Last Attempt To Find Tech To Help with Avante
 

Okay, I've tried all I can to remove the jailbars from my Avante. I need to find someone in the Los Angeles area that can help. If anyone knows of someone that can help, please let me know. If someone can help fix it, I will give them my scope and B&K for their trouble. Both units are in excellent working condition. They've just been sitting around after using them to try and fix my issue. Don't have a use for them anymore.

http://videokarma.org/showpost.php?p...39&postcount=1

Sometimes I think of this problem believe it or not. It will probably
haunt me till I die.

One thing I wonder about it is had the tripler replaced by an ECG etc.
Somewhere with a scope you should see a big hoz spike then a trail
of smaller & smaller ones as it goes right then the next big spike.
It has to be seen on either the K's or G!, or G2. With zero signal, not even snow it has to be there. Hmm 1000 V boost filter ?

Another sleepless night.

73 Zeno:smoke:
LFOD !

BTW did you try Shango or Jordan Pier ?

Shango?

shango066 on Utube.
He is what we call a "character" up here in New Hampster.
BUT he can work with junk & resurrect damn near any pile
of feces. Much to be learned from him, I have great respect
for his talents.

BTW be sure to have food & drink watching him.He can make
a meal out of a potato chip:D

73 Zeno:smoke:
LFOD !

I did change the tripler.

I have scoped so many circuits and found ringing, but if you look over some of my previous posts with pics, most said it wasn't an issue. I still think it is in the ABL as that gives a big ringing on the scope and jailbars seem to be a brightness issue. Also, with the inability to get the setup line to appear bright enough to use, I don't know if that is along the same line as the ringing, or????

I love this set, but every time a darker scene comes up, I'm reminded of the issues that still exist.

This is what I get on the ABL circuit.

The ABL runs off the reference pin of the tripler IIRC. Its the pin
with the big resistor & is just above ground to produce a small voltage
that varies with beam current.
With a good CRT as a rule G2 pots start to show a line at abt 1/3.
You need good boost IIRC between 800 & 1000 VDC. If thats OK
look back to to the G1 & K's. A bad boost filter will lower the boost
& leave unwanted crap on it.
I really suspect the tripler. Its the common link between the sets.
There are resistors, caps & diode stacks in them that may vary in
value from the OEM tripler.

enuf fer now, time for a beer. Or 2 or3............:beer::beer:

73 Zeno:smoke:
LFOD !

The way the tripler is in this unit seems a bit different than any I've seen before, but that could just be my limited exposure.

The trippler has an input and an output. The red output goes to the suction style cup on the CRT. That connection at the CRT has a second pink lead that goes from there down to a plastic distribution block. It then breaks out to two more leads. Once goes to the focus and the other attaches somewhere around the flyback and I believe then routes to the CRT socket. I could be a little off here as I haven't opened the set for a year and I won't be for about a week or so.

Okay, so it seems I didn't change the tripler. I remember now, after finding it in a box, that it didn't match what was in the set. The one in the set has an input, ground and output. The replacement has an input, ground, focus, CTL and output. I remember hearing a sizzling sound and it was coming from the plastic piece that is fed off the anode on the CRT and then it feeds the focus and???? Anyway, I found a new one of those and installed it and the noise was gone and I just assumed the tripler was working properly. So if NTE526A isn't the correct one, what is? Or, am I supposed to do away with that plastic piece with all the connections? I've attached a pic of the current setup, but note the plastic piece in the pic is the old one. I couldn't find a current pic. The tripler pic is one I found on the web, but it is the same.

Thanks

The replacement shown has the focus built in.
It is not a direct replacement at all but could be moused.

The OEM ? in the set uses the divider resistor, the plastic part
with the other big red wire etc.
If you go further with it get the ##'s off the tripler. If a ZENITH
OEM you should find part number 212-141-## on it.
Also be sure that big resistor isnt burned. Bad triplers sometimes
burned it.

73 Zeno:smoke:

Could that be a ECG 500A with the Zenith focus block ( HIDIV 3? )?

