SONY TV Chassis RX-2 no otutput at +B

EDAboard.com Forum Index -> Service Manuals, Requests, Repair Tips -> SONY TV Chassis RX-2 no otutput at +B

Author

Message

tendi

Joined: 26 Jan 2006
Posts: 68
Location: zimbabwe

04 Apr 2008 8:50 sony rx2 chassis

Does anyone know the resistance reading of the main primary winding of the smps(srt) across pins 6 and 9? I am getting 13Ω and there is no output at +B. I think the resistance is too high? I thought it should be ≤ 1Ω. See image...

tendi...

Google
AdSense
Google Adsense

04 Apr 2008 8:50 Ads

banjo

Joined: 24 Dec 2005
Posts: 644
Helped: 118

16 Apr 2008 13:20 SONY TV Chassis RX-2

I do not think the resistance is the problem. 13 ohms sounds fine for a primary winding with lots of turns. Either you have lost VBB to pin6 or the transistor on pin9 is not conducting.
My guess is that either the switcher cannot startup or has detected a fault and shut down. This is assuming that VBB is present and the transistor on pin9 is OK.