Panasonic Quintrix F TC-21P50R help diagnosing the problem

[Sultanpepper]

Hello everyone, I've had this for more than 20 years so it's quite sentimental. It was stored for a couple of years in storage and then we moved to another location and as you can see in the videos this was the surprise. I'm still trying to gather information and watch alot of videos to be as ready as
I can before opening the back as I am aware there are alot of hazardous areas back inside. BTW I've got the service manual.

The Problem :

TV is flickering and colours are not aligned (convergence issue ? ), not all input channels (composite/RCA) act the same and the Component Input acts differently I think. The video will speak a thousand words I'm sure.

Videos from each input channel

1- AV1 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=6lfxpImx8yE
2- AV2 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=LHWeE9C8_nE
3- AV3 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=x0LMW_M6MHc
4- DVD (Component cable from a OG Xbox ):
https://www.youtube.com/watch?v=FgS4MNPdFKM


TV Model : Panasonic Quintrix F TC-21P50R
Service Manual : LINK

I would really appreciate if any one would help me in sharing his/her thoughts on what are problems I'm having and where and how to fix them that would be really appreciated.

Background : I'm always looking to learn new things and in my free time I like to buy and fix broken stuff which is quite therapeutic. I have no former knowledge in fixing CRT's but I always research before I get my hands dirty, of course I would greatly appreciate if someone guide me to a basics/FAQ for troubleshooting CRT's that would be quite beneficial and fun I imagine.

Best regards
SP

[old_tv_nut]

First thing is to differentiate source problems from TV problems.
Can you try inputting the DVD / OG Xbox into AV1, AV2, and AV3 to see if it works there? Likewise, can you connect the PS1 to input #4 and see if it still fails?

[Sultanpepper]

Originally Posted by old_tv_nut

First thing is to differentiate source problems from TV problems.
Can you try inputting the DVD / OG Xbox into AV1, AV2, and AV3 to see if it works there? Likewise, can you connect the PS1 to input #4 and see if it still fails?

Hello sir, Thank you for the suggestion. I have recorded OG Xbox into AV1, AV2 and AV3 ; they are acting nearly the same as the PS1 or PS2 .

Videos below for OG Xbox :

1- AV1 (Composite cable from a OG Xbox ):
https://www.youtube.com/watch?v=2LLz_DR7gtM
2- AV2 (Composite cable from a OG Xbox ):
https://www.youtube.com/watch?v=5HdMMLGjWfA
3- AV3 (Composite cable from a OG Xbox ):
https://www.youtube.com/watch?v=OxAS3mfC-DU
4- DVD (Component cable from a OG Xbox ):
https://www.youtube.com/watch?v=FgS4MNPdFKM

For the PS1 Unfortunately I do not have a component cable for it for input #4 , but I have composite and component cables for the OG Xbox .

Please let me know if you need any more tests or data that I can do ,I really appreciate the help.

BR

[zeno]

First off thank you for the good prep you did. Some tell you almost nothing.
This looks challenging especially without lots of equipment.
1) if you have an old game or VCR try that through the RF.
2) if you have no inputs hooked up is the OSD stable ?
3) try tapping ( with authority ) the set & see if that effects it.
4) if the manual has a block diagram ( not the schematic ) post that.
It shows the flow from stage to stage & is a BIG help on high end sets.
5) DO NOT go into the service menus at this time !!!
6) when you pull the back take a chassis picture. That helps us remember
a set.

Let us know what you find.

73 Zeno
LFOD !

[Sultanpepper]

Originally Posted by zeno

First off thank you for the good prep you did. Some tell you almost nothing.
This looks challenging especially without lots of equipment.
1) if you have an old game or VCR try that through the RF.
2) if you have no inputs hooked up is the OSD stable ?
3) try tapping ( with authority ) the set & see if that effects it.
4) if the manual has a block diagram ( not the schematic ) post that.
It shows the flow from stage to stage & is a BIG help on high end sets.
5) DO NOT go into the service menus at this time !!!
6) when you pull the back take a chassis picture. That helps us remember
a set.

