Wells D9200, 3 inches of black on the bottom that wont go away!

[grifter]

I have a D9200 monitor and I picked up two chassis's to go with it.

Both chassis have different issues so I picked one and replaced all the caps on the main board as well as the neck board.

Now the picture displays fine, perfect color, OSD works.

The only problem is that the image appears 3 inches up from the bottom and the top is corrupted (jittery).  The settings in the OSD will not drop the bottom of the image, they will only squish the bottom.
I can post a photo if it will help.

I have done the following
1) Tried 2 neck boards with the same result.
2) Tried 2 of the signal input boards (HD15 connector) with the same result.
3) Tried all different ribbon cables with the same result.
4) Replaced all the caps (except the ones on the Sync Decoder board and the Signal Input board.)
5) Tried 2 different remote boards (OSD controls) with the same results.


Has anyone seen this before?
Could this be related to the Vertical IC?
I didn't replace the caps on the sync decoder board, could this be the issue?

I do have a spare chassis to take parts off of, I just need to know what to try.

[grantspain]

does indeed sound like an issue in vertical deflection,have you tried factory mode adjustments?

[grifter]

Thanks for the reply.

I have tried the factory menus, same result as the normal menus.

Here is a picture of whats happening, you can see the botton is folding over

[grantspain]

hmm,you say you changed all the electrolitics in the vertical deflection circuit?

[grifter]

I replaced every cap on the main board (even the power supply side), but not the little verticle PCB thats located around the middle of the main board).  I have also replaced all the caps on the Neck Board.

I have not replaced the caps on the VGA input board.

I have lots of spare caps.  I could try replacing the last caps when I get home.

I will even try replacing any caps a second time that you guys can identify.  (I will try anything :-))

when I replace caps I color the tops of each with a sharpie so I know I didnt miss any.

[grantspain]

another possibility could a mismatch to yoke/tube

I have seen 2 version of d9200,one is for a pure flat crt and the other curved,i am not 100% sure but perhaps there are a few minor mods to be made when matching crt

you could contact wells gardner and get your crt number to chassis checked

[grifter]

So took both PCB's out today to compare side by side

they have a few different portions of the PCB populated

The old board has (confimed flat screen chassis)
AR101
c438
r197
r198
c456 (in different holes)
q416
r486

The new chassis is missing all of those components.  Maybe this is the difference between the flat screen chassis and the curved screen chassis.

Does anyone have a flat screen chassis that they can look at to tell me if those are populated?

[grifter]

So on second inspection these are the different parts
r497
r498
q416
q429
r486

So I moved them all over from chassis 1 to chassis 2. 
No difference.

So I moved over the vertical IC.  somehow this caused the screen to power on and click 2 times then power down.  I then put the old one back. and it continues to do the same thing.  Not sure what i broke here.....

Thinking about moving to the other chassis I have and attempting to fix it. (it clicks and has a high pitch sound that runs for a second then clicks again, high pitched sound, that repeats forever.)

[grantspain]

check you did not break a circuit trace on the vert def ic

[grifter]

Double and tripple checked for a short that I could have added.   I couldnt find one.

I decided to take a break and hit it again tomorrow.

Sometimes its best to walk away, decompress and come back to the problem. :-)

[grantspain]

nasty monitors mate,only ones i will not take on for repair