Repairs: Looking for Schematics for CZ-614D Sharp monitor

[sananaman]

Hi, I'm about to start repairing my CZ-614D Sharp tri-sync monitor.
To get a better understanding how the monitor works I'm looking for the schematics.

Does anyone has this schematic or know where I could find it (in Japan)?

Alternatively schematics of CZ-611D, CZ-612D, CZ-613D, CZ-615D are also welcome.

[Cyothevile]

What is actually wrong with your monitor?

[sananaman]

Cyotheville:

Thanks for asking.

There are mainly 2 issues I want to get fixed:

• Sharpness after the monitor is turned on for 20 mins the image gets unsharp
  (I was able to fix it to change the setting on the flyback, but now it is a bit unsharp in the beginning and sharp after 10 mins.)
• The thing I need to get fixed is the geometry issue. From top to bottom the image goes slightly inwards. I see that a lot of these monitors have this issue.<br>
  (I'll post some pictures to show what I mean)

Pictures of the geometry issue (this is my monitor)




Others have this issue too

But I'm not the only one, I see many monitors on auction sites and google images that have the same issue.
To me that means this is a common issue and there shoud be a "cure" for it.





   


If someone has experience with repairing this monitor and knows what causes this issue and how to fix it.
This information would be very welcome.

Or if you know a very experienced CZ-6xxx monitor repair person send me a PM.
I really want to nail the issue, because I see so many monitors with exactly the same geometry issue. And if we know how to fix one we can probably fix them all.

[ImportantBet]

I fixed mine simply by changing the power supply and filter caps. Topped it off with magnetic strip tabs and yoke adjustments. Voila, perfect.

Check your B+ voltages. Fuzziness is caused by lower than expected voltages going into the flyback which under-drives HV output (especially at 31 kHz).

[Cyothevile]

I have the EXACT same issue as your first monitor with exact same geometry issue. I don't know of a fix for it

Adjusting all the potentiometers on the CRT chassis don't yield a fix for this. I think something in one of the specialized circuits for the CRT has failed. I don't think it's caps personally. Likely something else.

If any CRT wizards wish to comment we would welcome it.

[Cyothevile]

I have found a local CRT master in my area and it wasn't easy. He has been servicing CRTs in warranty since back in the 80s. He has agreed to take a look and repair my CRT and on the phone he knew the precise circuit that had a fault in the chassis or so it seemed on the phone. He will also repair my FM Towns UX20.

I will get this repaired by the master and then report back here what he does to fix it. Inshallah he can fix it.

[sananaman]

I have found a local CRT master in my area and it wasn't easy. He has been servicing CRTs in warranty since back in the 80s. He has agreed to take a look and repair my CRT and on the phone he knew the precise circuit that had a fault in the chassis or so it seemed on the phone. He will also repair my FM Towns UX20.

I will get this repaired by the master and then report back here what he does to fix it. Inshallah he can fix it.

Let us know how that repair went. Make some before and after photo's would be good to share that info.

[Cyothevile]

One really quick thing I'll point out that might help someone.

Composite video input didn't work at all with mine. I personally want everything working on my CRT not just RGB.

I ended up adding solder to the joint since the solder was cracked. That fixed that problem.

Again the circuit issue I'm not skilled enough to fix is what the gentlemen near me will hopefully take a look at and I will update here what was done.

[sananaman]

Thanks everybody and especially @TTTANK , I think that is a good start.

I think the repair will start a couple of weeks from now.

If anyone has any other suggestion, that would be welcome.