Tatung C5GNEKC Problem

[Karetaker]

I have a Tatung C5GNEKC out of a Megatouch Force. The Merit number is EC9387-01(REV. E). The monitor was dead when I got it. The guy said it was intermittent. Sometimes it would come up sometimes it wouldn’t and then it just stopped coming up at all. I pulled it out to check the solders. All looked like they had been gone over not too long ago as they were still shiny. The flyback looked iffy so I went over that. I checked the neckboard solders and they were very dull. I went over them, and put it back together. Now it comes up every time but it still has an issue. The game is very dark and seems out of focus. As I adjust the bright or contrast up the screen gets white but the game graphics don’t get much brighter. Adjusting the focus on the flyback doesn’t do anything. Even adjusting the color adjustments on the neckboard do nothing. If I crank a color up it just stays the same. I pulled it back out and checked my solders. They all looked good with no blobs. I triple checked them with a magnifying glass and a meter. None are touching that shouldn’t be. When the guy dropped it off he didn’t say anything about this issue. He just said it wouldn’t come up at times until it finally wouldn’t come up at all.

Any ideas of what this could be?

[lilshawn]

these tubes are now quite old. the emissions from the colors guns are getting low.

(if you can still find one) take the tube to a television repair place and get it tested. a rejuvenation machine might restore the colors and the brightness.

be warned that the act of rejuvenation is VERY hard on the color guns of the tube. and as such it may do one of 4 things...in order of likeliness
1:) restore some brightness to the tube... for a few more years.
2:) do nothing.
3:) make the picture dimmer (worse)
4:) kill your tube so it will no longer display ANY picture.

you can try asking around and seeing if anyone on the board here lives around in your area and has a rejuvenator that can do it for you. i've even heard of some people lending them out (for the cost of shipping) or you can purchase one off of e-bay and attempt it yourself. (SEE WARNINGS ABOVE)

[Ken Layton]

http://home.comcast.net/~mtpacifico/_kenskorner/files/Tatung%20EC9387-01%20or%20C5GNEKC%20monitor%20repair%20guide.pdf

Zanen Electronics now sells a capkit for this model.

Kit # 664 Tatung C5GNE, EC9387 capkit, 41 capacitors, $7.95

http://home.comcast.net/~mtpacifico/_kenskorner/files/Zanen%20Capkit%20Catalog_2011.pdf

[lilshawn]

As I adjust the bright or contrast up the screen gets white but the game graphics don’t get much brighter

i just thought that there seemed to be an emissivity issue.

He just said it wouldn’t come up at times until it finally wouldn’t come up at all.

but this does sound like a cap issue... power supply not starting up properly.

so possibly both then?

[Ken Layton]

The cabinet has poor ventilation and all the electrolytic capacitors on the monitor bake dry. It's best to do a recap first then see how it performs.

[Karetaker]

I'll try a cap kit and see how it looks.

Thanks much!

[Karetaker]

I put a cap kit in with no joy. I didn't think that would cure it. Anything else?

[sarge]

I'd be willing to bet your tube is shot.  Common problem with the merit radion machines.  After you change the tube change R991 on the neckboard from a 3.3 ohm to a 6.2 ohm resistor to lower the heater voltage and prolong the life of your new tube.

[Karetaker]

Actually I believe the heater voltage is the problem. I'm only getting 1.3 volts out of it. Resistor tests good so I'm guessing the winding in the flyback. Which just seems so odd as I have never seen a heater winding go bad.