Let us know what you find.

73 Zeno
LFOD !

Hello sir, Thank you for the suggestions.
1) Unfortunately no , I do not have anything that outputs RF anymore, they got thrown out a long time ago .
2) The OSD looks to be nearly perfect , a bit fuzzy if someone looks too close for any problems.
3) Tried tapping/hitting actually at the back it went from current to worse on one of the channels (AV3) .
4) I've scrolled up through the service manual and I could not see a block diagram .
5) Ok, Gotcha loud and clear.
6) I'll try to take some pictures tomorrow right after work, my apologies for the delay here.

I'd like to add highlight on the Component input with an OG Xbox in the picture below



I apologise I was not very helpful this post , Please let me know if you need any more information or specific demonstrations I need to capture (video/images) or measurements with a multimeter in specific areas , Kindly note that I currently have no idea how the CRT TV is divided into (Blocks) and what are the voltage levels I need to check and test if needed.


BR

[Sultanpepper]

Originally Posted by zeno

First off thank you for the good prep you did. Some tell you almost nothing.
This looks challenging especially without lots of equipment.
1) if you have an old game or VCR try that through the RF.
2) if you have no inputs hooked up is the OSD stable ?
3) try tapping ( with authority ) the set & see if that effects it.
4) if the manual has a block diagram ( not the schematic ) post that.
It shows the flow from stage to stage & is a BIG help on high end sets.
5) DO NOT go into the service menus at this time !!!
6) when you pull the back take a chassis picture. That helps us remember
a set.

Let us know what you find.

73 Zeno
LFOD !

Hello , my apologies for the late response. I've uploaded a couple of photos for the Chassis PCB as per your request.







Also I've opened up the TV and took out the Chassis ( Main PCB ) and measured voltage rails and they are very low. Secondary all are very low and the main offline regulator IC I've measured it's Vin Supply and it's supposed to be 16V but its 12-13V and it's fluctuating. Please let me know if you have any ideas I'm at a road block

Note: Since I have the service manual, I've used the schematics as a guide but I spent an entire day pulling out suspected components and measuring them ( caps and diodes ) but nothing was out of the ordinary.... please help .....

BR

[zeno]

When you measure voltages you need to use the cold ground.
The tuner shield is a sure bet. Almost all the voltages come off a
flyback winding ( s ). HV looks normal.
Since you got reaction hitting it look at the jack pak connectors for cold joints.
Also check the whole chassis for heat areas for cold joints. Then
re seat all connectors. You can also tap around now & see if it comes & goes.
After that you will need to trace the signal through the video. I would use
composite for that.
Knowing where the OSD comes in will tell you anything after that is OK.
See if you can figure that out.
BTW a LONG shot but run the model & chassis numbers & see if anyone posted a TRAINING manual.

73 Zeno
LFOD !

[Sultanpepper]

Originally Posted by zeno

First off thank you for the good prep you did. Some tell you almost nothing.
This looks challenging especially without lots of equipment.
1) if you have an old game or VCR try that through the RF.
2) if you have no inputs hooked up is the OSD stable ?
3) try tapping ( with authority ) the set & see if that effects it.
4) if the manual has a block diagram ( not the schematic ) post that.
It shows the flow from stage to stage & is a BIG help on high end sets.
5) DO NOT go into the service menus at this time !!!
6) when you pull the back take a chassis picture. That helps us remember
a set.

Let us know what you find.

73 Zeno
LFOD !

First I'd like to apologise for parking this repair attempt due to work. Second I've borrowed an old VCR and connected it to the RF input and the screen is showing same distorted picture .... any clue what that might mean when all inputs give bad screen ?

For the voltages ( main ones ) 5V , 12V , 9V ,1.2V coming at the secondary sides after the voltage regulators they are working fine , turns out I needed to hookup the screen or something for the voltages to work properly; meaning the chassis will not give correct voltages on its own .

I changed the vertical IC just for kicks but it did nothing . Also I tried recapping around the voltage regulators and the vertical IC .

BR