Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: southmonitor on July 29, 2010, 07:13:44 pm

Title: Kortek KT-2938F
Post by: southmonitor on July 29, 2010, 07:13:44 pm

Hi:
Does anyone knows wher I can find the Schematic or Service Manual for the KORTEK KT-2938F. I have one with a blown HOT (J6820) and the IRF840A. I replaced them and now I have HV; but only a Vertical line in the center of the screen (No Horizontal Deflection). Most components are good when tested without power. I need the schematic to chase the problem.
Thanks.

Title: Re: Kortek KT-2938F
Post by: qrz on July 30, 2010, 09:28:12 pm

 
multi sync monitors usually have seperate HV and Hsweep circuits.
the Hsweep will likely have a mosfet xistor ( irf840a) driving an xformer/deflection output xisitor.
voltage will vary per sweep frequency. check components here as you would any H output stage.
always inspect for loose connections etc...

 can u post a fairly high res pic of both sides of the pcb ?

Title: Re: Kortek KT-2938F
Post by: southmonitor on August 03, 2010, 10:11:50 pm

Hi:
Thanks for your reply. I found the Schematic with Casino Tech. Sorry I don't have a high res camera that can take good close ups of the board.

Title: Re: Kortek KT-2938F
Post by: southmonitor on August 03, 2010, 10:23:04 pm

There was originally no HV up until I replaced the HOT and the IRF840A. Evenwhen both the HV and the H-sweep circuits are independent, because those transistors were shorted, they were imposing too much load on the PS and it was not starting the monitor with no HV either.

Title: Re: Kortek KT-2938F
Post by: qrz on August 04, 2010, 09:17:20 pm

just seeing the print is an advantage  !

have a link , or can post/email it ?