Help diagnosing Trinitron KV-32FV27

[Coolsuggies]

Hi, I don't know if there is a better place to post this question, but I'm looking for some guidance on troubleshooting an issue I have with this CRT TV I acquired. I have the service manual, a multimeter w/ oscilloscope. I was expecting to have a transistor be shorted with the red, but I don't think that's the issue. The most I can gather is that the FBT had odd voltages for what I would assume to be normal, and I just don't have any clue if that's part of the issue, the source of the issue, or just fodder to the problem. I've spent a good amount of time familiarizing myself with the board, the manual, and tutorials on how to use my multimeter, but I'm not an electronics guy by trade. What I find probably the most aggravating is most youtube videos that seem promising are not in English lol. I still try to follow along the best I can though. I'm posting a picture of what the TV is doing and what the FBT and HOT looks like. Thank you for reading.

 

[kellys_eye]

The voltages are meaningless without a schematic to compare them to.

Clearly the FB is working else you wouldn't have the raster. What do the internal controls do - is there a test pattern it can show? Is your input signal ok?

 

[Coolsuggies]

The voltages are meaningless without a schematic to compare them to.

Clearly the FB is working else you wouldn't have the raster. What do the internal controls do - is there a test pattern it can show? Is your input signal ok?

I have the service manual so I have the schematic. I'm just at a lost on what direction I should go. The voltages seem okay going into the jungle IC, but they don't seem to be correct coming out of it. Logically, I would assume that the jungle IC is culprit, but I'm not sure if another input on the IC is affecting it, and the issue is upstream so to speak. I don't really have a test pattern I can put on it. The menu is about the best 'thing' I can put on it right now. I have it so much apart that the inputs are disconnected currently. A couple questions in relation to your questions. What internal controls are we referring to exactly? If I raise the brightness on the FBT, it does get brighter and it does go dimmer than what it is if I want it to. The next question is what would be an input signal exactly, or are you referring to just hooking up something to it, for example a Nintendo or DVD player?

Thank you for help, and feel free to ELI5 because I know I have some gaps in knowledge. How can I help you help me? Again, thanks for your time.

 

[73's de Edd]

Sir Coolsuggies . . . . .

Consulting ye olde Sunny Service manual . . . . . on their page # 41.
You need to check out the "C " board . . . . . which provides RGB drive for the picture tube .
Your RED looks " extwe e e e e e e mely" excessive. . . . with retrace lines even . . . .
Check IC 1701 for ~ +2'ish volts inputs on its pins 1-2-3 and the more important reads will be on the outputs at pins 7-8-9.
Expecting trouble city being at pin 7 voltage reading . . . . as its being compared to 8 and 9.
Visually check all warm/hot running metal film resistors for thermally induced floating free solder ring joints that have opened up at the lead end to its solder blob at the PCB.
Confirm that E-cap C1794-----10 u @ 250V has not now declined down to .1 ufd with time onset attrition.
Confirm that E-cap C1751-----47 u @ 250V has not now declined down to 10 ufd with time onset attrition.
Also your 200VDC on the kine driver board , you only show as having 135 on it ? ? ?
That 200 VDC is created near the FBT at its pin 4 going to 200v rect diode D534 and then gets filtered by E-cap C541 and its 22ufd.
note that its - returns to grounding thru the 135V supply, so they only need to use a 100 VDC rating for it since it has 135VDC stacked between it and ground.
A decline in the efficacy of that E-cap C541 will cause 200V to be low at the kine driver board and its IC 1701 pin 6.

You say . . . .
If I raise the brightness on the FBT, it does get brighter and it does go dimmer than what it is if I want it to.
Two adjustment pots on FBT proper, they are Focus and G2 and . . . .
THAT AIN'T BRIGHTNESS . . . . . ! ! ! ! . . . . . rank neophyte / novices don't SCREW with that adjustment until after they have learned to walk.
Woe the person that has left G2 set too high . (ELI6mos)
Thaaaaaaaaaaaassit . . . . . .

73's de Edd . . . . .


Think about it . . . .
Life is being all about experienced perspective.
The sinking of the Titanic was a miracle to the lobsters in its ship's kitchen.

.

 

[Delta Prime]

Thank you for help, and feel free to ELI5 because I know I have some gaps in knowledge

What's ELI5?

 

[73's de Edd]

What's ELI5?
Explain (it to me) Like I'm (a) 5 (year old . . . or less ? . . . . . if leaving a mis adjusted G2 grids kine bias voltage supply! )

 

[Delta Prime]

Explain (it to me) Like I'm (a) 5 (year old . . . or less ? . . . . .

