Here are the input signals at C1 on board A5:
The connectors are underneath.

 

It looks like 18 and 17 delay line of A5 pcb is the main connector going from the
Vertical amp and vertical preamp is that correct?

 

just your your image of 18 and 17 . I will probe these two now

 

Look around. The delay lines are coils of coax cables.
Before we move any connectors around let us see if we can pin point where is the bad connection.

 

I just probed the two
the image on the tek47a looks normal square wave. looks good at point #4 and #6

 

Edit: Ignore this for now having read your latest post.

[Here is a stab in the dark.
C3 is shown in the schematic as 4.7μF with *Optimum value selected at factory, typical value shown.

I believe this the orange-red capacitor shown in the upper right of the photograph.

I would be inclined to replace this with something similar.
It might be easier to clip off what is there, leaving as much as the old capacitor leg as possible and solder the replacement on to the old legs.]

 

I went back and checked pin 18 of the ic chip and it looks good as well

nice square wave on the tek475A at pin 18 of the ic chip

 

Can you point out on my upload image C3?

 

I need to correct post 87 and 85.
I had the tek475a set on chop mode and that gave the wrong image.
When I set the tek475A back to channel 1 the bad image reappeared

so #4 and #6 of post 81 show the bad image of the post #1
and pin 18 of IC chip also show the bad image of post #1

 

How can you get at A5A1 if it is hidden under the metal bar?
Can you probe pin-10 as well as pin-18?

Why do you think what you are seeing now is different from what you reported in post #60?

What IC chip? Are we sure we are referring to the same thing?

 

Ok, we're cross posting here. We ought to slow down but I can feel the excitement because I think we are closing in.

 

Well there are 9 pins located on or near A5A1 . Both on the top and bottom

you are right the IC large white IC located "out of your view" sets in the board resessed. and those pins are on top of the A5 pcb

 

Hold on, I'm on to something.
Sorry, I've changed my mind.

 

So far let me sum it up

All the test points we have tested, all test with the bad signal image.
this is with the Tek475A set on channel 1 button

If I was to use the chop mode button, that would give incorrect readings
I made that mistake

 

I understand.

Just to confirm that we are on the same track. Can you test these two points?
The signal should be the same as pins 10 and 18.

 

So the test points on #42-43 post were all done with the Tek475a in chop mode.

that gave me incorrect readings. When I went back to tp9 with the oscope set on
channel 1 . these reading looked bad like the one in post 1

 

Just to confirm that we are on the same track. Can you test these two points?
The signal should be the same as pins 10 and 18

yes I will do that now

 

Just to confirm that we are on the same track. Can you test these two points?
The signal should be the same as pins 10 and 18

just did it and they test bad.

 

So 97 posts later and we are back to square one.

What do the signals look like at TP9 and TP10?

 

identical sorry same bad image