I figure after 2 weeks of the CTC-7 kicking my ass all over the place, it's time to ask for a little help.
Here's the deal:
About a month ago, the screen would randomly start going blank. Sometimes after a little playing, sometimes right away on startup. Then one day, there was no getting it back. 2 weeks ago, I decided to pull the chassis and do some digging. As I suspected I had no signal through the video amp, causing a blank raster. First thing I did was inject a signal right into the 6AW8 first video tube to see if there was any trouble with the video amp itself, but it passed the signal just fine all the way to the CRT connector. I did this by lifting the E terminal on the board, and attaching the NTSC gen through a coupling cap.
Next, I reconnected the wire at point E and read voltages. Come to find out, the video amp tube is being completely cut off any time the E terminal is connected to the IF strip! I get -22 grid volts where I should have +21, and the cathode is sitting at 2 volts instead of 23.
I left the E terminal disconnected and looked into the IF strip, where more funky readings showed up. 1st IF has nearly 200 volts plate where it should be 110, 2nd has same, 3rd is at 80 when it should be 150. Similar story with the screens. I can't figure it out! It's like the first 2 IF's are cut off, 3rd is on hard, then 1st video is cut off. No explaination either, every single part I sub/check comes back fine. It's gotta be something in common with all of them, right? It's not bad grounds, I've resoldered all of them in desperation.
