No Heater Glow in 2006 S.E.X. [resolved]

[duman]

--Revised to remove attachment - Sorry!!

Greetings from a happy S.E.X. owner since 2009, currently powering pair of Klipsch Forte I's.

Over the past few months, I'd be playing music and suddenly the music would stop.  I look over at the amp and the filaments are no longer glowing, as if the amp is off.  Usually, switching the amp off and back on will bring back the glow, but occasionally it does not.

At one point after experiencing the above, I did the resistance measurements and everything seemed to check out.  However, the voltage readings were out of whack.  Referring to the attached circuit diagram, which is marked up to specify the corresponding right channel terminals:
terminals 1,2,4 - 236V
terminal 6 - 472V
terminal 11 - 445V
terminal 16 - 438V
A2 - 435V (second stage plate)
A5 - 423V (first stage plate)
Also, A7 and A8 (defining the potential across the filament) were both 0, although C2 (which I expected to have the same potential as A7) was 6V.

Left channel values were similar.

At the power transformer:
T1 - 118VAC
T2 - 0VAC
T4, T5 - 6VAC
T6 - 522VAC
T7 - 521VAC
T9 - 522VAC
T10  -521VAC (T6 through T10 are quite different from the specified values, but about 100V more than the values I measured upon initial build)

Plate Chokes
Right
T1,8 675VDC
T4 640VDC
T5 660VDC
Left
T1,8 1030VDC
T4 1065VDC
T5 1030VDC

Any thoughts?  It's been working perfectly for years.  Possibly a component gone bad?

Thanks for reading!

p.s. while confirming the above measurements, I ended up shorting one of the  +1000V autoformer terminals to the rectifier portion of the DC heater supply, blowing two of the Schottkys.  So now I have two problems to deal with....

[Adrian]

Posting BH schematics is not allowed.  This will probably be removed.

[Doc B.]

Your voltages are way too high. There should be nothing over 400VDC in the amp. Either your voltage measurements are wrong, or there is something very seriously miswired in your amp. Don't power it up again until you have determined what is going on. If you really are getting 1000V that can ruin many of the components in the amp.

Could you describe how you hooked up the meter to the circuit in order to measure the AC voltages at the power trsnaformer and also the high DC voltages?

[duman]

My apologies to Doc for missing his follow-up question to my original post.  I read it in my browser and his question must have been cut-off.  I appreciate the offer of assistance!

Closing off the topic, I rebuilt the DC heater supply and everything is working perfectly again, with in-spec voltages. The sound seems improved as well.

Looking forward to a Stereomour II at some point!