Thank you sir for the information.
You added the."or less" part didn't you?

 

[73's de Edd]

Ab-so-ROOT-ley!

 

[Coolsuggies]

Thank you so much for helping me.

I have confirmed that C1794 is still 10uf.
I have confirmed that C1751 is still 47uf.

I have tested D534 while it was on and got 205v on the cathode and 135v on the anode.

I have readings on the IC1701 as follows:
pin 1 is reading 2.99v and the schematic says it should be 1.8v
pin 2 is reading 2.95v and the schematic says it should be 1.9v
pin 3 is reading 1.5v and the schematic says it should be 2.0v
pin 6 is 204v. I can't figure out what it's suppose to be.
pin 7 is jumping between 167v and 178v. my meter says it's avg is 171v.
pin 8 is reading 99v
pin 9 is reading 99v

Seems you were correct with pin 7 being trouble town. Thanks again for your help.

 

[73's de Edd]

Sir Coolsuggies . . . . .

If my procedure to do I would swap that boards RED kine drive transistor with either of the two others.
To make it easy-peasy add fresh fluxed solder to CBE's until co-joining of all 3 occur, when you apply the side of your irons tip.
That transistor should almost fall out then. (Mark 1 transistor, so you don't accidentally reinstall them back in the same places.)
Take out both transistors then use a large sewing needle/of/=or>xstr lead diameter and insert and roll around until your CBE pads lead holes are cleaned of excess solder.
Reinsert transistors . . .swapped places . . .and then re solder and clear away all of that exxxxxxxxxxxxxxxcess solder that you used..
Now you Makee-Testee-Testee, and if the Red driver transistor was bad it will show up as faulting another color . . . B . .or . .G . . . .this testing time.

Thaaaaaaaaaaaassit . . . . . .

73's de Edd . . . . .

Works flawlessly . . . . .

"Excuse me miss, can I have the time?
I'd check my watch but I can't take my eyes off you."


.

 

[Coolsuggies]

Sir Coolsuggies . . . . .

If my procedure to do I would swap that boards RED kine drive transistor with either of the two others.
To make it easy-peasy add fresh fluxed solder to CBE's until co-joining of all 3 occur, when you apply the side of your irons tip.
That transistor should almost fall out then. (Mark 1 transistor, so you don't accidentally reinstall them back in the same places.)
Take out both transistors then use a large sewing needle/of/=or>xstr lead diameter and insert and roll around until your CBE pads lead holes are cleaned of excess solder.
Reinsert transistors . . .swapped places . . .and then re solder and clear away all of that exxxxxxxxxxxxxxxcess solder that you used..
Now you Makee-Testee-Testee, and if the Red driver transistor was bad it will show up as faulting another color . . . B . .or . .G . . . .this testing time.

Thaaaaaaaaaaaassit . . . . . .

73's de Edd . . . . .

Works flawlessly . . . . .

"Excuse me miss, can I have the time?
I'd check my watch but I can't take my eyes off you."


.

Sorry it took so long to get back to this forum. It took me awhile to deal with desoldering and reattaching components. The capacitors that you asked me to check where hard to reattach for a few reasons. Mostly because I'm an amateur. Once I got those reattached, I swapped the transistors to see if I would get another color. This took me quite awhile because they are surface mounted components. I am still getting all red though even when I switched the red and green transistor. This would indicate that I need to go farther backwards in the signal correct? Thank you for your help.

 

[73's de Edd]

Sir Coolsuggies . . . . . .

I swapped the transistors to see if I would get another color. This took me quite awhile because they are surface mounted components.

I was thinking back to ALL of the days of the past, with Sony's repeated use of three discrete plastic power / TO-220 plastic housings family of fast video transistors for the kine Red, Green and Blue driver transistors . . . being so, for the last "hunnert" or so, years.
In my re consulting of the units schematic . . . on page 41 . . . and your unit IS using the Sony AA-2U chassis . . . .isn't it ?
It is readily apparent that THOSE transistors are now being incorporated and built within the IC1701 . . .TDA6108.
(NOW I wonder where the heck ??? you found 3 OTHER . . . . . SM transistors, no less, that you thought were being them ? )

