View Full Version : KV-1222RS Trinitron Vertical


targeteye
08-19-2017, 09:52 AM
Hello All,
I acquired this trinitron recently. It should clean up pretty good and I have the remote to go with it but I am weary of getting into a really involved project. Generally speaking are these TVs simple to service?

Turned on with nothing connected i would expect to see a full screen of static and certainly the audio works. As I change chanels you can see the singly horizontal sweep change brightness so something seems to be working :).

I'm hoping this is a common problem for these sets and you folks can give me a pointer where to check first ... an i'm hoping its an easy fix.

This TV is a perfect match for my Atari 800XL computer and i'd like to get it going again.

Thanks
Steve

Popester
08-19-2017, 01:57 PM
You'll need a schematic of this one. No vertical sweep. You could do visual check on PCB for bad solder connections. But a schematic will be a must on a Sony set. Good luck.

zeno
08-19-2017, 02:27 PM
Should be able to fix this with a good meter, schematic & a little
knowledge. Nothing comes to mind as far as common vert
problems on this set. Looks like the CRT is strong but dont
run it like that. Turn down the G-2 until you barely see a line.

73 Zeno:smoke:
LFOD !

targeteye
08-19-2017, 03:10 PM
ok... thanks guess I'll need to see about getting a service manual.

The remote dosesn't seem to work and I can't seem to figure out how to program the channels without it. :)

Steve

zeno
08-20-2017, 09:46 AM
Sony made a few sets that needed an OEM remote to add
& delete channels. They were all subbed to a big combo remote that
dealer net was abt $65 !! The manual will have an RM number
for the origional. Look on e-bay then.

73 Zeno:smoke:
LFOD !

Tom9589
08-20-2017, 10:49 AM
You may need to take your remote apart and clean the contacts. Some mysterious grunge gets on the PC board and the switches no longer work reliably. Rubbing alcohol and Q-tips work just fine. I've resurrected many an OEM remote with balky keys that way. Also be sure to clean off the back side of the polymer keyboard as well with the alcohol.

Marco-nix
08-21-2017, 07:43 AM
Here is a video od a remote control ( How to ) you'll have a good idea . On Youtube


https://youtu.be/yWpMcXWlhBE

Zenith26kc20
08-21-2017, 10:09 AM
No vertical is usually the vertical IC and some capacitors connected to it. The caps cause the IC to run hot and fail. A sure sign caps are bad, once the IC is replaced is a foldover at the top of the screen.
I remember that I had to add to the heat sink to keep the IC alive. Apparently towards the end of that IC's popularity, seconds were being sold. I had the same trouble with Zenith power supply IC's when the sets with all the shorted CRTs came along. The seconds always ran HOT!

targeteye
08-22-2017, 04:04 PM
Thanks all..

I'll give the remote a cleaning and see if it it helps.

Looks like the vertical IC is UPC1378H . Pretty cheap on Ebay. I'll order a couple to have on hand to swap it out. Sounds simpe enough.

if it fixes it then i'll shut it back off quickly and go for a recap.

Steve

Findm-Keepm
08-22-2017, 05:47 PM
No vertical is usually the vertical IC and some capacitors connected to it. The caps cause the IC to run hot and fail. A sure sign caps are bad, once the IC is replaced is a foldover at the top of the screen.
I remember that I had to add to the heat sink to keep the IC alive. Apparently towards the end of that IC's popularity, seconds were being sold. I had the same trouble with Zenith power supply IC's when the sets with all the shorted CRTs came along. The seconds always ran HOT!

With those Sonys, the chip is rarely bad - it's usually 1) the 22uf/50V cap off the yoke return - it's open, and ESR will be >10 ohms or so 2) Solder connections at the chip itself 3) Bad 24V or 28V source feeding the chip 4) the 10uF boost-up cap, also in the vertical area.

With lightning strike sets, the chip will usually short, taking out the 24 or 28V source - replacing the chip fixes that, but you wouldn't have a picture with the chip shorted. Two different versions - the UPC1378 and the UPC1488 - you have the earlier, and the caps are usually the culprit.

