Another TV I recently added to my collection this summer. It is a Heathkit GR-2000 solid state color TV. I picked this tv up for free from a home that was being cleaned out. From what research I have done on this tv. This tv was sold as a kit for people to build starting in 1973 until at least 1976. My particular tv was already built by the previous owner in the early 1980s according to his daughter. The tv parts are all dated at various months in 1976 so it was likely that this tv kit was not built until a few years after purchase.

It appears to be a low hour set. All caps tested good using my Capacitor wizard. I recapped some anyways since I had extra low voltage ones and that went well. The issue with this tv appears minor and related to loose cold solder joints where the coaxial and antenna hookups go on the back of the tv. It may possibly also need some adjustments to the convergence.

TV is very advanced for its age. All transistorized including the HV stuff. TV has LOTS of IC chips, digital channel display and a clock board to show the time! TV is in great shape aside from a few scuffs on the handmade wooden cabinet which has metal roller caster wheels on it.

I knew of Heathkit but never knew they offered TV kits. I am very impressed by the design and the ease of which I can service the boards if need be.

CRT appears to be fine when turned on. Will post more updates as I work on it.

https://imgur.com/a/JLTZlPO

A follow up to my first post, I am able to get a picture on the tv from my VCR via RF out channel 4 but the convergence appears to be off fore some reason, along with the horizontal having some issues at the top of the screen. Vertical hold though is ok. Here are some photos showing the issue. Not sure if the CRT directly needs adjustment or if it is an issue with the tuning circuit/board due to drifting values of carbon comp resistors.

I turned on dot mode for the last few pictures to show the convergence issue more clearly.

https://imgur.com/a/k8WogaA

That looks a lot like a Zenith with HealthKit additions. The first heath kits were rca’s with a crosshatch generator added. I built a HealthKit black and white set back around 1965.

I just saw your Imgur posts regarding your Heathkit GR-2000. However, I wonder why the picture which, in at least one upload, seems to have a bend in it, similar to the bend caused by defective filter caps in older TVs which causes 60Hz AC to get into the sweep system. Is there any hum in the sound as well?

Aside from the CRT, I don't think this TV has any other tubes, so the problem, if there is one, would almost have to be caused by defective filter caps in the power supply. The GR-2000 is 100 percent solid state, so heater-cathode shorts in tubes cannot cause hum anywhere in the set.

The only other thing I can think of, however, which could cause a bend in the picture would be the auto degaussing coil, which may not be shutting off completely when the TV is powered on. Normally, the degaussing coils will operate for a few seconds at most; the coils will have been shut off by the time the TV picture appears on the screen.

Not a Zenith design. Zenith bought Heath in 1979. There were some later Heathkits based on Zenith chassis, I believe, but they involved much less construction and soldering and were more snap-together if I recall correctly.

The fact that the dot pattern is straight shows that this is not a power supply hum problem. It is probably a reaction to the VCR signal horizontal jump at the head switching time. Either something has failed in the horizontal AFC or more likely this set has an earlier design of the horizontal AFC filter section that predated VCRs. Another possibility is that there is a switch setting for a shorter AFC time constant, although I don't recall if there was one on the Heathkit I built in 1975.

Play a DVD or digital converter box into the set instead of the VCR and verify that the wave goes away.

The other thing that indicates this is a VCR signal vs/ AFC problem is that the offset is worst at the top and decays towards the bottom. A power supply hum would be constant amplitude and slowly drift vertically.

Not a Zenith design. Zenith bought Heath in 1979. There were some later Heathkits based on Zenith chassis, I believe, but they involved much less construction and soldering and were more snap-together if I recall correctly.

The fact that the dot pattern is straight shows that this is not a power supply hum problem. It is probably a reaction to the VCR signal horizontal jump at the head switching time. Either something has failed in the horizontal AFC or more likely this set has an earlier design of the horizontal AFC filter section that predated VCRs. Another possibility is that there is a switch setting for a shorter AFC time constant, although I don't recall if there was one on the Heathkit I built in 1975.

