[TechAssist] Fw: Dead CTC 169- FIXED low 14v -detailed symptonsTECh




> all:
>     Main problems were CR4101,
> (thanks Anthony Marini) and U1001. CR4101 caused regulator to switch
without
> pulsing and 14 volt line was steady at 13 volts.U1001 was dead, no
> horizontal driving pulses with external 9 volts applied.Replaced these two
> above components and set works fine.I suspect surge from lightning as the
> two main failures don/t seem related.. Also replaced
> the usual small parts and U4101,Q4101,C4108,CR4122,CR4118, and Q4401.
> Obviously all were not needed, but I left them in for insurance./ al
>
> Al's TV
> 224 Rt. 46
> Mine Hill, NJ. 07803
> 973-361-5796
> alleathe@xxxxxxxxxxxxx
> Subject: Fw: Dead CTC 169-low 14v -detailed symptonsTECH
>
>
> >
> > Subject: Fw: Dead CTC 169-low 14v -detailed symptonsTECH
> >
> >
> > >
> > > Subject: Dead CTC 169-low 14v -detailed symptonsTECH
> > >
> > >
> > > ,
> > > >     Working late last night,so I screwed up on symptoms! The 160
volts
> > is
> > > on
> > > > collector of the reg (Q4101)the h.out (Q4401)is 120 volts.The reg
> pulses
> > > > from zero to about 250 volts (peak to peak).The 120 volts is
steady(no
> > > > load?)the 14volts is down to 8 volts.The 5 volt standby is ok.I
> suspect
> > a
> > > > load on the 14 volt line.
> > > >    The horizontal never fires up even if I power pin # 25 on Ul001
> > > > with external 9 volts.There is no driving pulse at #23 (U1001) with
> the
> > 9
> > > > volts on #26.The shutdown pin remains at zero.
> > > >     I am going to replace Q4101 later, even though it isn't shorted
> and
> > > > obviously is driven.
> > > >     When keyed "on" with remote
> > > > the "on" pin on the micro jumps for a split second and remains low.
> > > >     I suspect lightning damage as this came in after a stirm period.
> > > > appreciate any help. I will post when fixed. al
> > > >
> > > > Al's TV
> > > > 224 Rt. 46
> > > > Mine Hill, NJ. 07803
> > > > 973-361-5796
> > > > alleathe@xxxxxxxxxxxxx
> > > > ----- Original Message -----
> > > > From: "Daniel" <danielstarca@xxxxxxxx>
> > > > To: <techassist@xxxxxxxxxxxxx>
> > > > Sent: Thursday, August 30, 2001 12:27 AM
> > > > Subject: [TechAssist] Re: Fw: CTC169 14volts down to 8volts-dead set
> > > >
> > > >
> > > > >
> > > > > Dear Al:
> > > > >  That Horizontal Output Transistor Collector voltage
> > > > > is way too high.I think you are observing Regulator
> > > > > action(shut down intiated by Micro).
> > > > >  Suspect components around That I.C. you
> > > > > changed,especially the two diodes cr4401,cr4402.
> > > > > -Daniel
> > > > >
> > > > > --- AL LEATHERMAN <alleathe@xxxxxxxxxxxxx> wrote:
> > > > > >
> > > > > >
> > > > > > Subject: CTC169 14volts down to 8volts-dead set
> > > > > >
> > > > > >
> > > > > > > All: changed ic driving chopper-chopper pulses at
> > > > > > about 200 volts peak to
> > > > > > > peak,160 volts on hor.out.
> > > > > > > no pulse from jungle ic to hor driver, even with 9
> > > > > > volts applied to jungle
> > > > > > > ic. Micro produces on pulse briefly but stays
> > > > > > low.Appreciate help. also
> > > > > > > rerplaced famous diode
> > > > > > > in 14 volt/5 volt stand by circuit. al
> > > > > > >
> > > > > > > Al's TV
> > > > > > > 224 Rt. 46
> > > > > > > Mine Hill, NJ. 07803
> > > > > > > 973-361-5796
> > > > > > > alleathe@xxxxxxxxxxxxx
> > > > > > >
> > > > > >
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>

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