OP, have you checked the solder on the chip, and the presence of the 24-28V source feeding the chip?

MadMan
08-26-2017, 01:54 AM
You might be able to find the service manual online for free, do some googling.

My later model Trinitron gave me hell with cracked solder joints. I'll bet if you completely remove the PCBs and go over them with a magnifying glass, you'll spot plenty of problems. Warm up that soldering iron!

targeteye
01-06-2018, 05:04 PM
With those Sonys, the chip is rarely bad - it's usually 1) the 22uf/50V cap off the yoke return - it's open, and ESR will be >10 ohms or so 2) Solder connections at the chip itself 3) Bad 24V or 28V source feeding the chip 4) the 10uF boost-up cap, also in the vertical area.

With lightning strike sets, the chip will usually short, taking out the 24 or 28V source - replacing the chip fixes that, but you wouldn't have a picture with the chip shorted. Two different versions - the UPC1378 and the UPC1488 - you have the earlier, and the caps are usually the culprit.

OP, have you checked the solder on the chip, and the presence of the 24-28V source feeding the chip?

Ok so i finally had time to try and do something with this TV. After getting the dust out of it ... the I checked and the IC is not getting any voltage to it. Should be 24V on pin 6 but it reads zero. TP96 also reads zero. I'm trying to wrap my head around this schematic and figure out how the 24Volts is generated but not having much success.

Here is a link to the schematic, Its to big to upload here.

https://drive.google.com/file/d/1bTdS_eVo4gmK4utapidF393x2r1Gs29Z/view?usp=sharing

Steve

targeteye
01-06-2018, 05:47 PM
Here is what I have been able to deduce / theorize what is happening.

1. The flyback transformer has secondary windings on it that are also used to supply +15 and +25 volt dc source via rectifier diodes D514 and D508.
2. Checking the +15 volt supply confirms it is working.
3. Checking the +25 volt supply indicates it is NOT working.
4. D514 test good.
5. Resistance from pin 11 to pin 6 of the FBT indicates very low resistance as expected.
6. Resistance from pin 11 to pin 8 of the FBT indicates about 11 Meg and indicates an open winding on the FBT and this is what supplies the 24 volt supply.

Conclusion... I doubt a FBT could be found and I have a 1983 curb prop.

Let me know what you think :).

Steve

MadMan
01-06-2018, 08:19 PM
Did you go over the boards with a fine-tooth magnifying glass?

While it's on try some percussive maintenance. You know, the caveman method. What we mechanics call the wiggle test. Just hit the thing and move stuff around, and see if anything changes. I'd still put my money on a cracked solder joint.

targeteye
01-06-2018, 08:23 PM
No but you but I did where the flyback transformer is. The coil is definately open.

More steps taken.

7. After giving some thought i figured I could always rig an external source of 24v if I have the parts laying around to do it.
8. Hooked up my bench power supply to the 24 volt TP and gave it a try.
9. I now have virtical deflection and its drawing about 100 ma (less that the spec sheet call for on that chip.
10. Now to get a universal remote to program .. all it need to be able to do is set the channel and I can set it to channel 3 and test with an vcr or something.

More to come.

Steve

targeteye
01-06-2018, 09:50 PM
ok so understand this is the only "vintage" tv I have ever messed with ... I had to go find an old DVD player and fix it it first (the mechanisms were sticking from non use). Got it working and scrounged up an RF modulator I remember I stowed away "just in case I ever needed one ?>

Then I had to scrounge for a non-widescreen DVD!.. sheese.. could only find the Wild Thornberry's.

Well, now to figure out if I want to build a quick 24vdc supply or look for another junker tv to rob a FBT out of.

Also, I clearly have no idea how to take a picture of a TV :)

Steve

jr_tech
01-07-2018, 12:20 AM
Perhaps figure out the turns per volt ratio of the transformer and add a new winding for the 24 volt supply.

jr

MadMan
01-07-2018, 01:19 AM
Neat. Just throw a small power supply in the case somewhere lol

zeno
01-07-2018, 08:45 AM
Never had a pulse winding open, most unusual. At the time
Sonys with ADD/DEL on hand unit had no universal sub.
You may be able to random access any channel but I just
dont remember.

