Hello all. I have a 75 Chromacolor II 25" console (i forget the chassis #) When its first powered up its fine, but after 30 minutes or so, the focus starts to drift. Within another half an hour the picture is a complete blur.

I don't have an HV probe for my Fluke, so I can't check focus voltages. The control has run out of rotation, and doesn't seem to do anything at all after the problem has fully reared its blurry head.

If anyone has an idea of where I can start, I would most appreciate it. This has been a faithful set that had a wonderful picture. There's no way I want to dicth it if I don't have to.

Thanks to all,
Jordan

Bad tripler? or maybe focus control pot?

bad tripler
ecg 526a or eqiviliant in other brands.
changed a bunch of em for this as these sets aged.
check the 4lead cap on the h.o.t heatsink to make sure it is orange.
if not dont play it till its replaced or bye bye crt!

I don't see a four lead cap at all. I pulled out the HOT heatsink and the only thing behind it were two disc caps that i think are 6pf at 2 killavolts (600k 2kv). They appear to be ok physically, but I guess replacement is a great consideration? The Chassis is 19EC45 if this is of greater help.

What is the purpose of that 4 lead cap? One of my other chromacolor 2 sets had one, but not this one. Too bad I trashed the set (ps short to earth). And why would it kill my CRT if not attented to? (don't worry, I havn't been using it, the screen is not ledgable)

BTW how much would a new trippler for this thing cost?
Jordan

Your set set did not have the four lead cap. Your set is a 74 model. Zenith had a major problem with their 75 models with a 4 lead cap that was used in the HO output.
When it would fail the high voltage could go way way up and break the neck off the CRT. Zenith lost a lot of money because of this part. The bad ones were a white or tan color. The replacement were orange and a sticker was placed on the rear or the set.

I remember that recall well. My Uncle was a Zenith dealer and we had to go on TONS of house-calls for that problem. I remember 1 set where the neck of the picture-tube did blow off due to that cap. Zenith paid for a tube for that set. That recall cost Zenith alot of money and was the beginning of their demise. I got a tripler from Moyers and it was around $27.00 IIRC. Also, I could be mistaken, but I think ALL Chromacolor 2's had that cap.... Also, concerning the focus problem, It's a safe bet it IS the tripler. I had a 75 Chromacolor 2 portable and it had the same problem. Discovered someone had done a "hack" repair job in the past and one of the high-voltage wires was spliced and wrapped with electrical tape! Could not believe that one.... Also, when I got the tripler from Moyers I bought a "cap set" that is also wise to change. They know what it is. Zenith had a part-number for them, but can't recall what it was at the moment... They were for high-voltage as well.

Will definitely by contacting Moyers. The set is very worth it. I originally bought it at an estate sale from the original owners. They hardly ever watched it, and it never had to be serviced. It has an "instant on feature" but they always kept it on a switch so the picture tube heaters wouldn't always be lit.

The cabinet looks beautiful, and the CRT tested more more than 90% emission on all three guns! they weren't kidding that it was rarely used. I will definitely be spending the 30 bucks to get it fixed..

Thanks to all for the info.
Jordan