CRT TV repair, color issues, trinitron kv-21r1d

[komrad2236]

Hey everyone, hope you all doing good.

I was gifted this sony trinitron TV from dead relative and I am hoping to repair it.

I have a website where I documented everything from the issue to diagram,what I tried so far, what I measured etc.

https://hmrkv21r1d.weebly.com/

Please if you have time, check it out, any kind of help or guidance would mean a lot.
I will be trying everything unless it turns out that tube is worn out/broken, in that case its either parts bin or just going to leave it as a fond memory.

Thanks

 

[kellys_eye]

It's an issue with the green channel - whether the signal is missing or the green 'gun' in the tube has gone is to be determined.

 

[komrad2236]

What should I do or test next ?

 

[kellys_eye]

Disconnect the colour channels and connect either the red or the blue signal to the green gun and see if you get a picture. If not then the gun is dud. If so then the green signal needs to be checked (oscilloscope needed).

 

[73's de Edd]

Sir komrad2236 . . . . .

Individual C board builds also use some hot running metal film resistors on feeding their kine drive power transistors , so check to see if one has not developed a cold solder ring joint and popped open from its PCB connection.

Your efforts were being concentrated on the " C' board / panel . . .with no definitive answer being provided by your tasks.
So, now move back to the cabling found between the main chassis module CN081 connector and its other ends CNC71 at the C module and see if either end is being " connector friendly " in the respect of inserting a straight needle / scribe point / mini jewelers screwdriver end . . . . .into one of its pin 4 or 5 or 6 of its wire connections .

OBSERVE VEWY-VEWEY CLOSELY . . . as it should be possible for that action, to then release a locking pin (s) , which will then let that wire connector release and thus be able to slide / pull out of its plastic surround housing.

ONE CONNECTOR EXAMPLE . . . . .



Here there are two . . . .but sometimes only one spring out tab . . . . on the bottom side of this connector is used.
If a spring out tab is pushed in at the arrow point (s), it should let the connector and its wire, be able be pulled out of its housing.
If not being sprung inward in that process, then it can be inserted in another connector position, and then have it snap out and lock into that new position.

Then if you will pull the GREEN drive wire connector and preferably the RED drive wire connector , swap their positions.
Then hopefully you will THEN have some GREEN video information and expected loss of all of the RED video information . . . . . on your next view of the test pattern foray.
Thus, you need to look back to IC001, backwards, to troubleshoot, as being your potential problem area.
Furthermore, back at the input of IC001, you have the option of inputting a SCARP signal into J401 from a companion inputting device to use its RGB information as another viable input test source .

73's de Edd . . . . .


BUT . . . . I'm being selective . . as I work my way down aisles, I am holding a large
cereal box covering it up, until just before I come upon any PRIME candidates.

.

 

[Martaine2005]

Adding to the above posts, check all the solder joints. Sony TVs were renown for cold/dry or cracked solder joints.

Martin

 

[komrad2236]

Thanks guys and specially 73's de Edd, your detailed explanation made exchanging pins easy.
As I am total beginner, I need detailed instructions.

Original photo used

First here is how it is without pins being replaced


So heres what I did,
On CNC71 part of connector,
I first replaced Blue and Green and got this



Then I put the blue back as it was, and replaced Green and Red and got this

 

[komrad2236]

Adding to the above posts, check all the solder joints. Sony TVs were renown for cold/dry or cracked solder joints.

Martin

Thanks I will do that.
_______________
I was thinking guys,
I just sent green color from main board trough blue and red line on C board, and in both cases green was not good.
But I also sent blue and red from main board trough the green line on C board and they showed up, shouldn't that mean that the gun is good ?

Or am I wrong ?

 

[73's de Edd]

Sir komrad2236 . . . . .

You say . . .
I just sent green color from main board trough blue and red line on C board, and in both cases green was not good.
But I also sent blue and red from main board trough the green line on C board and they showed up, shouldn't that mean that the (GREEN) gun is good ?

Lets initially do a fast forward to just see if you can get some GREEN display on that picture tube before involving any greater in depth analysis time.

Look at both the 'C' board schematic and its physical parts layout and find RED driver circuitry related L704 and BLUE driver circuitry related L702 and do a power off measurement of their resistances, expecting both to be of the same resistance , then locate GREEN driver circuitry related L7043 , and hope that it reads a p p p p p p p reciably higher resistance or, better yet, it being completely open circuit.

I AM NOW STOPPING . . . . . TO AWAIT YOUR FINDINGS . . .thusly. . . . . . . . .

73's de Edd . . . . .


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