73 Zeno:smoke:
LFOD !

Marco-nix
01-07-2018, 09:31 AM
... I had to go find an old DVD player and fix it it first (the mechanisms were sticking from non use). Got it working and scrounged up an RF modulator I remember I stowed away "just in case I ever needed one ? ..........


Steve

What i don't understand , I have an old RCA 1979 B&W and i can't put a DVD to my tv !! is there some tricks or ??

targeteye
01-07-2018, 10:46 AM
Perhaps figure out the turns per volt ratio of the transformer and add a new winding for the 24 volt supply.

jr

Good suggestion but i think it would be easier to just install another supply considering the mechanical construction of the FBT.

Steve

targeteye
01-07-2018, 11:25 AM
Never had a pulse winding open, most unusual. At the time
Sonys with ADD/DEL on hand unit had no universal sub.
You may be able to random access any channel but I just
dont remember.

73 Zeno:smoke:
LFOD !

The ADD/DEL is on the TV, you just need the remote to punch in the channel, then push ADD on the TV.

Steve

targeteye
01-07-2018, 11:43 AM
What i don't understand , I have an old RCA 1979 B&W and i can't put a DVD to my tv !! is there some tricks or ??

You need one of 2 things.

1. A DVD player with modulated RF output. I suspect not many of these were made... if any.
2. An external modulator such as the one in the picture. It takes composite video, and L/R Audio and modulates the information on to usually Channel 3 or 4.

The modulators were produced by the gazillions when things like DVDs and VCRs stopped installing internal modulators and folks still had old tv,s that excepted only RF input (or had a limited number of inputs). Just search Ebay for Television RF modulator. You can now get them for very little money.

Now .. like I said i'm brand new to the "old tv" scene. Is there something about a B&W set where this will not work? I don't think so but perhaps someone more knowledgeable will chime in. I vaugely remember something about copyright protection messing with the signal to prevent duplication but I think that was on VCRs.

Steve

Marco-nix
01-07-2018, 12:48 PM
You need one of 2 things.

1. A DVD player with modulated RF output. I suspect not many of these were made... if any.
2. An external modulator such as the one in the picture. It takes composite video, and L/R Audio and modulates the information on to usually Channel 3 or 4.

The modulators were produced by the gazillions when things like DVDs and VCRs stopped installing internal modulators and folks still had old tv,s that excepted only RF input (or had a limited number of inputs). Just search Ebay for Television RF modulator. You can now get them for very little money.

Steve


Don't worry, my B&W tv's working fine.. i have the RF output but not the device in the picture. So i should buy one..i just can watch my tv with a VCR(VHS)...

Electronic M
01-07-2018, 03:34 PM
You need one of 2 things.

1. A DVD player with modulated RF output. I suspect not many of these were made... if any.
2. An external modulator such as the one in the picture. It takes composite video, and L/R Audio and modulates the information on to usually Channel 3 or 4.

The modulators were produced by the gazillions when things like DVDs and VCRs stopped installing internal modulators and folks still had old tv,s that excepted only RF input (or had a limited number of inputs). Just search Ebay for Television RF modulator. You can now get them for very little money.

Now .. like I said i'm brand new to the "old tv" scene. Is there something about a B&W set where this will not work? I don't think so but perhaps someone more knowledgeable will chime in. I vaugely remember something about copyright protection messing with the signal to prevent duplication but I think that was on VCRs.

Steve

Macrovision copy protection existed on both VHS and DVD. Only some recordings had it, some players and external boxes eliminated it. Older TVs (pre-1980) sometimes were bothered by it.

targeteye
01-07-2018, 04:45 PM
The project comes to an end.

Well folks its been interesting and a learning experience.. :).

Installed an external regulator. Worked like a champ!

Then a test lead falls into a circuit and poof.. Fried circuitry .. bummer.

oh well. I'm going to put this in the attic and look for a working version of the same model and save this one for parts.

Steve