I will attempt to find the part number on it this weekend. It seems, according to the service manual, that there are two different units. One with the built-in divider and one with the external. The SM shows the integrated unit, but notes there are two different ones.

So I have choices, I can try to keep it original and find one that uses the external divider, use the one with the integrated divider, or if possible, use the one with the internal divider, but don't use the integrated part and run the external divider.

Thoughts?

According to the service manual, it is 212-142-01. This one is noted as tripler only. The other part number is 212-141-01 and is the tripler with focus bleeder combined. It says to see schematic, but the schematics show the combined tripler, which is not my setup. Either way, most cross-references I can find point to the combined (NTE526A). I did find a site that has a PDF of and old Zenith list of universal triplers and it has (977-46) as the simple tripler replacement. No such luck finding that.

So I either install and ditch the external focus divider, use it with the external divider by ignoring the outputs on it, or I continue my search.

Going by this pic I located, I'm going to assume the tripler has already been replace sometime in the past. It doesn't look OEM from '74. Kind of looks like the simple version of the replacement I got a few years ago (NTE526A). Same kind of grey plastic, tan resin and molded bracket.

Also shows the new focus divider I installed.

Oh, and a question.... Is the crap on the leads for the tripler covered with simple RTV, like you'd use for car gaskets, etc.?

About the jailbars, I remember a similar problem many years ago that ended up being a lead dress issue. The yoke and convergence wires had to be kept away from the CRT socket cables, especially the yellow wires.

I think Jon in Halifax had one also & took a pix of the lead dress on his.
It was untouched & still had the OEM wire ties. Its a good point though,
I have run across dress problems where the yoke wires got too close
to the CRT cathode lines & caused it. History is I had 2 of these back in the day.
In both cases the HV was worked on but the customer didnt want to pay
the extra to look into it . 30 yrs later 2 or 3 have popped up on the forum
but nobody has found out why.

The tripler in the set HAS been changed IMHO also. Zenith never
used piles of sealant like that. Dont know exactly what it is, we
bought little tubes of it p# 205-229. They also come with new
triplers.
Anyhows for now get all the numbers off the tripler in the set & we
will take it from there.

73 Zeno

Well I opened her up and took some pics. Don't know if the tripler is original, but it does have the Zenith PN on it. Also, attached pics of the goop on the tripler and flyback leads as well as the yoke/convergence wiring. The wires were routed the way you see by me years ago in hopes of fixing an possible interference, but it was of no help.

See the pic I just attached about the wire routing.

See the pic I just attached about the wire routing.

Here is what I see. The tripler is OEM. The date code ( 7314 ) puts
it in the range of the set being born with it. It also looks very clean.
Often they discolor or swell up when stressed by HV problems.
BTW did you change the hoz out. Its not original. There is a low ohm,
1.5 ohm IIRC & a 'lytic in the base circuit. The resistor should be a carbon or another non wire wound.

73 Zeno:smoke:
LFOD !

Yeah, I replaced the HOT. During the scoping for the jailbars, I shorted it. I am not sure if it was the original. At the time of death, I was unable to find an OEM, so I went the NTE route. Seems to be working fine, but I have a lead on an OEM if that is a better choice.

As for the "base circuit" I'm assuming you mean the for the HOT? If so, under it is a 600K 2KV capacitor and a diode. That's it. If not the circuit you're referencing, let me know.

Okay, I don't know where to go from here. I'm assuming the tripler is okay, and so is all I've found. Guess she goes back into storage.

Thanks for the assistance.

One last chance & if it still exists it would be good for many
of us.
Back 10-15 yrs ago there was a parts distributor (IIRC) that
ran a huge database of TV, VCR, audio etc problems, mostly dogs.
You could drill down with model, chassis easily. IIRC members also posted
OEM bulletins. We subscribed to it & it paid for itself in a few weeks.
Trouble is I cant remember its name !
I am sure someone on the list also remembers it. If its still out
there it would be great to find.

73 Zeno:smoke:
LFOD !

Hopefully someone will chime in.