At long last, a Chromacolor II!

[radiotvnut]

On your focus issue: I've seen this problem before. Usually, the control has to be rotated all the way to one end to get the best focus and it's still not a sharp as it could be. IIRC, the only components in the focus circuit are the HV tripler, the focus control itself, and the CRT socket. Either one of the three could be causing he issue. I've seen corrosion around the focus pin of the CRT socket. If there is no corrosion and there is continuity between the focus pin of the CRT socket and the focus pin of the tripler, the socket is OK. Also, check the focus pot for proper operation and make sure it's solder connections are OK. If that's not the trouble, you have a bad tripler. The tripler will run you $20-$30 and you'll have to look to find a new one as I don't think they are made any longer.

Concerning the popping you hear, check what everyone else said and also look at the HV lead that comes out of the flyback and goes into the tripler. From the factory, the input terminal of the tripler had a blob of RTV on it to prevent the HV from leaking. If the tripler has been replaced or if a technician removed the lead for any reason, he may not have used RTV to reinsulate the terminal. In most cases, it doesn't present a problem; but, it can hiss and pop during humid conditions.

On discharging the HV. Get a large value resistor, say 100K ohms and connect one end of the resistor to the CRT dag ground via clip lead. Connect the other end of the resistor to a screwdriver. Hold on to the insulated part of the screwdriver and slide the blade under the anode cup. It might spark a little; but, you won't get shocked as long as you hold the insulated part of the screwdriver. You can do the same thing without the resistor, but the discharge will be more "active"

[radiotvnut]

The chromatic button presets are usually accessed through center holes in the custommer control shafts.

[marty59]

Originally Posted by MRX37

That's the whole reason for my hesitance. I have never discharged one of these things, and before suggesting I use a screwdriver to discharge it... No.

This is where the one hand behind your back rule applies!!

You can use a bleed-down resistor as mentioned, or I have a long, skinny screwdriver that I attach my 'gator lead to going to chassis ground. Sometimes with a bleeder resistor in there you'll not hear that you've made contact. Discharging electroytic caps, by all means use a bleeder (with a meter to monitor- lot'sa current). I can understand your hesitance! Just slide that 'driver under the cup and listen for the "snap". You'll be okay!

If you're still hesitant (understandable!) then apply the buddy system and have someone present with you. Once I got over that initial fear myself then I realized that it's not a big a deal..really!!

But you've got to get that plastic/gooey flap pulled up out of your way first so you can see what you're doing.

And kudos to you about wanting to be safe. We're limited to ways of discharging CRT's. And, if there's still a TV guy in your area (or one of us) don't hesitate to have him show you.

[MRX37]

I can get perfect focus, it just means rotating the knob all the way one way.

I think I'll tackle the goop cleaning next Saturday or Sunday. In the meantime, it's going to sit unplugged.

Could I discharge the anode cap to any available ground (outside of the TV) rather then the CRT dag ground?

[marty59]

Originally Posted by MRX37

Could I discharge the anode cap to any available ground (outside of the TV) rather then the CRT dag ground?

No,
That CRT is nothing more than a big, glass capacitor! You 'gotta get across it. Tie your ground lead to the chassis somewhere near the high voltage section or better yet, that chassis bracket that fastens to the CRT mounting. On some sets, you may see a label that instructs you to discharging points.

If it makes you feel better, you could run a ground lead from the set's chassis (or that CRT mounting) to an earth ground "also" but it's not really necessary or standard procedure.

[MRX37]

Okay. How big of a resistor would I need? 1 watt? 2 watt? Bigger?

My guess is that I can rig up the resistor between the anode cap wire, and the metal bracket that helps hold the CRT in place.

What I might do is connect one wire to the anode cap, wire connected to the resistor and screwdriver, then touch the screwdriver to the metal bracket that holds the CRT...and pray that the resulting spark doesn't make me jump too much.

[radiotvnut]

I'd get the highest wattage resistor that I could.

You'd do better to clip one end of the resistor to the CRT ground and attach the other end of the resistor to the metal shaft of an insulated screwdriver. While holding the insulated portion of the screwdriver, slip the blade under tha anode cap. This will be a safest way.

[MRX37]

Originally Posted by radiotvnut

I'd get the highest wattage resistor that I could.

You'd do better to clip one end of the resistor to the CRT ground and attach the other end of the resistor to the metal shaft of an insulated screwdriver. While holding the insulated portion of the screwdriver, slip the blade under tha anode cap. This will be a safest way.

CRT ground would be the same as that metal bracket that holds the CRT in place right?

I really do NOT want to do it that way, but... well if I learn how to it'll give me much more freedom when repairing or taking apart a TV... probably not a bad thing to have if I'm going to make use of a 34 year old set for any length of time.

[radiotvnut]

It should be. Just trace those large ground straps from the CRT socket to where they clip on the degaussing shield and use that as your ground connection.

[MRX37]

Okay. I'll tackle this job next week.

It's got a lot of oily gooey stuff on some plastic shield that covers the anode cap. I have some goo gone which I plan to use to remove all the goo.

Might practice discharging the CRT of a computer monitor that I don't need. That way I can steal its anode cap if I need it.

[andy]

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[MRX37]

Just an update. I'm not getting to it this weekend. Too much other stuff going on.

[MRX37]

Looks like I lied. I had some time to open up the TV. The anode cap looks pristine. I don't think I need to go mucking about with it, which is fine with me because discharging the CRT is still a HELL NO!! situation for me.

I'm cleaning the goop off of the plastic anode cap cover, and going to clean up any goop I find. Tripler seems to have a big black blob of sealant where the flyback wire enters it. (silicone sealant maybe?) Looks fairly recent, perhaps the tripler was replaced at some point in this sets life.

Actually come to think of it the anode cap and wire also look pretty new. Here's some pics.




I think I'm gonna clean up the goop, then button it back up and try running it.

[radiotvnut]

The chances are very good that the tripler has been changed. Around here, it's rare to find a '70's Zenith with the original tripler. Unless, of course, the original tripler is bad when the set was found.

[MRX37]

Yeah, and it looks like the anode wire came with the tripler, so that's been replaced, so that probably means its connection to the CRT is fine and not arcing.

So I'm not gonna f*** with it.