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#81231 - 16/03/2002 09:22 Strange display curruption
Nodge
new poster

Registered: 29/03/2001
Posts: 13
Hi, received a second RioCar about a month ago for my backup unit. Anyway just got round to playing around properly with it, and I've noticed a strange curruption of the display.

A complete line of vertical pixels, forth line from the right, half illuminates when the pixels on the far left of the display are illuminated. This leaves a line visable when the display is set to "track", and produces some strange results on visuals.

I've attached two pics, although it's very hard to see the effect with these. It's far more noticable with the naked eye, esp when at night in the car.

Anybody seen this before? Need a return to Empeg? The unit was supplied by carplayer.com.

Many thanks!


Attachments
79118-1.jpg (112 downloads)


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#81232 - 16/03/2002 09:23 Re: Strange display curruption [Re: Nodge]
Nodge
new poster

Registered: 29/03/2001
Posts: 13
Here's another pic!


Attachments
79119-2.jpg (123 downloads)


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#81233 - 16/03/2002 11:12 Re: Strange display curruption [Re: Nodge]
tonyc
carpal tunnel

Registered: 27/06/1999
Posts: 7058
Loc: Pittsburgh, PA
Yup I have this one, too. Same pixels, fourth column from the right. It's so faint that I never bothered to ask about it here. In fact I think it's so dim that it's not one of the Empeg's 4 shades that it normally uses on the screen.

But it's definitely there. I'm not sure if it's a hardware problem or what.
_________________________
- Tony C
my empeg stuff

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#81234 - 16/03/2002 16:42 Re: Strange display curruption [Re: Nodge]
Audio
stranger

Registered: 11/02/2002
Posts: 45
Loc: Italy
Mine has the same pixel line as well, now that I' ve checked...
Doesn't bother me that much though... ;-)

Alberto
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http://albertov.tripod.com

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#81235 - 16/03/2002 16:47 Re: Strange display curruption [Re: Nodge]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14483
Loc: Canada
I don't see it, even with the same visuals running as in your pics, in a darkened room (AC power). But it's possible, I suppose.. the display hardware uses a rather peculiar memory layout, and may suffer some spillover under some condtions..

Hugo?

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#81236 - 17/03/2002 19:05 Re: Strange display curruption [Re: mlord]
tonyc
carpal tunnel

Registered: 27/06/1999
Posts: 7058
Loc: Pittsburgh, PA
I don't see it, even with the same visuals running as in your pics, in a darkened room (AC power). But it's possible, I suppose.. the display hardware uses a rather peculiar memory layout, and may suffer some spillover under some condtions..

FWIW the best way to see it is to use Track info mode. The pixels on mine are *very* faint but they're there.
_________________________
- Tony C
my empeg stuff

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#81237 - 18/03/2002 04:06 Re: Strange display curruption [Re: tonyc]
Nodge
new poster

Registered: 29/03/2001
Posts: 13
Yes mine is noticable on the track info screen too, the pixels illuminated correspond horizontally to the ones used on the far left. Mine are somewhere between 1/4 and 1/2 brightness, comparing to the four shades the Empeg uses, and so are really noticable. It tends to ruin quite a lot of the visuals.

The question is can this be sorted under warranty? I planned to use the MkIIa in my car, with the MkII as my spare, but until this is sorted I'm gonna have to keep using my MkII because this problem does ruin the look of the unit.

Thanks to everyone for their help!

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#81238 - 18/03/2002 09:35 Re: Strange display curruption [Re: mlord]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
I've seen this before too; it appears to be a problem within the VFD glass and may well affect all units. The shadow is so faint it's not really worth bothering about though, it's almost invisible through most front panels (but much more visible with no panel when indoors).

It's *not* the wrong data being clocked to the display, I believe the phantom illumination might be a design issue in the grid drivers of the actual VFD glass. It's definitely not a software issue though, the pixels would be fully illuminated in that case and not a fraction of the brightness of otherwise identical columns.

The thing to remember is this: each pair of columns in the VF is connected in parallel, but only emits light if the grid above the phosphor is powered. The display is scanned by scanning adjacent grid pairs and clocking in the pattern you want to see on the 64 pixels below the grids. You draw column 0 and 127 at the same time, then 1 & 2, 3 & 4 and so on.

It almost seems like one of the right-hand grids is getting partially powered when a left-hand grid pair are powered - this would appear to be a slight flaw in the chips embedded in the display glass.

Hugo

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#81239 - 18/03/2002 11:25 Re: Strange display curruption [Re: altman]
tonyc
carpal tunnel

Registered: 27/06/1999
Posts: 7058
Loc: Pittsburgh, PA
Well, there's our answer, people, "straight from the horse's mouth."

FAQ material, maybe? This falls into the "infrequently asked questions" category but as more people use clear and smoked lenses, it might become more frequent. I noticed it awhile back but it's such a faint line that I never bothered to ask.

Following the mantra that "you can always fix it in software" I guess the player software could just be rewritten to not write anything to column 0, that seems to be the one that triggers this situation. But this doesn't bother me that much so I wouldn't even bother with that.
_________________________
- Tony C
my empeg stuff

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