Thread View: sci.electronics.repair
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Started by Sylvia Else
Mon, 06 Feb 2012 08:44
Grundig Satellit 300
Author: Sylvia Else
Date: Mon, 06 Feb 2012 08:44
Date: Mon, 06 Feb 2012 08:44
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After operating OK since the repairs I did after dropping a curtain pole on this radio a month or so back, the LCD is playing up. If I perform an operation that clears the display, and enter an 8 digit, it looks normal enough. If I enter a second 8 digit, some of the segments of both digits (the same ones in each case) become fainter. If I enter a third 8 digit, the segments become fainter still, and so on, until they're pretty much invisible. This suggests an issue with one (or more) of the backplanes. The signals going in look normal enough, and in particular the backplane signals don't change as I enter additional digits. Any thoughts before it ends up on the tip? Sylvia.
Re: Grundig Satellit 300
Author: N_Cook
Date: Mon, 06 Feb 2012 08:58
Date: Mon, 06 Feb 2012 08:58
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Sylvia Else <sylvia@not.here.invalid> wrote in message news:9p9i8dFk4bU1@mid.individual.net... > After operating OK since the repairs I did after dropping a curtain pole > on this radio a month or so back, the LCD is playing up. > > If I perform an operation that clears the display, and enter an 8 digit, > it looks normal enough. If I enter a second 8 digit, some of the > segments of both digits (the same ones in each case) become fainter. If > I enter a third 8 digit, the segments become fainter still, and so on, > until they're pretty much invisible. > > This suggests an issue with one (or more) of the backplanes. > > The signals going in look normal enough, and in particular the backplane > signals don't change as I enter additional digits. > > Any thoughts before it ends up on the tip? > > Sylvia. Is there a contrast control that got broken as well? What other LCD legends etc other than the main 8 digit display ?
Re: Grundig Satellit 300
Author: Sylvia Else
Date: Mon, 06 Feb 2012 12:51
Date: Mon, 06 Feb 2012 12:51
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On 6/02/2012 7:58 PM, N_Cook wrote: > Sylvia Else<sylvia@not.here.invalid> wrote in message > news:9p9i8dFk4bU1@mid.individual.net... >> After operating OK since the repairs I did after dropping a curtain pole >> on this radio a month or so back, the LCD is playing up. >> >> If I perform an operation that clears the display, and enter an 8 digit, >> it looks normal enough. If I enter a second 8 digit, some of the >> segments of both digits (the same ones in each case) become fainter. If >> I enter a third 8 digit, the segments become fainter still, and so on, >> until they're pretty much invisible. >> >> This suggests an issue with one (or more) of the backplanes. >> >> The signals going in look normal enough, and in particular the backplane >> signals don't change as I enter additional digits. >> >> Any thoughts before it ends up on the tip? >> >> Sylvia. > > Is there a contrast control that got broken as well? > What other LCD legends etc other than the main 8 digit display ? > > Can't see anything that adjusts contrast. The LCD doesn't have that much other than digits, but those that it has seem to work normally. The digits appear thus XXXXXX X X X X X X ...... . . . . . . XXXXXX Where XXX denotes segments that work, and ... denotes segments that don't. All the digits are failing in the same way, including a small digit that denotes a channel number. Since my original posting, I surmised, by cutting tracks, that these segments share a segment common, as do the top three. So then I connected them the other way around, with the result that the digits come out wrong or garbled, but the same three segments misbehaved. The connection to the LCD is via an eltroconductive rubber strip, which seems OK. Seems to me that the LCD itself is failing. Seems a strange failure mode though. Sylvia.
