Tatung 14428 Horizontal Size Help

[jthelman]

I just replaced Tatung 14428 chassis board that I purchased off eBay.  The picture is to large, I adjusted the pots for the vertical and horizontal size.  The horizontal pot is maxed out and is adjusted where I can't adjust it anymore and the picture is still to large.  I was told to adjust the horizontal coil on the chassis board but I don't see any horizontal coil.  What can I do to get the picture size smaller or where is this coil located?  Thanks for any help.

[cowboygames]

If the boards have the same model number, compare the flyback part numbers to be sure they match or cross to each other

[jthelman]

Not sure if the boards have the same model number, I don't see any model number.  The flyback original part number is #TFL 087-03-55A and the new chassis board flyback part #8101 227-31.

[cowboygames]

I no longer have my flyback cross referance guide. You might try google to see if the new one isn't for a larger tube than what you have

[jthelman]

I see there's two pots on the flyback, labeled focus and screen.  What does the screen pot do?

[cowboygames]

Screen is for base brightness setting. You set the user brightness control to it's lowest setting, adjust the control on the flyback so you can just see the picture, then turn up the user control to the desired brightness

[jthelman]

So is my next best option is to change the flyback to the original?

[cowboygames]

It's not a good idea to change anything without knowing the cause of the problem. Google "crt flyback crossreferance" and see if you can find out if those two numbers cross to each other before changing any parts around

[montech]

Hi jethelman and cowboy

Have you checked the poly cap C24 ? Not uncommon...it has a couple different values , .82 UF at 400V most common, but you replace with whatever it is. Also dont forget to replace  the infamous C19 (4.7@50V BIPOLAR.) I personally have never seen a flyback cause an oversize problem.

[jthelman]

Thanks for the help.  I bit the bullet and purchased a LCD.  I'll take a look and see what's installed on the Tatung and keep as a spare or sell it on eBay.  The horizontal size isn't terrible it's just a little larger than I would like.