Picture too large on Kortek ki-2-vo

[sebby59]

Greetings from France.   
And sorry for my bad english.

I have just find a old english arcade cabinet with a kortek  chassis.
it 's writed ki-2-vo on it.
Look like a clone of si-325 sharp image or kmf.

The picture on the monitor is pretty fine.

The only problem is that the picture is just too large for the screen.
1 inch of image is missing at the left and right of the monitor.

i have tried to turn the width button on the remote controler of the chassis, but the image don't stretch enough , and it pinch the center.

Before taking out the chassis and replacing all caps, i'm looking forward for some good advices.

Thank you very much if you know how to solve the problem ! 

[grantspain]

last time i worked on what i think your chassis is was around 15 years ago-there is a capacitor in the flyback shield that caused this issue

[southmonitor]

You have a bad Bipolar Electrolithic Cap in there. Should be easy to identify with  no polaridty markings and too big for it's value. You must replace it with Bipolar Cap designed for Horizontal Current Correction specifically. Don't use a regular audio bipolar cap since it will overheat. NTE, and Nichicon have good replacements.
http://products.nichicon.co.jp/en/pdf/XJA043/e-ha.pdf

[sebby59]

Hi ! 

Thank you southmonitor & grantspain. 

I have discharged the monitor today before seen your messages.
I have checked the chassis : no soldering problem, no caps damaged (visually).

Mine looks like :

schematics: http://www.vernimark.com/arcade/archive/monitor/mon_rc_si-319s.pdf

I will need to take out the chassis again to find this cap. 
So the cap must be "big" for his low value ?  Volt value  or the Farad value ? (or the 2 ?)

tks guys.

[grantspain]

i would look at q701,q702,c701,c702,c903
you will need to check the caps with a cap meter-looking is no good

[southmonitor]

Your problem is C701.

[southmonitor]

Il y a un problem pour moi avec the value of C701 (3.3UF/100V) in the schematic you posted though.
1- I have never seen a 100V Cap used for that application. They are normally 50V.
2- I have never seen it to be 3.3UF either. All I have seen are 4.7UF/50V, 5.6UF/50V and 10UF/50V.
For that reason I recomend you to check the real value of the cap that is in the circuit before ordering it, so you can have a perfect match.
Mouser Electronics or Digikey are good sources for those caps. I don't know for you there in France if they are good though. There are some repair tips in my website www.adrianelectronics.com. The bad cap in your monitor is probably swollen (inflated) at the top.

[sebby59]

Thank for this quick anwser southmonitor.

I will locate and change theses caps.
I think a good cap kit is needed as this lady is 19 years old. 

NTE and nichincon caps seems hard to find in France, they are only sold in large quantities for professionnal.

Anyway, i will try to find theses brands and follow your advices.

I'm not surprised that cap values in schematic look stranges.
My chassis is a ki-2-vo, but i can't find a schematic for it , and there is no manual in this arcade cab.

The si-319s is the only manual matching my stuff : same position, same trimers, same place for connection, tft...
But the manual said that the monitor is a 19'' sony , mine is a 25 '' samsung.

Maybe the si-325 is more accurate, but the PCB color is different and no si-325 label on mine... 



Thanks again for the help, i will get back as soon as we have changed some caps...