[TechAssist] Re: Sanyo DS31580--Looks like open filter
- From: Philip Bader <tjanphyl@xxxxxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Thu, 29 May 2003 11:37:49 -0400
I would replace the STR30130 without thinking.They do get noisey and are
inexpensive. Sounds like the two bands indicate a 120 Hz interference-
Thats the 60Hz line freq times-two (full-wave rectified).Also diodes in
the PS can have noisey junctions but work.Replace the bridge diodes and
STRxxx for starters.
Now the vertical is 60Hz so I don't think you need to go there.
Phil Bader
Tri-County Tv wrote:
>
> Hello fellow techs,
> Customer complains of white band across the
> picture, got it on the bench and seems to work fine except for 2 small lines
> moving up the screen, these lines are about as thin as 1 scan line and are
> separated by 2/3 of the screen. If we unplug the set from the isolation
> transformer and plug it into a non isolated outlet, the picture becomes very
> distorted with 2 large wide bands of distorted picture move up the screen and
> sound has a load hum, looks like open filter. I replaced main filter cap and
> few others that were marginal, replaced tuner isolation box, checked the ps
> diodes for leakage, maybe one of the ps diodes is leaking under load? What
> gets me is the fact that the isolation transformer makes it almost go away,
> so I am thinking some sort of grounding issue. It uses a STR30130 regulator
> and if you very the voltage to the set picture is rock steady. I do not have
> a schematic and sams does not cross, help, I am Stumped.
> Tom Berger
> Tri-County TV
> Robbinsville
> North Carolina 28771
> (tricountytv@xxxxxxxxxxxxx)
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--
Philip Bader
Jan Phyl TV Inc. (estab. 1976)
3420 Recker Hwy. Winter Haven, Fl. 33880
Fax (863) 299-8821
email: tjanphyl@xxxxxxxxxxxxxxx
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