I want a block diagram of standard CRT color TV?

Question

From that i want to see if it is TV tuner's fault when picture is distoted on every channel but DVD from AV in works normally.

Answer 1

You're on the right path....The DVD player's NORMAL operation tells me you have a good video path to your display, and the fact that ALL channels are distorted tells me it's your tuner.....

OR your Video Switch IC.....

Now the tuner uses 12v , 5v ,  and a 33v supply for tuning....

I'd look at that 33v supply, because the 12 and 5 volt lines are used everywhere else and those can't be bad IF you get good picture and sound on the DVD input.....

You make sure that 33 Volts is stable and doesn't drift by even one Volt !

Then, if your tuner ACTUALLY HAS  a pin labled Video and another labled Audio....

It has built-in IF circuit !  And if so, you can use your Scope to verify that the signal is, or is not Distorted !

If you don't....well I guess you can just throw PILES of money at the problem  and just buy a new tuner and a new Video Switch IC.....

Or you can pay a TV Tech to verify it, and OPTIMIZE the usage of your hard-earned money.

Can't help you with the Block Diagram since Answers doesn't let us PASTE PDFs to it.....