a few questions about arcade monitor

[ranma]

Ok, I finally got an arcade cabinet, it was a hard work but I could get one, not very nice, generic but it's ok.
Now, the most important part that I was looking for was the monitor. I was a little disapointed since it wasn't in a very good shape but after some work I got a soso pic on the screen.
The monitor is from my country I think (Argentina) so I don't think anyone of you ever heard of it, the brand is "clarex". Fortunatelly the guy that sold it to me gave me the schematics.
These are the problems I'm geting:
1. The image it's too wide, and I can't stretch it to fit the screen. I can strech it but in the maximum it's still to big.
2. The image it's not linear. If I see one of those grids of white lines that some games show when they start the right squares are smaller than the left ones.
3. The image it's moving a lot.

Now, I think that problem 3 it's tipical of bad caps, right?, so changing the caps should help?, should I change only the electrolitic or all of them?, what about the big electrolitic one?
Problems 1 and 2 I have no idea, does anyone have any idea?, the adjustment of horizontal size it's done by a variable inductor (moving the ferrite nucleus)
Thank you.

[Ken Layton]

Problems 2 and 3 should be repaired with a capacitor kit. Just the electrolytic capacitors are the bad ones and the very largest one (the main filter capacitor) usually does not get replaced as it does not fail much.

[ranma]

Well, I must admit I was a little sceptical about this. But it actually worked great, it solved problems 2, 3, 4 and 5  
well, I didn't list problems 4 and 5 before because I wanted to solve the other ones first, but they were solved with this.
They were:
4. The neck of the tube did an anoying buzzing (and I was a little concerned about it)
5. There was some noise all arround the screen (now that I think about it's logical that it would be related to the other problems)

Now I have another question, once in a while the image grows a little and then goes back to normal, but it not constantly happening. Could it be old/dirty pots?, what do you think?
Thank you.

[Ken Layton]

The noise and the picture shrinking/enlarging could be the "yoke" on the neck of the picture developing a high voltage electrical 'leak' (not good at all). Maybe even the flyback transformer getting ready to explode/burst/crack.

[JasonF]

Now I have another question, once in a while the image grows a little and then goes back to normal, but it not constantly happening. Could it be old/dirty pots?, what do you think?

I have seen a dirty pot do this before when the pot is used to control the B+ voltage (i.e., on a G07).  

[fredster]

The flyback is bad.

[dc740]

Hello. I'm also from Argentina and I'm desperately trying to get the schematics for the Clarex argentinean monitor.

I don't have many posts, so I'm a newbie member, so I can't send "ranma" an email. I know this post is 10 years old, but it's the only reference I've found about this monitor in the net. Can someone with more privileges tan me send the OP an email to request his help?

Thanks, I hope you guy understand why I revived a 10 years old post. There aren't many chances to get the original schematics other than contacting ranma, who has a printed copy.

[dc740]

Ranma! I can't send private messages because I'm a new user. Thanks for replying so quick. It's disappointing to hear you couldn't fix it. My only problem right now is that the monitor losses the vertical synchronization, and the tube is out of focus. I found someone who can fix it, but the professional demanded the schematics to do it. He doesn't want to screw things up.


Thank you!!