[TechAssist] Re: FIXED: Re: Panasonic PV-M1368 RelayDriver Problem 2ND Request
- From: MDileo0000@xxxxxxx
- To: techassist@xxxxxxxxxxxxx
- Date: Sat, 27 Nov 2004 09:14:28 EST
Found a steering diode, D506, near the vertical output IC had high
resistance leakage (15meg). Seems like this is part of a safe-to-run
proving/latching
circuit for the relay and sweep circuits. Looks like the ABL is tied into it,
also.
Dominic DiLeo
Atlantic TV
Freeport, Maine
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In a message dated 11/24/04 12:54:29 PM Eastern Standard Time,
woodman1@xxxxxxxx writes:
<< Dominic,
Can't help you with the print.. But we had one just like, Base of
relay transistor would not toggle on/off...tracing base back to micro we
found a small smd shorted to ground..
Bob,
Bobs TV Worcester, ma
woodman1@xxxxxxxx
Main 508-853-1482
Fax 508-853-1480
----- Original Message -----
From: <MDileo0000@xxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Wednesday, November 24, 2004 12:33 PM
Subject: [TechAssist] Re: Panasonic PV-M1368 RelayDriver Problem 2ND Request
> This thing is a buster. Need a scan of the relay control and peripheral
> circuitry Q801,Q505, 506, 507. Something is holding the base of Q801 down.
> Bootlegging from a 12 volt source will let it turn on and all appears
normal. Please
> help.
> Dominic DiLeo
> Atlantic TV
> Freeport, Maine
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In a message dated 11/22/2004 3:28:49 PM Eastern Standard Time,
> MDileo0000@xxxxxxx writes:
> Thanks for the reply, Eric. Q505 and 541 are OK, changed them to be sure.
> also Q506 and Q507. As you mentioned, the tape transport operates
normally.
> Forcing the relay on brings up a normal picture and functions. The only
thing
> that
> is missing is the base voltage on Q801. The 12 vdc scan supply comes up
and
> seems to be shunted by Q506 or Q505. No schematic and no common sense on
> this.
> Anyone else have something? A scan of the HVT and relay cicuitry would
really
> help.
>
> Dominic DiLeo
> Atlantic TV
> Freeport, Maine
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
> In a message dated 11/22/04 1:13:53 PM Eastern Standard Time,
> tvman@xxxxxxxxxxxxxxx writes:
>
> << Hi Dominic is your tv like this..Eric
> PVM1368 VCR takes tape but no pwr.to TV. No relay Replace Q505 and Q541
> both 2SA733
> E M Electronics
> Deer Lake NL
> Canada
> tvman@xxxxxxxxxxxxxxx
> eric.manuel@xxxxxxxxx
> ----- Original Message -----
> From: <MDileo0000@xxxxxxx>
> To: <techassist@xxxxxxxxxxxxx>
> Sent: Monday, November 22, 2004 2:19 PM
> Subject: [TechAssist] Panasonic PV-M1368 RelayDriver Problem, manuf.'98
>
>
> > The base of Q801 relay driver does not see enough voltage at turn on
> > ~0.3vdc. Tracing back to the base across a resistor there is 4.0 vdc
that
> I assume
> > is coming from the micro. The base of Q801 is also tied to Q506 and Q507
> thru a
> > wire jumper and low value resistor. Lifting the jumper restores
sufficient
> > voltage to allow the set to function with no apparent loss of any
control.
> TV
> > and VCR operate normally.
> > Any tips or scan of the power supplies would be much appreciated.
Thanks
> to
> > all and Happy Thanksgiving.
> >
> > Dominic DiLeo
> > Atlantic TV
> > Freeport, Maine >>
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