Now in consulting the schematic, we can see that the separate incoming RED,GREEN and BLUE video drives info for the 3 kine guns come into the C board as pins 1-2-3 of connector CN351.
Now with your screen presently being FLOODED by a RED raster, what you want to do is *** disconnect the wire coming into its pin #1 and then see if the RED screen dilemma then drops out . . . and then if you connect in a VCR or DVD player or even a digital TV tuner signal . . . to make a picture visible on the screen for its evaluation .
Expect that shown picture, will then be missing all of the red picture info, but the BLUE and GREEN info will be present to make a ghoulish picture.
If successfully in getting that picture type displayed on the TV screen . . .then . . . pull off pin 2 wire and swing aside and plug initial pin 1 (RED video) wire into the pin 2 connection. Hopefully, then expect a picture with red and blue info . . . but now no green. . . . then plug in the free wire into pin 1 and expect a BRIGHT green screen. If so, then as you have earlier deduced, the trouble is further on back, towards the jungle chip.

*** Take note of the wire colors on each pin # ! so as to know what wire color went to which pin ? later.

If being unfamiliar for the release of a plugged in wire from a JST type of connector . . . .which I think that they will be using.

HOWTODOITTOIT . . . . ( I use a #11 Exacto blades tip or a fine sewing needle ! )

Awaiting results . . .or further queries / difficulties.

73's de Edd . . . . .

What did Alexander the Great and Winnie the Pooh have in COMMON ?
( The same middle name.)

 

[Coolsuggies]

I am going to preform the CN351 stuff, but I wanted to just do a minor update on what I was talking about with the transistors.

 

[Coolsuggies]

Sir Coolsuggies . . . . . .

I swapped the transistors to see if I would get another color. This took me quite awhile because they are surface mounted components.

I was thinking back to ALL of the days of the past, with Sony's repeated use of three discrete plastic power / TO-220 plastic housings family of fast video transistors for the kine Red, Green and Blue driver transistors . . . being so, for the last "hunnert" or so, years.
In my re consulting of the units schematic . . . on page 41 . . . and your unit IS using the Sony AA-2U chassis . . . .isn't it ?
It is readily apparent that THOSE transistors are now being incorporated and built within the IC1701 . . .TDA6108.
(NOW I wonder where the heck ??? you found 3 OTHER . . . . . SM transistors, no less, that you thought were being them ? )

Now in consulting the schematic, we can see that the separate incoming RED,GREEN and BLUE video drives info for the 3 kine guns come into the C board as pins 1-2-3 of connector CN351.
Now with your screen presently being FLOODED by a RED raster, what you want to do is *** disconnect the wire coming into its pin #1 and then see if the RED screen dilemma then drops out . . . and then if you connect in a VCR or DVD player or even a digital TV tuner signal . . . to make a picture visible on the screen for its evaluation .
Expect that shown picture, will then be missing all of the red picture info, but the BLUE and GREEN info will be present to make a ghoulish picture.
If successfully in getting that picture type displayed on the TV screen . . .then . . . pull off pin 2 wire and swing aside and plug initial pin 1 (RED video) wire into the pin 2 connection. Hopefully, then expect a picture with red and blue info . . . but now no green. . . . then plug in the free wire into pin 1 and expect a BRIGHT green screen. If so, then as you have earlier deduced, the trouble is further on back, towards the jungle chip.

*** Take note of the wire colors on each pin # ! so as to know what wire color went to which pin ? later.

If being unfamiliar for the release of a plugged in wire from a JST type of connector . . . .which I think that they will be using.

HOWTODOITTOIT . . . . ( I use a #11 Exacto blades tip or a fine sewing needle ! )

Awaiting results . . .or further queries / difficulties.

73's de Edd . . . . .

What did Alexander the Great and Winnie the Pooh have in COMMON ?
( The same middle name.)

The A board side of this connection is CN351 and the C board side is CN1761. Just with that in mind, I took pin 1 out of the CN1761 connector and was still RED. Took pin 2 and put in pin one slot and left pin 1 cable out. Pin 2 is green according to my schematic. I was surprised to still see RED. I then disconnected the CN1761 cable altogether, and it was still RED as the initial picture shows.

Would this mean that I have a problem not backwards, but forwards? Is this a shorted red gun?

Thanks,

 

[73's de Edd]

Sir @Coolsuggies . . . . . .

