Sony Trinition has working colour for menu but not video input?

[majorbean]

Hi all, new here - just wanted to ask and see if anyone had any ideas for what to do with this Triniton kv-m1411u I got off someone the other day.

Essentially, the colour works fine on the green teletext (channel, volume, brightness etc) and a little blue menu i can get to come up with some combination of random buttons on the original remote I have too.

But for some reason any video input I give it, be it through SCART or the front composite, the picture is completely black and white Tried a few different game consoles, all the same.

I've opened it up and tried adjusting some of the little spinners to change alignments and that and even made the whole screen green and pink and such so it can clearly 'produce' colour, which leaves me very confused

I've had some people tell me it might be as simple as replacing the v-board as it handles the inputs or something? But there don't appear to any for sale online having used the part number from the service manual to look up stuff. But yeah would basically love to hear any ideas please. Thanks

[murphyv310]

From memory the subcarrier crystal and trimmer give trouble on these sets.
The graphics are derived totally differently than the colour from the decoder so they come from totally different paths.
Don't twiddle without the proper equipment you'll then be looking for two separate faults.

[HamishBoxer]

Welcome to the forum!This rings a bell although maybe not loud enough,it could be the Menu set wrong on input or there used to be a problem I think with some scart leads not being fully connected.Worth trying a different good quality one.

Other than that, I think you can get text ok even with a decoder fault.

[ben]

Originally Posted by majorbean

I've opened it up and tried adjusting some of the little spinners to change alignments and that and even made the whole screen green and pink and such so it can clearly 'produce' colour, which leaves me very confused

Cardinal sin!
The absolute worst thing if you don't know what you are doing is to go randomly twiddling things. This will likely now require the use of a scope and the service manual to reset, plus then you have the initial problem still to deal with.

Most these sonys needed a few pushes on the AV key to select between AV, AV (S-video,) , AV (RGB) etc.

One similar set I worked on for a family member shortly after digital switch over. It had never been used via SCART before. They tried a STB and got no picture. On opening it up I found one of the scart socket's pins was doubled over and was never soldered to the PCB from new!

In this case I would try the set with a UHF signal from a VCR to see if there is full colour.

[Kyle__B]

The telly has lost it's ability to process the chroma (colour) information inside the composite signal for sure.

Before you do anything else make sure that your SCART device is set to RGB mode, and that the cable is properly wired up to switch the TV over to RGB input. (Check pin 16 for voltage).

The reason I say that is that a lot of stuff isn't, especially cheaper cables. If the gizmo you're plugging in is known good RGB SCART and it's still got a black and white pciture on the telly then it points to bigger problems.

I'll bet any money that what you're plugging in is doing composite over a scart cable, and that if the telly gets fed proper RGB it'll spring into full colour.

No help if you want composite, but if you're plugging in a freeview box or a games console it's no loss.

[HamishBoxer]

That is it Ben,it possibly is as I suggested on wrong input,though Trevor has me thinking re the trimmer (30PF) which certainly caused trouble on another model.

I used to put in a fixed cap ,around 22PF I think,certainly did enough once.

[murphyv310]

The crystal and trimmer was a common issue across the board and was in many service bulletins. I remember the fault well, just model numbers that I'm rusty on. Did countless of these so called mods in Sony, in most cases it was the trimmer but you had to do both when working with the manufacturer.

[simpsons]

I'd go back to the "some people" who told you it was the v board and ask them just what did they mean or was it the same someone you bought it off? From the service manual, this is shown as the Teletext Board.

Did you note the position of "the spinners" known as pre-sets, you adjusted and, as you have the service manual, just what were they. Then the task will be to return them to their original position, then hopefully the task to get the set up and running will be easier.

Once working, provided the CRT is OK, the set will reward you with a very watchable picture.

Chris

[majorbean]

Thanks all for the responses!

I tried 3 different devices (PS1, PS2, XBOX, all known to work with other CRTs with the same original cables) through both the scart on the back and the little composite through the round ones on the front but yeah no luck no matter what

And while I had been fiddling with the twisty bits inside, I was checking the display the whole time and returning values to their original positions, so no harm done i think.

I also tried to do PS1 and PS2 in via RF but the tuning seems to be broken too as I can't pick up any signal at all, but something I did notice was that even walking around the signal would flicker and get darker and lighter, like something's barely making a connection inside as it is and just bumping brings it back and forth to life?

Seems like the general consensus is try some other cables, try to see if I'm just not using the right RGB mode and then try a VCR with UHF signal if possible and if still no luck it's the trimmer or crystal that needs to be replaced? I haven't had much luck with finding replacement parts online and it would be a shame to get rid of this poor guy but it looks like that's where it's headed

[Welsh Anorak]

Just to clarify for the OP, a picture on a colour TV is made up of red, green and blue. In the correct proportions this makes a black and white picture to which colour information is later added. The individual colours can be adjusted to get the picture correct in black and white.
Hopefully the 'spinners' can be returned to where they were originally and you'll again have a black and white picture. Then we can help. As detailed in the last few posts, there is a common fault, but we do need to know your level of experience as there are some nasty voltages in there - no offence intended, of course.

[Kyle__B]

Originally Posted by majorbean

I tried 3 different devices (PS1, PS2, XBOX, all known to work with other CRTs with the same original cables) through both the scart on the back and the little composite through the round ones on the front but yeah no luck no matter what

[snip]

Seems like the general consensus is try some other cables, try to see if I'm just not using the right RGB mode and then try a VCR with UHF signal if possible and if still no luck it's the trimmer or crystal that needs to be replaced? I haven't had much luck with finding replacement parts online and it would be a shame to get rid of this poor guy but it looks like that's where it's headed

One thing at a time, don't condense everything everyone has said into one.

Get yourself a pinout diagram of a Scart plug. Now take one of your games console cables, and open up the scart plug. You are looking for a wire going to pin 16. If that's not there, the telly won't know to use RGB.

I'll bet any money it isn't there. Cheap console scart cables almost always don't have it.

Actually, before that - these are real scart cables, and not just composite and audio plugs going into an adapter plug, right?

[simpsons]

The Playstation 1 & 2 RF aerial adapter should work causing the Sony to stop at UHF channel 36. You should then see the Sony logo etc.

The fact that it doesn't may not be related to the monochrome picture problem but as I haven't got the schematic in front of me I can't be sure but it suggests something is wrong.

Just make sure the RF adapter is working on another TV.

Chris

[Heatercathodeshort]

The I.F. unit is probably dry joint also. Multiple faults now the decoder presets have been upset. J.

[murphyv310]

Hi.
I'd go with John and say there is dry joints on the IF panel. Any issue there and they either wont lock onto the signal or there is no signal to lock onto anyway. Are you sure the modulator is producing a signal? If so the TV is multi faulted and not helped by indiscriminate twiddling.

[John123]

If it's really just the tuner/ IF section that's bad then probably best to totally bypass it and use as a dedicated RGB monitor.

You might be able to get away with using something like an old Panasonic DVD recorder to convert your Composite and S-Video inputs to RGB over SCART. Also doubles-up as a handy Freeview tuner/ recorder (if one of the later models), and I recall they have an analogue tuner as a fall-back.