Sony Trinitron KV34HS510 geometry issues

[MRX37]

Yesterday I had the fortune to obtain one of the last CRT HDTV's ever made, A Sony Trinitron KV34HS510 made in 2004. DA-4 chassis.

I'm lucky with this set as it's in excellent cosmetic shape, comes with the original remote, and I have a bit of history with this set. I repaired it some years ago, replaced a bad IC in it because it wasn't powering on.

Now that I've wrestled the beast into its new home, not an easy feat seeing as it weighs 167 pounds, I'm working on tweaking the image the best I can. Color and grayscale are excellent, no changes needed there. However the geometry is off.

The image is bowed at the top and bottom, making the TV look like it's frowning at me.

I found the service manual, entered the service menu and made a few adjustments. Most notably there's a VPIN adjustment which helped the top, but did nothing for the bottom, and did nothing for the on screen menus. I reset the VPIN to default before I took the pic I have attached below.

Far as I can recall the geometry's always been a bit off on this set, or at least it was when I fixed the IC in it years ago. How can I correct it? The image is beautiful otherwise and I really want to make use of this TV.

[Arcanine]

Try this.


# Using the remote control:
# Turn the TV off.
# Press {DISPLAY} {5} {VOL+} {POWER ON} buttons.
or
Press {DISPLAY} {5} {POWER ON} buttons.
# The Service Menu will be displayed.
# Use numbers {1} and {4} to select the item to adjust.
# Use numbers {3} and {6} to adjust the value of the data.
# Press {MUTE} then {ENTER} to save new settings.
# The words "WRITE" in red will show up in the upper right corner if saved.
# Turn the TV off to exit the service menu.
Back to top

All sony sets have this. it lets you change everything about the set.

[MRX37]

Arcanine, I should have been more clear. I have the service manual, which told me how to access the service menu.

The VPIN adjustment in the service menu helped the top but does nothing for the bottom. I cannot find an adjustment that helps the bottom, and even after adjusting the top, the on screen display and menu is still bowed.

[zeno]

These were always good IIRC pin wise. I would check the pin
diodes in the H Out then follow it back & watch out for 'lytics.
But usually a bad pin diode or cap across it gives a much worse
barrel or pin shape & adjustment does little or nothing.

On some sets there is a control that moves things up & down
for pin adj. You would center the distortion then use pin adj to
even it up. Probably has a strange name.
I got a few training manuals from that era. I will see if anything
useful when I get time & let you know.

73 Zeno

[MRX37]

Ok I'll wait and see what you have. I'd rather solve this in the service menu if possible because the last time I worked on this thing was... well it was memorable wrestling that heavy sonofabitch out of its cabinet.

Could there be a marginal cap? Getting the top correct required adjusting VPIN almost to the max.

[Findm-Keepm]

V-PIN and V-CEN work hand in hand - get the bow even at the top and bottom / centered at the edge with V-CEN (this is with V-PIN at midrange, we used 32 as mid range IIRC - most adj's are 0-64 or 0-16 for adjustment IIRC) and then adjust V-PIN for the best Pincushion - it will not be 100% but very close. If it is really whacked, look for bad caps on the W board, or D board if you have no W board. Pincushion ckts could be on either.
Also, make sure you are in the correct register for the video mode - hard to tell from your screen shot, so I can't directly advise on which register to adjust first.
We had to use a computer hooked up to the set to adjust the second (VGA) mode for proper V-PIN in that mode. OTA worked before the digital transistion for the 1080 and 480 mode. Now, I guess you could use a computer for all the modes - high/low res and mid res.

[MRX37]

Originally Posted by Findm-Keepm

V-PIN and V-CEN work hand in hand

That did it! VCEN was the key!

Funny the service guide does not mention VCEN in its section on correcting geometry. Why?

Now I have the picture near perfect. It's still a little off, mainly in the lower left corner but I think I can live with it. I've never had a CRT TV with perfect geometry.

One minor worry is I had to adjust VCEN and VPIN to just about the extreme range.

[Findm-Keepm]

Originally Posted by MRX37

That did it! VCEN was the key!

Funny the service guide does not mention VCEN in its section on correcting geometry. Why?

My copy of the manual has it in paragraph/section 2.2 - V-PIN adjust, and mentions the V-CEN quite clearly. Do you have the full manual, 286 or so pages?

2-2. V-PIN AND V-CEN ADJUSTMENT
Preparation:
• Input a cross hatch pattern signal.
• Set Video Mode to: Standard (Reset)
• For all 4X3 CRT, VPIN data has separate register for full and Vcompress.
Adjust both modes if needed.
1. Adjust service mode CXA2170D-1 05 V-CEN so that the top pin and
bottom pin are symmetrical from top to bottom.
2. Adjust service mode CXA2170D-1 06 V-PIN so that the top pin and
bottom pin are symmetrical from top to bottom.
3. Horizontal lines should be straight from left to right. Check landing for
side effect.

The default values for V-CEN and V-PIN are about 15 for each, per the manual.

[MRX37]

Doh... Yeah there it is. I was looking in section 2.9.

Made some more small adjustments. It's still not perfect, but it's now in the realm of "Won't really notice it during a movie" so I think that's good enough.

Also some of the geometry values in the service menu were not what the service manual listed as default which makes me think somebody else was in here futzing with it before me.