Play a DVD or digital converter box into the set instead of the VCR and verify that the wave goes away.

Good call! I did what you suggested and tried a digital to analog OTA convertor box along with an antenna, and the horizontal issue went away. The issue that is left now is the convergence being way off especially in the top part of the screen. Also the sound is fine!

https://imgur.com/a/IrdSRJU

I've got a 2000 and it does that too. Its caused by the motorola chip that doesn't like the non RS170 sync coming from a vcr.
There was a motorola publication out to address the issue. A number of manufacturers used that chip.
Now, I've converted my 2000 to composite video input. Easy modification!

This is one of the RCA clones with SCR Hoz sweep.
Later they did sell Zenith with the System 3 chassis.

Convergence is easy. TIP turn color off & brite & contrast about half way.
In other words dont drive it hard. If its just the top give the top
controls a little bump first to see if one has a bad spot. Also
watch for cold PC on the board, it gets hot there !

73 Zeno:smoke:
LFOD !

This is one of the RCA clones with SCR Hoz sweep.
...
73 Zeno:smoke:
LFOD !

Yes, the horizontal is RCA.

Some other things, like the pre-aligned and potted IF filter are unique to Heath. This is a precursor to later TVS (including Zenith) that used SWIFs (Surface Wave IF).

Yes it does have SCR output but the oscillator chip is a MC1391.
Attached is the video input mod for the 2000. I used a Maxim MAX405 video op amp which might be a little hard to find these days.
The video goes in at the emitter of Q326. (Q326 is removed.)
I'm sure Linear Technologies makes a similar chip.

This is one of the RCA clones with SCR Hoz sweep.
Later they did sell Zenith with the System 3 chassis.

Convergence is easy. TIP turn color off & brite & contrast about half way.
In other words dont drive it hard. If its just the top give the top
controls a little bump first to see if one has a bad spot. Also
watch for cold PC on the board, it gets hot there !

73 Zeno:smoke:
LFOD !

It appears that the adjustable inductors on the convergence board just had their plastic hex screws disintegrate over the years as they fell apart when I was trying to adjust the blue left and right. As far as the pot convergence knobs go they all work fine except for the white knob which seems to not react at all. Not sure what to do know, The red and green are almost perfect now but the blue is still way off especially in the left and right parts which is what those adjustable inductors control.

this is completely unrelated to the thread topic, but for some odd reason :D

the name "Lain" scares the crap out of me~ :tears:


does the term " Accela " mean anything to you? :O

this is completely unrelated to the thread topic, but for some odd reason :D

the name "Lain" scares the crap out of me~ :tears:


does the term " Accela " mean anything to you? :O

What a coincidence :3 As a matter of fact it does. I see I am not the only person who has watched Serial Experiments Lain. It is my favorite anime. hehe

What a coincidence :3 As a matter of fact it does. I see I am not the only person who has watched Serial Experiments Lain. It is my favorite anime. hehe

I saw it WAY back when it first came out on 98 subtitled ( fansubed )

and I laughed at people when it came out "pro" dub in the states years later and they would say "THEY RIPPED OFF THE MATRIX!" and I would tell them NO, the Matrix ripped of LAIN! :P

Perhaps I have found another anime to watch...

Preface:

I will admit that I did a major goof up awhile back when I was removing the boards for recapping. I had accidently while being in a hurry and not paying close attention accidently put one of the boards on the wrong way (right orientation but shifter to the right by one pin margin to where one pin was not connected and the others shift over by one). I realized this mistake when turning on the tv and not getting vertical deflection and smelled a horrid burning smell emanating from the tv. I quickly turned it off and fixed the mismatched board and all seemed to be well after that....for awhile. Unghh well I am not making that mistake ever again.

I used my CRT tester on this tv as well. No shorts in the CRT were found and WOW are the color guns strong. This tv was certainly not used much. Sadly, I ran into another issue with this tv recently when I tried to turn it on and adjust purity and convergence for it.

