Ctc9f

[Reece]

I've still got one of those long skinny fiberglass screwdrivers, yellow handle, green shaft. The tip doesn't last long and has to be reground. It ought to have a metal or some kind of hardened tip.

[Charlie]

Dammit!! Turned on the set today and had extremely weak video and audio. The set has been playing perfectly.... and now this!

I am leaving early in the morning to fly to Singapore to join the ship. I am supposed to be packing and preparing to leave... I don't have time for this crap... however I can't turn my back on this. I am easily distracted... especially when it comes to TV's.

I pulled the back off. After pulling some tubes along the picture chain, I found the 1st IF to be bad... think it was gassy. I put it in the tester... couldn't see the heater light up, but felt heat from it. Never moved the needle on the tester. Also, found the video output tube to be very weak (these tubes were alll good a month ago) and replaced it.

Now, I have good audio, but video is dark with horz lines. I find if I slowly turn down the AGC, pic will fall into sync, but poorly and with no color. The point in which I get a picture on this adjustment is well below where the setting was previously. Also, if I slightly pull off the antenna lead, picture gets better.

At this point, I feel that the picture detector diode crapped out. Current sympton is the same as Fujifrontier had on his Philco... we changed that diode and fixed the problem. I think I've got the same problem now. I'm not happy.

I don't really have time to pull the chassis to comfirm. Like I mentioned, I'm supposed to be getting ready to leave before the sun rises. Looks like I will have to wait till I get home in early-September to check and change this diode.

Why do these things happen at the worst possible moments?

[DaveWM]

sounds like AGC, maybe the filter cap on the AGC opened up? .22

also sub in a 6EA8 noise inverter (that one you can do before you leave, its on the audio board)

as far as why now, well because it can

Take care on trip/work

[Charlie]

AGC is what I meant... have too many things on my mind today. Had changed a 1N60 in an AGC circuit on another set to get it going and figured it was the same issue here. Funny thing is... I think it seems odd to have so many failures show up all at once. First IF, video output, and now something in the AGC. Kinda weird I think.

Yeah, I can go try a 6AE8... the back is still off.

[Charlie]

Damn... that was it. Popped in another 6AE8 and now it's back on! So three tubes went south... all at once. Put the 6AE8 in the tester and found it had some serious grid leakage.