (W5WC)