Fixing Zenith CCII Avante 25JC49

[radiotvnut]

Originally Posted by zeno

If you havnt try a WTB on the AR site also. So many of these sets were
built so there has to be an ECG sub. Used is possable also but I
wouldnt touch one thats cracked, bulging or discolored !

That white crap I have seen before. Seems to be harmless but wouldnt hurt to gently knock it off.

FBT's were 99.9 % reliable. If you look at the 4 tube hybrid, flat SS chassis,
& the CC2 I did 2 on hybrids ( BIG kits), none on flats & maybe one
on CC2's. Dont get better than that !

73 Zeno
LFOD !

The only time I've ever seen a FBT fail on any pre-System 3 solid-state Zenith color is when the tripler shorted and took the FBT and HOT with it (likely caused by the customer constantly resetting the breaker in rapid succession). I don't recall seeing a bad FBT on the first-generation System 3 (9-153 module), but I've seen plenty of arcing/bad FBTs on the 9-160 modules.

As far as the tripler in the OP's set, I think that's the one with 5 terminals, and I seem to remember that the ECG sub would not work (it would trip the breaker), and an OEM part may be in order here.

I didn't really care for those CC2 sets with the EFL tube. The triplers in those would short the HV to the focus lead and burn up the CRT socket, and in some cases, ruin the tube.

[drwatson32]

Originally Posted by radiotvnut

As far as the tripler in the OP's set, I think that's the one with 5 terminals, and I seem to remember that the ECG sub would not work (it would trip the breaker), and an OEM part may be in order here.

Yes, unfortunately it's that 5 terminal one.

[jr_tech]

AR site:

https://antiqueradios.com/forums/index.php

jr

[drwatson32]

Originally Posted by jr_tech

AR site:

https://antiqueradios.com/forums/index.php

jr

great, thank you

[drwatson32]

Like a nutjob, I snagged what I believe to be the correct paperweight to go with my giant paperweight. Joking aside, I remain committed to finding the tripler and getting this set working again. Here are some pics for the curious. I thought it was kind of funny how the PCB interfaces with the buttons with the same push-on connectors as the modules in the set. I can hear the power button, channel hi, zoom, and volume buttons. My phone registers the tones as being upper 8khz to mid 9khz. The other buttons seem to do something as my mic gets overwhelmed and shows 100db of all frequencies when I hold the remote right up to the mic with buttons pressed. Might be outside the response of the mic. I won't be able to test beyond this till I can power the set up again.

It's half tempting to fire this up again to see if I can witness what exactly went. I hate to break more things. Maybe worth disconnecting the flyback from the tripler to isolate that as being problematic? I have feelers out for a tripler but so far no luck.

Side note, I get 10ohms across the oil capacitor, but with it still in circuit.










Here, I noticed the ground strap from the aquadag cover (is that what we'd call it?) to the power supply board was baked by an adjacent wire wound resistor. The insulation is crispy now, but I pushed these apart from one another. Guessing this isn't of much consequence, but thought I'd throw that in here.

[drwatson32]

As an update, I managed to find a NOS ECG561 tripler for a fair price. I still don't even know 100% that is crosses, but the appropriate amount of terminals are there. Do these hold up any better/worse than Zenith parts?

I just applied silicone to the input pin and will wait until tomorrow night to try powering it up.

As a side note, I managed to snap in half the clip that covers the focus and control pins when trying to reinstall it. I figure nothing is done without a reason, should I silicone these wires given that the cover broke?

[Alex KL-1]

Originally Posted by drwatson32

Like a nutjob, I snagged what I believe to be the correct paperweight to go with my giant paperweight. Joking aside, I remain committed to finding the tripler and getting this set working again. Here are some pics for the curious. I thought it was kind of funny how the PCB interfaces with the buttons with the same push-on connectors as the modules in the set. I can hear the power button, channel hi, zoom, and volume buttons. My phone registers the tones as being upper 8khz to mid 9khz. The other buttons seem to do something as my mic gets overwhelmed and shows 100db of all frequencies when I hold the remote right up to the mic with buttons pressed. Might be outside the response of the mic. I won't be able to test beyond this till I can power the set up again.

It's half tempting to fire this up again to see if I can witness what exactly went. I hate to break more things. Maybe worth disconnecting the flyback from the tripler to isolate that as being problematic? I have feelers out for a tripler but so far no luck.

Side note, I get 10ohms across the oil capacitor, but with it still in circuit.










Here, I noticed the ground strap from the aquadag cover (is that what we'd call it?) to the power supply board was baked by an adjacent wire wound resistor. The insulation is crispy now, but I pushed these apart from one another. Guessing this isn't of much consequence, but thought I'd throw that in here.

Intriging, this remote control is sonic (audible) or ultrasonic system? In case of ultrasonic, the ultra small MEMS mic from cellphone can be confused with high amplitude ultrasonic signal.

[zeno]

Zeniths ran somewhere between 30k & 40K. Ultras went away
apx 1980. they got them to the point of having full key boards with
near 20 buttons & made them very reliable. I dont remember any being
triggered by random noise like shaking you keys or the dog scratching his neck !
Zeno