My Brand New CTC-7!

[SwizzyMan]

I am very inclined to just shotgun replace everything but the ceramic caps in the horizontal and vertical boards. Resistors included.

[DaveWM]

you never responded about the 400v side only the 270v (204v).
You need to respond to each of my questions, in order, otherwise it is very hard to diagnose. I am asking these questions for specific reasons.

While its ok to shot gun replace paper caps, it is rarely needed for resistors.

You need to stay on track answer the questions as asked, then make the corrective actions in the order given. If not its pointless to ask for help.

[tvcollector]

Ceramic disk caps usually don't fail.. And it's only a handful of resistors that fail.. Shot gunning components that don't need to be replaced only gives you a higher chance of messing something else up.. Some people may choose to replace the electrolytic cans even if they are fine, and some people even replace the film orange drop caps on the critical area such as the sweep board.. Going and trying to replace every component in a set is not a good idea at all...

[SwizzyMan]

Originally Posted by DaveWM

you never responded about the 400v side only the 270v (204v).
You need to respond to each of my questions, in order, otherwise it is very hard to diagnose. I am asking these questions for specific reasons.

While its ok to shot gun replace paper caps, it is rarely needed for resistors.

You need to stay on track answer the questions as asked, then make the corrective actions in the order given. If not its pointless to ask for help.

Oh yes sorry I will check that asap.

[DaveWM]

another helpful tool in remote diagnosis is pictures. lots of pictures, pictures are worth a 1000 words. that way I can see what you are working with, the condition of the parts, etc.. lets see the caps you have still in stalled, what you have done so far etc... its hard to keep up.

so start with a recap of things done to date, a list, that will help. Long threads like this can be hard to follow.

when adjusting controls or diagnosing image problems, video is better as you can see the dynamics of the condition rather than snap shots from still images.

The hardest part I have in diagnosis is having to rely on someone else description of the problem, everyone sees thinks differently so verbal descriptions of a problem can be completely different for the same thing.

[SwizzyMan]

Originally Posted by DaveWM

another helpful tool in remote diagnosis is pictures. lots of pictures, pictures are worth a 1000 words. that way I can see what you are working with, the condition of the parts, etc.. lets see the caps you have still in stalled, what you have done so far etc... its hard to keep up.

so start with a recap of things done to date, a list, that will help. Long threads like this can be hard to follow.

when adjusting controls or diagnosing image problems, video is better as you can see the dynamics of the condition rather than snap shots from still images.

The hardest part I have in diagnosis is having to rely on someone else description of the problem, everyone sees thinks differently so verbal descriptions of a problem can be completely different for the same thing.

I will be gone for the 4th of July weekend but when I get back I will do plenty of pictures and videos.

[SwizzyMan]

Ok pulled it back out. Stupid wax is dripping everywhere! Ugh! I was able to measure the 385 v B+ and it came out at 384 v. Took some pictures for reference and so all of you can see what I have done. http://imgur.com/a/oTaRJ#6MoKAI0 scroll down towards the bottom to find the ones I just took.

[DaveWM]

ok so the B+ is dropping too much across the two 1600 ohm resistors that drop the 385v to the 270v (you get 205 IIRC).

start by checking the resistance of those paired resistors (800ohm, let the meter settle down).

If the resistors check out there maybe a leaky 50uf that connects to the 270v side I would start with checking that for leakage at the rated voltage.

You need to get the power supply voltages right before trying to further trouble shoot the lack of vert deflection.

[SwizzyMan]

Originally Posted by DaveWM

ok so the B+ is dropping too much across the two 1600 ohm resistors that drop the 385v to the 270v (you get 205 IIRC).

start by checking the resistance of those paired resistors (800ohm, let the meter settle down).

If the resistors check out there maybe a leaky 50uf that connects to the 270v side I would start with checking that for leakage at the rated voltage.

You need to get the power supply voltages right before trying to further trouble shoot the lack of vert deflection.

Can't seem to find those two 800ohm resistors. Where are they located?

[DaveWM]

two 1600 ohm in p should be 800 ohm total look at the schematic, it drops the 382v to 270v the 382v is at the output of the filter choke and 80uf filter cap.

from there you should see two 1600 ohm resistors, prob large WW types.

[Phil Nelson]

They are R104 and R105 in the factory schematic, each rated at 10 watts:



Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[SwizzyMan]

Originally Posted by DaveWM

two 1600 ohm in p should be 800 ohm total look at the schematic, it drops the 382v to 270v the 382v is at the output of the filter choke and 80uf filter cap.

from there you should see two 1600 ohm resistors, prob large WW types.

One read 809 ohms the other red 810 ohms.

[DaveWM]

well they are connected in p so will read the same value.

That clears the resistors as an issue.

Next if you do not have a cap tester to check 50 uf for leakage, you will need to disconnect it, temp tack in a new one and power up to see if that brings the 270v back up.

C104-b on the RCA schmatic (not shown on the clip from Phil) look for the 50uf section of C104 and check for continuity of the connection to make sure you are disconnecting the correct tab of the can. The schematic show C104-A, this is NOT the one.

you are looking for the SQUARE mark on C104 not the 1/2 circle.

[SwizzyMan]

Originally Posted by DaveWM

well they are connected in p so will read the same value.

That clears the resistors as an issue.

Next if you do not have a cap tester to check 50 uf for leakage, you will need to disconnect it, temp tack in a new one and power up to see if that brings the 270v back up.

C104-b on the RCA schmatic (not shown on the clip from Phil) look for the 50uf section of C104 and check for continuity of the connection to make sure you are disconnecting the correct tab of the can. The schematic show C104-A, this is NOT the one.

you are looking for the SQUARE mark on C104 not the 1/2 circle.

But isnt that a can with multiple values? So how could I just use one 50 uf?

[DaveWM]

disconnect only C104B the Square, connect the disconnected wire to a pos of a 50uf cap neg to ground.