Flyback Failure

[nasadowsk]

I've got Sparton I'm trying to get rolling now - I can't get HV or vertical sweep. No vert is related - this set's vertical section is 'slaved' off the horizontal's boost B+. The horizontal also steals some boost too.

I can't get the 1B3 to light up (I have Bendix that sure can...) and at best, the HV at the CRT suction cup is a rip roaring 4kv

There's at least some drive and the set sounds like it's trying HARD - the horizontal's got a LOUD whine to it. Real loud.

The flyback's not open on the HV section. At the AGC pulse winding, I'm seeing 200v pulses. The yoke's not shorted as best as I can tell.

I'm thinking It could be a shorted damper - was the 6W4 known to be flakey? Otherwise, barring a major problem in the vert section that's loading the boost heavily , I can't seem to find anything that's blindingly obvious.

Naturally, the schematic doesn't show a boost voltage - the main power supply's best is 340 - and it's surely there. So, I'm guessing I should see a boost far higher, but no idea how much.

I'm stuck - the flyback looks fine, but I can tell SOMETHING major happened in this set - the 5U4's filliment was broken when I got it, and looked burnt in a few spots. There's very little besides the sweep that the 5U4 powers (a 5Y3 runs everything else).

I'm stumped here guys I want to think it's not the flyback or yoke, but barring a damper or vert section issue, I'm out of ideas