First off I am not longer getting vertical deflection just a horizontal line. But it gets worse, I turn the tv off quickly and after inspecting the tv I notice a burnt/shorted carbon comp resistor (I tested it to verify it was bad) The resistor was on the horizontal output board just above the high voltage cage which houses the flyback. So I replace the resistor with a high quality metal oxide resistor of appropriate wattage and value.

I turn the tv on again and this time I get nothing at all, no filament being lighted up even. Just the hum coming from what I think is the high voltage area. This leads me to believe the issue is regarding the voltage somehow being low or off due to a bad winding in the flyback or perhaps the Double or tripler went bad.

I don't have a high voltage probe yet to test the voltage output so verifying voltage output will have to wait. I did try resetting the circuit breaker switch which I am unsure of if it actually tripped. This did not fix the issue.

I am at a loss at this point as to what may have went wrong exactly.

No further knowledge as to what caused the CRT to no longer light up. I am assuming yoke burnt up and TV is a goner. I should have just left it alone and gave it to someone.

Well I found out at least part of the issue and should have suspect this sooner. It looks like the power supply board on this tv has a thermistor and posistor for controlling the automatic degaussing. The thermistor appears on visually but....the posistor will a picture is worth a thousand words.

The posistor was found dangling loosely between the two leads and fell off as I touched it. Somehow this failed but I do know thermistor tend to fail often on old tvs so I would assume the same is often true for posistor as they are related components.

https://imgur.com/a/PKW0Y8F

I ordered and obtained the original heathkit manuals and books for the tv including the partlist. The partlist is of not much help though it appears what actually failed was the thermistor but other than a heathkit part number, the part list provides no ohm values whatsoever and the schematic I already have had not given any other info either. How do I find out what the ohm value was supposed to be for this thermistor? Any place to cross reference heathkit part numbers?

Preface:

I will admit that I did a major goof up awhile back when I was removing the boards for recapping. I had accidently while being in a hurry and not paying close attention accidently put one of the boards on the wrong way (right orientation but shifter to the right by one pin margin to where one pin was not connected and the others shift over by one). I realized this mistake when turning on the tv and not getting vertical deflection and smelled a horrid burning smell emanating from the tv. I quickly turned it off and fixed the mismatched board and all seemed to be well after that....for awhile. Unghh well I am not making that mistake ever again.

I used my CRT tester on this tv as well. No shorts in the CRT were found and WOW are the color guns strong. This tv was certainly not used much. Sadly, I ran into another issue with this tv recently when I tried to turn it on and adjust purity and convergence for it.

First off I am not longer getting vertical deflection just a horizontal line. But it gets worse, I turn the tv off quickly and after inspecting the tv I notice a burnt/shorted carbon comp resistor (I tested it to verify it was bad) The resistor was on the horizontal output board just above the high voltage cage which houses the flyback. So I replace the resistor with a high quality metal oxide resistor of appropriate wattage and value.

I turn the tv on again and this time I get nothing at all, no filament being lighted up even. Just the hum coming from what I think is the high voltage area. This leads me to believe the issue is regarding the voltage somehow being low or off due to a bad winding in the flyback or perhaps the Double or tripler went bad.

I don't have a high voltage probe yet to test the voltage output so verifying voltage output will have to wait. I did try resetting the circuit breaker switch which I am unsure of if it actually tripped. This did not fix the issue.

I am at a loss at this point as to what may have went wrong exactly.

I don't know this model, but some things I wonder if occurred:
I'm have the impresion that the inverted board can be shorted with the inversion since (is the vertical output one?), when you changed the burnt resistor, the TV cannot work anymore. I wonder if this board don't have making shutdown or blowing fuses on TV (or messing with driver/oscillators/controllers).
Certain TV models derive vertical power from flyback, also, to be in mind.

There are several possibilities with the Heathkit tv...I just hope it is nothing major from when I put that one board on off by one pin, it was right side up though. Shorting was likely happening to some extent when that happened, hopefully no damage was done to the yoke. Once I get a New old stock thermistor on and recap all old electrolytics I will be able to rule at least bad capacitors and the thermistor out. Without the thermistor however, it is certain that this tv will not turn on until then sadly.