Completed Tweedle Dee with nasty short - HELP please

[PboBSG]

Hello newbie here! I realize this thread is cold (originally posted to an existing thread - a kind sole suggested I cut and paste to a new thread for help) and everyone but me has probably built a Tweedle-Dee but I'm at a loss where to go for information.

I have a tweedle-dee on my workbench, completed but there's a nasty short once the rectifier gets warm...about 30 seconds and current limiter goes full bright. Funny thing is that I have built 3 Tweed Deluxes, 1 tweed Bassman, 1 Tweed Bandmaster and never had an issue. But, I'm stumped.

I use Rob Robinette's start-up procedure, I use a current limiter plugged into a variac and I have rolled a number of new and used rectifier tubes can't find an issue with the tubes.

Tweedle-D Schematic (2).jpg

Clayton Tweelde Dee 20250129-5.jpg

Clayton Tweelde Dee 20250129-4.jpg

Clayton Tweelde Dee 20250129-3.jpg

Clayton Tweelde Dee 20250129-2.jpg

Clayton Tweelde Dee 20250129-1.jpg

I have pulled the first 33uf filter cap and tested it, replaced it, tested that one and still 30 seconds after the on switch the current limiter is lighting the shop.

I haven't posted pics here before, if I have done so incorreclty please advise the proper procedure.
Thank you kindly in advance.
Rich

[martin manning]

With all tubes removed and caps drained check resistance to ground from the filter cap positive leads and from the power tube cathodes. You should see tens of thousands of ohms on the filters and 250 ohms at the cathodes.
Check the resistance from the power tube grids to ground. You should see 221k.
Install only the rectifier tube and power up. Check the voltage at the power tube grids, at the junction of the 220k and 1k5. You should see 0V.

[fred.violleau]

Hard to see on the pictures, but I assume you put an insulation board under the board holding the components?

I would start with testing every point where HV goes in the board for a short.

Fred.

[Colossal]

Along the line of Fred's question, you may also want to check to see if you have a blob of solder from an eyelet touching the chassis.

[PboBSG]

Thanks for the feedback, much appreciated. I do have the insulation board under the component board I will have to pull them to check for issues underneath beyond that.

My next course will be to check resistances as suggested.

Thanks again!