My friend that gave me the '81 Magnavox came through today with this '76 XL100. This uses the CTC78W1 chassis, probably the last upright RCA chassis. I think the CTC68 was the newest upright chassis that I've seen. This set uses those pesky slide controls for tint, color, etc. The CRT was almost toast but responded to the clean & balance feature of my CRT tester. I've got audio and a raster with retrace lines that does not change as the brightness control is turned. Sounds like I need to troubleshoot the video circuit.

I used to see many of this style chassis back in the '90's. This is the first one I've had in several years. They are about to become non-existent, like all the other once common TV's.

try cleaning the service switch. had same proble with my ctc68 i got at the early television museum auction. even though was was a new in box set,it had many issues. tuner was filthy,service switch was dirty and all the controls needed cleaned. these are truley rca s best solid state sets.very reliable and good,crisp picture.close to a zenith chromacolor in my opinion. i am using mine as a watcher while relaxing in my barber chair,(yes bryan,i did finish it!) good score and enjoy it!

I'll bet this set would really look good with one of those Sylvania black-face CRT's! I'm sure those are darn near impossible to find now.

The guy that owned this said that about ten years ago, his Dad was watching a ballgame on this TV when the picture suddenly went off. He got upset because he was missing his ballgame and quickly went and bought a new TV and rolled this one into the back room.

I will clean that service switch and the module contacts and see where that brings us. Fortunately, I do have a Sams on this set incase I have to go deeper.

BTW, who remembers the XL100 chassis that replaced this one? There was a CTC8? for the 19" sets and a CTC9? for the consoles. The chassis was flat and had several modules that plugged into the chassis. There was an MDR regulator module off to the side that RCA claimed was unrepairable. Those were still decent sets; but, not nearly as well built as the older XL100, IMHO.

CTC-92? I think that was the one I tinkered with last year. Finally gave up on it due to problems with that regulator module. I wasn't overly impressed by it. I don't think I ever had an RCA console from the mid-70s but I had some good table models. One was, I think, a 21"-kinda odd, whatever it was. I seem to recall it being from '75.

CTC-92? I think that was the one I tinkered with last year.

I'm drifting off topic for the moment here, but I had a CTC 101 set, the one with the comb filter. And the infamous bad flyback, the one with segmented high voltage windings with diodes between some of those windings. They first did 6 segments, and six diodes, but they tried to cheap out with just 3 diodes. The dynamic "AC" waveforms were too much for this design, and it would blow up after a while.

The yoke was interesting, in that the horizontal windings were "hot chassis" but the vertical was "cold chassis". The horizontal output circuits functioned as the set's switching power supply, with isolated outputs.

Aside from the bad flyback, this set had a great picture, I'd like to find another sometime (my old one got tossed when it died). If I had room, that is...

i sold a lot of those ctc101,s every single one had a flyback go bad. BUT rca did warranty them for 2 years and the replacements never failed with me. and those sets had a hell of a picture on them. steve

I've solved the video problem on the CTC78. There was no 240V going to the video output circuit due to an open R105 (180 ohm, 1 watt). R106 (18 Kohm, 1/2 watt) was also burned open. I'm sure this was due to excessive current being drawn through it when R105 opened.

Now, I've got to clean (if that's possible) those slide controls. They are hard to move and very touchy when they do move. I've never seen those slide controls on an RCA that actually worked right. Whoever came up with those needs a good butt kicking.

There is also an electrolytic going bad in the power supply. I can see a slight weave moving up the screen and there is some very slight pulling in on the sides that changes as the weave moves up the screen.

if that capacitor opens or shorts i have seen it take out the scr,s for the horizontal deflection more than once. those are one of the best sets rca ever made. i have my grandmothers she bought new in 1976 it is a larger cabinet and in the maple finish. the tube is weak and i have a new rca to install one of these days. it was only serviced once needing a new tripler.

if that capacitor opens or shorts i have seen it take out the scr,s for the horizontal deflection more than once. those are one of the best sets rca ever made. i have my grandmothers she bought new in 1976 it is a larger cabinet and in the maple finish. the tube is weak and i have a new rca to install one of these days. it was only serviced once needing a new tripler.

mine also has those darn slide controls

...

I had a CTC62 IIRC that had the SCR. Still have some of the modules if anyone needs them.

I really need to replace those slider controls. The contrast control is almost inoperative and they are all flaky and hard to move. I hope I can find something more substantial that will fit on the PC board.

I also noticed that the blue convergence is way off. Time to troubleshoot and/or adjust the convergence circuit.