Re: Grundig Satellit 300
Author: N_Cook
Date: Mon, 06 Feb 2012 14:02
Date: Mon, 06 Feb 2012 14:02
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Sylvia Else <sylvia@not.here.invalid> wrote in message news:9pa0n7F1huU1@mid.individual.net... > On 6/02/2012 7:58 PM, N_Cook wrote: > > Sylvia Else<sylvia@not.here.invalid> wrote in message > > news:9p9i8dFk4bU1@mid.individual.net... > >> After operating OK since the repairs I did after dropping a curtain pole > >> on this radio a month or so back, the LCD is playing up. > >> > >> If I perform an operation that clears the display, and enter an 8 digit, > >> it looks normal enough. If I enter a second 8 digit, some of the > >> segments of both digits (the same ones in each case) become fainter. If > >> I enter a third 8 digit, the segments become fainter still, and so on, > >> until they're pretty much invisible. > >> > >> This suggests an issue with one (or more) of the backplanes. > >> > >> The signals going in look normal enough, and in particular the backplane > >> signals don't change as I enter additional digits. > >> > >> Any thoughts before it ends up on the tip? > >> > >> Sylvia. > > > > Is there a contrast control that got broken as well? > > What other LCD legends etc other than the main 8 digit display ? > > > > > > Can't see anything that adjusts contrast. > > The LCD doesn't have that much other than digits, but those that it has > seem to work normally. > > The digits appear thus > > > XXXXXX > X X > X X > X X > ...... > . . > . . > . . > XXXXXX > > Where XXX denotes segments that work, and ... denotes segments that don't. > > All the digits are failing in the same way, including a small digit that > denotes a channel number. > > Since my original posting, I surmised, by cutting tracks, that these > segments share a segment common, as do the top three. So then I > connected them the other way around, with the result that the digits > come out wrong or garbled, but the same three segments misbehaved. > > The connection to the LCD is via an eltroconductive rubber strip, which > seems OK. Seems to me that the LCD itself is failing. Seems a strange > failure mode though. > > Sylvia. So probably a crack in the glass at the backplane connections and so some silver loaded paint perhaps, if lucky and an exposed area.
Re: Grundig Satellit 300
Author: nesesu
Date: Mon, 06 Feb 2012 16:16
Date: Mon, 06 Feb 2012 16:16
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On Feb 6, 4:51 am, Sylvia Else <syl...@not.here.invalid> wrote: > On 6/02/2012 7:58 PM, N_Cook wrote: > > > > > > > Sylvia Else<syl...@not.here.invalid> wrote in message > >news:9p9i8dFk4bU1@mid.individual.net... > >> After operating OK since the repairs I did after dropping a curtain pole > >> on this radio a month or so back, the LCD is playing up. > > >> If I perform an operation that clears the display, and enter an 8 digit, > >> it looks normal enough. If I enter a second 8 digit, some of the > >> segments of both digits (the same ones in each case) become fainter. If > >> I enter a third 8 digit, the segments become fainter still, and so on, > >> until they're pretty much invisible. > > >> This suggests an issue with one (or more) of the backplanes. > > >> The signals going in look normal enough, and in particular the backplane > >> signals don't change as I enter additional digits. > > >> Any thoughts before it ends up on the tip? > > >> Sylvia. > > > Is there a contrast control that got broken as well? > > What other LCD legends etc other than the main 8 digit display ? > > Can't see anything that adjusts contrast. > > The LCD doesn't have that much other than digits, but those that it has > seem to work normally. > > The digits appear thus > > XXXXXX > X X > X X > X X > ...... > . . > . . > . . > XXXXXX > > Where XXX denotes segments that work, and ... denotes segments that don't. > > All the digits are failing in the same way, including a small digit that > denotes a channel number. > > Since my original posting, I surmised, by cutting tracks, that these > segments share a segment common, as do the top three. So then I > connected them the other way around, with the result that the digits > come out wrong or garbled, but the same three segments misbehaved. > > The connection to the LCD is via an eltroconductive rubber strip, which > seems OK. Seems to me that the LCD itself is failing. Seems a strange > failure mode though. > > Sylvia.- Hide quoted text - > > - Show quoted text - HAd a similar problem with an LCD on a controller pendant that was dropped. On desassembly of the display module, it was found that, as N Cook suggested, one corner of the display glass back plane was cracked, disconnecting two metalization tracks into the display. Unfortunatly, the breaks were under the epoxy seal between the top and bottom plates of the display, making a repair with silver condictive paint impossible. I was able to replace the display plate with an identical one from an obsolete pendant and get the newer one working properly. Neil S.
