[TechAssist] Dead CTC 169-low 14v -detailed symptonsTECH

Thanks Dan,
    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
> > >
> >
> > Help make your TechAssist online repair tips
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> > with  unsubscribe  in the subject line.
>
>
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