RCAman, thanks for the warning concerning the cap taking out the SCR's. That will be my next order of business before I go any further. I noticed that when I turn the set off, I hear a faint "chirp-chirp-chirp-chirp" that sounds like it's coming from the horizontal circuit.

we have a LOT of 70s sets with thyristor line output stages here in Europe...

when restoring a set with a thyristor line output you want to resolder the entire line output stage carefully anc check the large mylar/poly capacitors for bulging and test them if possible, as failures in a thyristor line output stage can destroy the set and pose a serious fire hazard

I dug this set out and decided it was time to finish it. The 300uf,200V section of the main filter was open; so, I pulled a 330uf200V snap-in cap off of a newer TV chassis, unsoldered the old section, and wired in the good cap. I then touched up the CRT bias and drive controls, the convergence, and the vertical size control and it now has a decent picture. Those slide controls are still touchy; but, I'm leaving them alone. Unfortunately, I'll probably have to let this set go as I'm out of room. It will probably either be sold cheap, given to the SA, or given to a needy person who is not too stuck up to own a 33 year old TV without a remote. I'll post some pictures as soon as I get my hands on the camera.

How's the CRT holding up?

I wouldn't mind watching that set at all...Nice RCA's from this time are getting trashed at an alarming rate, which is unfortunate. The mid-70s to early-80s RCA's have been some of the best sets I've come across.

The CRT seems to be holding up OK. It actually has a better picture than a 1994 CTC177 Thomson/RCA that I just brought home.

Well, so much for pictures! I turned it on a while ago and now it appears that I've lost HV. When I turned it off before, I could hear a "click-click-click" coming from the horizontal sweep area. Now, I hear nothing. I have not opened it up to investigate yet and don't know if I'm going to. This thing is really in my way and I'm a little tired or replacing one thing after another.

As it happens, my favorite flea market vendor called a few minutes ago. He was at someone's house buying stuff and he said there was a working RCA XL100 solid state console there. He wasn't interested; but, thought I might be. I told him it really wasn't worth over $10. He told the lady and I could then hear her screaming in the background "TEN DOLLARS!!!! I'M NOT TAKING THAT!!!! THIS TV WORKS". Well, it may work; but, it's from the '70's and no one except a collector is going to give her ANYTHING for it! Hell, I can't sell 10 year old consoles that have cable ready tuners and remotes. Just another person that thinks because it's big and beautiful and cost $700 new; then, it should be worth a fortune!

I actually wound up at that estate sale where they turned down my $10 over the phone offer for the XL100. After going to the sale, I'm glad they did. The odor was enough to make one puke and it was one of those places where you felt like you needed a bath when you left. I looked at the set and it's actually newer than mine. It had the single knob varactor tuner with the power/volume and brightness knobs above the tuner knob. There were four other customer control knobs under the tuner knob. The cabinet was one of those long particleboard jobs with photofinish. I suspect the chassis was a CTC92, one of the last RCA modular chassis from around '78 or '79. The seller said she gave $125 for that set (used) back in the '90's. I told her that it was probably worth that back then; but, consoles are almost impossible to sell today, even if they are later model remote control models. I don't think she got it.

I still have not opened my XL100 to see what killed the HV.

I had a CTC-92 (I think that was the one) that did the click-click-click. Maybe that was the time I got a spare chassis from you? Apparently a little transformer went bad. The replacement did the same thing first time I powered up after installation. Now long gone to TV heaven. Must be something else that causes that thing to die? But your problem might be something different?

Mine does have audio, just no HV. Those CTC89/92 chassis use a different type of power supply where everything is derived from the flyback. My chassis still uses a regular power transformer; so, everything does not die if the horizontal circuit fails. I hope it's not something serious because I really don't want to sink much money into this set. The only reason I might be willing to go back in it is because I saw what kind of picture it can produce.

OK, I pulled the two ITR's in the horizontal circuit and checked them as best I could with a meter. Between the gate and cathode pins, I read 86 ohms both ways on one and 103 ohms both ways on the other. On the diode test setting, I read about .46 volts from gate to anode and when I reverse the leads and measure from cathode to anode. I used to have a homemade tester for these devices; but, don't know whatever happened to it. Do these sound like they could be bad based on my meter readings? It's been a long time since I've messed with one of these and I've almost forgotten what I knew about them. The part numbers are:

ITR101 is RCA # 141255 and crosses to an ECG310
ITR102 is RCA # 141256 and crosses to an ECG308

I think the NTE/ECG parts (which I'd rather not use anyway) are about $17 each. Unless I find something cheaper, I may let this set go. I really don't want to spend in excess of $30 on parts and still not have a working TV.