Re: Grundig Satellit 300
Author: Sylvia Else
Date: Mon, 06 Feb 2012 23:25
Date: Mon, 06 Feb 2012 23:25
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On 7/02/2012 1:02 AM, N_Cook wrote: > Sylvia Else<sylvia@not.here.invalid> wrote in message > news:9pa0n7F1huU1@mid.individual.net... >> On 6/02/2012 7:58 PM, N_Cook wrote: >>> Sylvia Else<sylvia@not.here.invalid> wrote in message >>> news:9p9i8dFk4bU1@mid.individual.net... >>>> After operating OK since the repairs I did after dropping a curtain > pole >>>> on this radio a month or so back, the LCD is playing up. >>>> >>>> If I perform an operation that clears the display, and enter an 8 > digit, >>>> it looks normal enough. If I enter a second 8 digit, some of the >>>> segments of both digits (the same ones in each case) become fainter. If >>>> I enter a third 8 digit, the segments become fainter still, and so on, >>>> until they're pretty much invisible. >>>> >>>> This suggests an issue with one (or more) of the backplanes. >>>> >>>> The signals going in look normal enough, and in particular the > backplane >>>> signals don't change as I enter additional digits. >>>> >>>> Any thoughts before it ends up on the tip? >>>> >>>> Sylvia. >>> >>> Is there a contrast control that got broken as well? >>> What other LCD legends etc other than the main 8 digit display ? >>> >>> >> >> Can't see anything that adjusts contrast. >> >> The LCD doesn't have that much other than digits, but those that it has >> seem to work normally. >> >> The digits appear thus >> >> >> XXXXXX >> X X >> X X >> X X >> ...... >> . . >> . . >> . . >> XXXXXX >> >> Where XXX denotes segments that work, and ... denotes segments that don't. >> >> All the digits are failing in the same way, including a small digit that >> denotes a channel number. >> >> Since my original posting, I surmised, by cutting tracks, that these >> segments share a segment common, as do the top three. So then I >> connected them the other way around, with the result that the digits >> come out wrong or garbled, but the same three segments misbehaved. >> >> The connection to the LCD is via an eltroconductive rubber strip, which >> seems OK. Seems to me that the LCD itself is failing. Seems a strange >> failure mode though. >> >> Sylvia. > > So probably a crack in the glass at the backplane connections Not entirely inconsistent with dropping a curtain rail on it, I suppose :( > and so some > silver loaded paint > perhaps, if lucky and an exposed area. I can't see any defects. Sylvia.
Re: Grundig Satellit 300
Author: Yaputya Leftlegin
Date: Mon, 06 Feb 2012 23:30
Date: Mon, 06 Feb 2012 23:30
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"Sylvia Else" <sylvia@not.here.invalid> wrote in message news:9p9i8dFk4bU1@mid.individual.net... > After operating OK since the repairs I did after dropping a curtain pole on this radio a month or so back, the LCD is playing up. > > If I perform an operation that clears the display, and enter an 8 digit, it looks normal enough. If I enter a second 8 digit, some > of the segments of both digits (the same ones in each case) become fainter. If I enter a third 8 digit, the segments become > fainter still, and so on, until they're pretty much invisible. > > This suggests an issue with one (or more) of the backplanes. > > The signals going in look normal enough, and in particular the backplane signals don't change as I enter additional digits. > > Any thoughts before it ends up on the tip? > > Sylvia. I have always found faulty LCDs to be unrepairable. They are too flimsy in construction, high impedance tracks etc, If its got a clock function, you might salvage a 32kHz crystal. Otherwise the tip.
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