Riddled TV Repair Forum

khnitz · Joined: 11 Feb 2009 Posts: 10 Location: Johnsburg, IL

I repaired a convergence issue on this Toshiba TN50X81 TV (March 2000)by replacing the convergence ICs. Original were STK392-110's - I used uprated STK392-150 parts for the repair (also used Sanyo parts). Convergence can be set find now.

After the repair, the set ran fine for several hours of testing, but I do notice that the Vertical convergence IC runs very hot. I checked and resoldered all connections on the convergence board, still the Vert Conv. IC runs hot. I also checked the low-ohm resistors to the convergence ICs...all of these measured fine and showed no signs of overheating. I did use fresh thermal grease when fastening down the new convergence ICs, too.

I replaced that hot-running convergence IC with another new one...the same thing is happening - it still runs very hot, compared to the other. I don't have a schematic for this TV set, yet, but the PCB is marked V (for vertical?) by the hot-running convergence IC - the H (horizontal?) IC is running much cooler. The TV shut-off again after 15minutes or so. gain, the vertical convergence IC is running very hot - you can only barely touch the heat sink. The horizontal convergence IC's heatsink runs warm, but not uncomfortably so.

Thanks for any help!

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