Hi Michael
I confirmed in my shop notes, I did separate U550 and T550 by breaking the connection at T550 pin 10. After doing so F558 blew upon powering up the scope. I was looking at pulling U550. Still working on figuring out Which board connections are which. Looking at the schematic it appears that there are 11 connections on U550. The schematic just shows a box for the multiplier. Where did you find the specs for the multiplier circuit components. Should I expect that if I build a multiplier and install it with the existing U550 I should see that multiplication in the readings and thus perhaps rule one way or the other on the multiplier and go from there? I have 6.8V at the junction fo CR582 and C582. I think there should be 90 to 95V there. What drives that output of T550 (pin 2). Or should I see that fact in itself as an indication the T550 is shorted and concentrate there before tearing into U550?
Harriosn
