Re: Help needed with JVC TV


"James254" <james254@xxxxxxxxxxxx> wrote in message
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> "Zman" <zman@xxxxxxxxx> wrote in message
> news:42a8573a$0$7585$afc38c87@xxxxxxxxxxxxxxxxxxxxxxx
> >
> > "James254" <james254@xxxxxxxxxxxx> wrote in message
> > news:42a806a5$0$13583$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> > > "Zman" <zman@xxxxxxxxx> wrote in message
> > > news:42a63303$0$30959$afc38c87@xxxxxxxxxxxxxxxxxxxxxxx
> > > > I performed a search on the internet a while back for information
> > > regarding
> > > > the problem of. "WHITE PICTURE WITH BLACK VERTICAL BAR RUNNING DOWN
> THE
> > > LEFT
> > > > HAND SIDE OF THE SCREEN" and found this fault listed on a site which
> > > > provided TV/VCR faults and solutions. Can't seem to find the link
now
> > > > though.
> <SNIP>
>
> > > >The make and model number if JVC AV-G25AV.
> > > >
> > > > Thanks for any help.
> > > >
> > > >
> > >
> > > Hi Zman,
> > >
> > > You don't clearly indicate that you are a technician and are aware
that
> TV
> > > sets contain very high voltages at dangerous currents. If you are not
> > aware
> > > of the risks involved please do not open the TV. Take it to a
> experienced
> > > technician for repair. The life you save may be your own...
> > >
> > > However, given the above warning you might like to try the following
> > >
> > > 1. Add a wire link between pin 2 and pin 7 of IC703 (The EEPROM)
> > > 2. With the customer's remote control (RM-C457) press the 'Display'
key.
> > >
> > > This should solve your problem.
> > >
> > > Hope this helps!
> > > James
> > >
> > >
> > Hi James,
> >
> > Yeah, I was a technician for approximately 4 years but that was over 7
> years
> > ago and haven't been in the industry since.
> > Thanks for the advice and the warning, problem is I don't have the
> original
> > remote so I'm not sure how I'm going to follow your instructions.
> > I have a universal remote I could probably use but I'm not sure how that

> > will work since there is no was of working out which key will end up
being
> > the "Display" key. I might just have to try all the buttons and hope one
> > works, but I sense that might end up being a disaster. Does this process
> of
> > pressing the "Display" key, while pin 2 and 7 are shorted, in some way
> > reprogram the EEPROM?
> >
> > I don't know what to make of this problem, EEPROM's were seldom found in
> > TV's back in the days I worked on them.
> >
> > Thanks again,
> >
> > John.
> >
> >
>
> Hi Zman,
>
> I'm not the designer so I can only guess what happens from experience with
> this model and later JVC designs. Pin 7 of IC703 is not connected to
> anything, it's floating. From what I can understand from the data*** the
> IC factory use this as a test pin. In later JVC designs the pin is shorted
> to ground.
>
> So the solution appears to be two steps.
>
> 1. Short circuit pin 7 to ground permanently. Pin 2 of IC703 is ground so
> this is the easiest way...
>
> 2. 'Reset' the EEPROM. This is done by pressing the 'Display' key on the
> customer remote control. The display key brings up and clears the
on-screen
> channel number. Doing this must force a change to a specific location in
the
> EEPROM and this resets the EEPROM.
>
> I understand that replacing the microcontroller or the EEPROM has the same
> effect. However when you replace the EEPROM you must perform a full
factory
> setup which involves putting the unit into test mode. To do this you need
> the customer's remote control!
>
> My feeling is that a universal remote just isn't going to cut it.
>
> You may get away with using a later model JVC remote control but this is
> only a guess...
>
> Hope this helps,
> James
>
>
>
Thanks for all the info and your suggestions James.

I'll give it a go :-)

John.


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