Riddled TV Repair Forum

[Jesse Mack]

Wendell,

You never said if the line was perfectly straight or not. If it is perfectly straight replacing the green gun is risky unless you find out what burned the crt in the first place. Confirming a burn is easy, Look directly into the crt while on. The burn will now appear to be a black line. If it is perfectly straight you need to check the yoke connectors for bad connections. Replacing the CRT before correcting the problem risks damaging the new CRT. I have not checked on the Samsung website to see if they have any issues like this yet.

The part number for the green crt is BP91-00778F

Jesse

[Google]

[Wendell1980]

yes the line is straight i turned off the blue and red guns, checked connections and the line still there so the culprit is the green gun.
the yokes seem to be fine those where tested.
i have heard of a few samsung sets with the same issue when the dcu board goes along with the stk ic's
and with blue and red guns off and cross hatch on the screen there is a black line.
why that happened i am not sure

[Jesse Mack]

I think you may have missunderstood about the reason for checking the yoke connectors. A black line on the screen (if it is exactly at 50 percent position) is an indication that there has been a vertical collapse on that CRT. It only takes about 30 seconds to severly damage a CRT on these sets if a vertical collapse occurs. I checked on the samsung website and there are no bullitons relating to this. However, it is not an uncommon occurance and is usually caused by the soldering of the pins that is directly on the circuit board that the yoke connector plugs into. If the line is not in the center of the screen you may be right about the cause. The bad connection senerio will only be valid if the line is in the exact center going across the screen.

Hope this helps

Jesse