Ok I got big AC signal on pin 2 of T-605 with the isolation tranny hooked up and scoped and the only AC signal on the other side was small on 10 & 11 so does that whole other side get rectified for each pair of windings. 5&6 / 7,8(ct)9 and 10 &11 ?

So I should get DC at all of those rectifiers right and the ground reference would be the cold gnd or pins 3 & 4 of connector 641. This whole thing sounds like an open ground because the whole supply at CN-641 has no voltage at all.

If you have AC on T605 pri you get your B+ UNLESS its to small,
way off freq, or there is a short. I may be wrong but I think they ran
around 30kc with 2oov pulses. I do remember the training manual said
the waveform had to be perfect. You say the IC runs hot, check
for shorts on the secondary especially D648 ( lift it).
Beyond that you may need some outside help & I can give you
some ideas on that.
BTW manual has no waveforms but the Sams manual prob. does.

73 Zeno

I removed T-605 and put a small 10 VAC voltage on the primaries and it blew my 8 amp variac fuse. Do you think it's bad or is my transformer test not a valid one ? All of the trannys I use operate the same way is there something I'm missing.

Pulled D648 and it won't give me a diode drop like it's open I'm reading 3.8M on ohms reading so It's not shorted but could be bad ?

Good idea BUT switchers run at high freq so if you use at 60hz
it sees a dead short. See if it works with D648 out.
I understand SMPS' are difficult when you have done tube audio. It
was always the hardest thing for me to fix. Some have a wicked high
parts count & near imposable to understand. Add to that Sony is
the only one doing it this way & every one I fixed was an obvious
fix.

You may consider joining repairworld.com. They cover everything
and may help you in your regular work also. Thousands of tips
catagorized by make/model. Also you can post problems.
A few tips will pay for it fast. Dont forget to search similar
models.........

73 Zeno

So even with the tranny out it won't test like a regular transformer ? So if I sent say a 30k 10 volt signal to it then it would work ? How does the transformer know what frequencies it is supposed to see ? Do appreciate the help Zeno and just trying to grasp this concept. ha !

DC wise its the same & works the same. You can check continuity
the same. If you know what freq it is designed for yes you could do it
that way. But the farther you go from that freq the more current it
draws & eventually it is seen as a short.......

Look at an amp. Output xfmr made to pass say 20h-20kh.
If you could get say 50kh through it the 6L6's wouldnt like
it & would glow cherry red & meltdown. Same idea. Go to
the secondary & it says "use 4-8-16 ohm spkrs". Use a 400 ohm spkr &
you barely hear it. Its not really ohms DC wise, but impedance. How things behave with AC & complex signals. Beyond that we get into engineering.
I wont go there, its better to look like a fool than prove it to all !!!

Oh yes, how the xfrm knows. its in the core material, windings,
spacing etc...........

73 Zeno

Thanks Zeno and yes the EE part is mind-boggling tstl when you start getting into the formulars in the complex domain. Transformer lingo can get as hairy as you want to make it and I've seen and done a tad and it's not any fun but to an EE may be but I'm not one of those and don't want to be !!

I'll try to get to that site and see if those cats can help me out. TIA,

KB

When you go to repair world remember they are mostly like us
making a living at it. So a quick intro is in order otherwise if you
say something wrong you will get bitch-slapped & many wont help
you.
Start the question from original problem & keep things in order &
simple.
And keep that tube stuff going, its all I will use for HiFi. Especially
appropriate since I got nothing but 50's records.....
Good luck & let us know what happens.

73 Zeno

Your a class act Zeno thanks I'll let you know what happens. It will be Monday before I start as a busy weekend ahead.

Tubes are definitely the way to go and I'm also in a band and play guitar so yeah it's all tubes haha!

Class act ! Never been accused of that before.......
Give my parents the credit, not me.

BTW One other thing to keep alive. You used the term "cats"
I thought I was the only one using it left. Once my son had a few
pals over aged 18ish. I was chewing them out about something
( beer prob ) & said "you cats bla bla.... They were baffled &
laughed at me. Then one of them started insulting my Fisher
stereo tube amp. Not a good idea hooligan punk. I whipped out a mint DJ copy of Anisteen Allens " Fujiyama Mama" ( capitol 1955) & played it LOUD.
They were awe struck. Never heard audio like it.............
I guess I showed them cats !

73 Zeno

I got an old Fisher SA300 that I put UL OT's in and it sounds awesome and just so unique and warm. The new gear has better quality and cleaner but the tone from those amps is stunning especially when you crank it . Glad you set those cats straight !!