Ahhhhhhhhhh yes, on the use of 3 minor transistors on the A board, since there must be need of extra gain between the A boards sourcing the RGB video and its sourcing out of its origin in the jungle board.
Would this mean that I have a problem not backwards, but forwards?
Indeed it is . . . and I am now wanting to believe that the contents of the IC1701 . . .TDA6108 is being hardly more than 3 video transistors and a luminance / I beam current controller feedback transistor.
Is this a shorted red gun?
I certainly hope not . . . . . as that is being an economically unfeasible . . . dead end

We do be getting closer now . . . . .
I'm placing a snippet of our new area interest just below.
Since I have no actual photo of the C board, nor can I visually inspect or move the unit around in my hands.
I have YELLOW dash line marked in three possible areas to work in, and opted for making a draw up in at the roomier central area
Behold . . .the YELLOW square markup . . . .
Since I cant see if leaded trios of 100 ohm and 1K ohm series inserted resistors were used . . . but am expecting SM at this last of the days of Sony manufacture of CRT based TVs.
I can't see working with either the terminals of the IC1701 or the CRT socket as being easy. Soooooooo . . . . I would opt for a cut out of 1/16 in of foil on both the RED and BLUE foil runs shown and then tin two end places on each cut out and use flying wire cross connects. See the YELLOW square inset.
Now, when you power up . . . . . just HOPE that the dominance of CRT color flooding has transitioned to being BLUE.
A last consideration is the top D1791 diode that is +200V hot on its left terminal and having developed any / some back leakage.
That, attributable to a prior time HV flashover within the red gun assembly.
That's about all . . . . . . that comes to mind.

C Board Snippet . . .



Thaaaaaaaaassit . . . . . .

73's de Edd . . . . .

You should never brush your teeth with your left hand . . . . . . ¿ WHY ? . . . . . because, a tooth brush works much, much better.
.

 

[Coolsuggies]

I attached two pictures but they are the same thing just different views. I swapped R and B and I still get RED screen

 

[73's de Edd]

Sir @Coolsuggies . . . . . .

I swapped R and B and I still get RED screen

Au contraire . . . . . . . don't think so . . . instead, I believe that you have now shorted the R and G video drives together !

On my mark up I had two options of its placement, one . . . up at the cramped top where I made a YELLOW dash mark across, or the bottom area that I ended up using, where there was being plenty of drawing area.
On your mark up . . . . I can see your initial definitive marking in of starting cross over wires into the R and B foil busses, but at their ends, with their arrow tips placed at the center of resistors . . . . . was interpreted by me as the tacking on of wire ends to already tinned solder blobs at SM resistors . . . but, being unsure of WHICH end, but there would only be a 1K res difference between the two options.
Now look down to my markup where I used an old style drafting crossover loop ( signifying no connection) to confirm no connection for a crossing over of wires/foils.
ALSO take note of the center point gaps I cut across the foils . . . . . stopping prior connectivity.
Therefore there is being a definite swapping of B and R drives.
Unless you gapped the foil paths up above , you just shorted R and B drives together.
As the condition is, the RED is flooding the screen so HARD, that we can't even see if any kines BLUE or GREEN info is even being present.

LOGICAL NEXT STEP . . . . .
Pull your wires and get conditions back to initial conditions

Then just open the foil path of the RED video, somewhere between the RED kine socket pin and R1763 and then power up to see if RED flooding is still present, if not, then finally, you might expect to see some BLUE and GREEN luminance.
(This test is a shortcut to evaluate of there being some Red K to filament leakage or an actual short in that kine's Red gun. )

Thaaaaaaasssit.

Absolute Factoid . . .
Women spend more time wondering what men are thinking . . . . . than men spend thinking.

.

 

[73's de Edd]

prior Errata . . . my post
I believe that you have now shorted the R and G video drives together !
I believe that you have now shorted the R and BLUE video drives together !
Absolute Factoid . . .
Women spend more time wondering what men are thinking about them . . . . . than men totally spend . . . . . . . thinking!

 

[Delta Prime]

Absolute Factoid . . .
Women spend more time wondering what men are thinking about them . . . . . than men totally spend . . . . . . . thinking!

Geez...try something original; show us your dirty and mean sense of humor like @Bluejets . I may learn to like you yet!

 

[Coolsuggies]

prior Errata . . . my post
I believe that you have now shorted the R and G video drives together !
I believe that you have now shorted the R and BLUE video drives together !
Absolute Factoid . . .
Women spend more time wondering what men are thinking about them . . . . . than men totally spend . . . . . . . thinking!

I believe I understood the idea what we were trying: switch red for blue and blue for red. Maybe I didn't do it correctly, but now I have disconnected red and blue entirely and still get only red. Here's a picture of my board and I hope you aren't scarred for life by how bad this looks. I figured, regardless of what I didn't do correctly from the last suggestion, this would at least show that I have successfully disconnected red and blue entirely.