As I go through the pile of tv's I brought home the other day I come next to a GE C2 chassis, an 18" hybrid built in the fall of '71. (hey, so was I!) Just think, they could have bought a 4-tube Zenith but instead they bought this. Well, its not too bad.

It powered up without drama, it has color. First problem to tackle-I cannot turn down the brightness. I can turn the contrast, brightness, brightness limit, all the screen & drive controls down, and still the picture is at 'normal' brightness. The little troubleshooting chart in the Sams said to check Q305, the blanking transistor. This seemed plausible since I can see blanking lines clearly unless I ramp the brightness all the way up. Voltages there seemed okay but I went ahead & swapped it out; no change. I've swapped the video output tube, the voltages around there seem within reason, too. I don't understand the circuit well enough to know where to go next.

I guess U checked status of brightness and contast controls??? Not familiar with xistor circuits. Check both areas (bightness & contrast ) as have effect on brightness for possible faults. WOW , I have seen a hybrid set in ten years. The guy had a Zentih that didn't work. TV was his baby, even tho didn't worked. Probaly still sitting in his garage!!!!!!!!!!!!!

Familiar with solid state?? Keep this tv as most early solid states are thrown out already!!

:D

I have a 1975 GE 19" which is mostly tube type but has a few transistors...it is a lot like a Portacolor chassis with a bigger HO tube and damper...I can remember a brightness problem on it too and it seems like I replaced the brightness limiter pot with a new pot mounted on the chassis and this cured it...however mine had a lack of brightness. Its been a while though. Seems like a lot of the adjustment pots on these GE's can be pretty flaky.

The brightness pot & the limiter pot are in series going to ground, with the contrast control elsewhere in that little circuit. I bypassed the brightness controls with no improvement. Cutting the pots out of the circuit & putting in resistor substitution box the only difference I can make is to lower the contrast. It acts like something in some other circuit is causing this but I don't know what. I even tested the crt thinking maybe it was some sort of short there but no. I did replace the brightness pot finally as it was about shot.

I think that all the GE hybrid color sets after this used a similiar design. I have a GE svc.manual for one of the late models & it didn't look a whole lot different. I am supposed to be getting one of those sets soon; maybe I can do some side by side comparisons, provided that one works okay. I had one before & it occurs to me that it was too dark.

I would like to hold onto this one as it is a cousin of the big console we had when I was a kid. That one, of course, was a decent transformer set, while this, well, is what it is. But there are control panel similiarities & it just reminds me of the old beast.

Hey Bryan.I remember checking that set as it came from the auction house that was only 4 miles from my house(now out of business) last winter.The screen contols are open.All 3 of them which are encased in a single unit are open on the ground side.Therefore you aren't turning down the screen voltage when you're turning it down.Unless you can find a replacement you'll probably have to use individual replacements.Had a lot of problems with controls on early 70's vintage GE tvs.The Zenith Chromacolor II screen controls use to develop a similar problem of getting a burnt spot on the control except there when you tried to adjust the screen control it was either none of that color or full on of that color which was associated with the bad control.

If the damage is right at the end of the pot, some conductive paint might fix the open.

I think I would go with replacement pots...these screen pots on those GE's are 3 pots ganged to one mounting plate and they're puny and there is about 800 volts on those wimpy little pots. I think on my GE 1975 tube type set there was actually a problem with the drive controls as the blue would intermittently dominate the picture.

Thanks, JC! Now I can dig into it again. Think I'll try to rig up individual pots, got plenty of 'em in the junk pile. I'm having a good time playing with these sets. Right now I have the 15" Sylvania on the bench, setting me in fits with vertical problems. If I keep replacing caps & resistors I'm bound to fix it sooner or later.

Yeah.Glad to see your getting some of those sets going.They would still be rusting away in the shed if you hadn't gotten them.Fixing modern junk runs me ragged.Good job on the Motorola.I had that set sold to someone in the late 80s before I got my foot in the door of a tv shop and really started learning.At the time I was picking up junked tvs and fixing as many as I could up and sold em' to make side money.Most of them came from a tv shop long gone out of business.He gave me all the old sets that he didn't want to fool with.I was working at English's restaurant as a dishwasher and line cook and boy did I really need the tv money to pay my car payments in the wintertime.Anyway it came back for the width drawing in and out intermittently and I traded her a 19" GE EC series solid state set that I had thoroughly soldered the on board griplets.That set was one of the 1st to use a double sided board and the griplets that joined the traces on each side were a big source of intermittents.Never heard a peep from her so I must have did a good job.Started to dig into the Motorola but it ended up being put aside as more lucrative projects came along.Don't remember why most of tubes were taken out.Must have had some other set that needed tubes or something.The tube should have all the life it had in 1988 because it ain't been fired up til you worked on it.You're bringing back memories.Looks like you found the problem that I didn't fix. :o A poorly soldered width coil.Didn't have much better of a picture then.But I think the tint contol worked then.Keep at it.I'm sure you'll get those sets going.By the way another shop owner in Salisbury retired a year before and I got a lot of stuff from him.He has some old tvs in his shop but someone else got the roundies and really old tvs. :(