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36PW9607 distoted picture in 4:3

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Old 05-07-2002, 6:26 PM   #1
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36PW9607 distoted picture in 4:3

Got a Phillips PW369607 and the picture quality with Pixel Plus is amazing. But being a newbie to all things AV, I'm confused as to whether there is a problem. When viewing something in 4:3 mode the lack bands at the sides noticeably curve in at the middle. If there is an image of excessive brightness too the top or bottom will splay out - by as much as an inch or so.

Viewing in widescreen, a similar thing occurs. Most straight lines in images appear OK. But if there is suddenly a shot of a window frame with bright sky, the edges visibly bend out & distort. Even the sky digibox EPG distorts when on screen.

Anyone got any solutions for this? Is it something fixable or am I just expecting too much?
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Old 05-07-2002, 7:11 PM   #2
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Sugarhiccup,
The problem you describe is quite common. It can be reduced but still 4:3 edge of pictures can vary in linearity. Perfection is rare.
It's a new set, best call the engineer from your supplier, the set can be optimised.
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Old 08-07-2002, 11:12 AM   #3
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Actually, what you're describing is caused by pixel plus, and the way it is increasing the resolution... you will notice the geometry goes off with high contrast areas... if you turn it back to 100hz, it will stop... slightly annoying, but still, I dont turn it off...
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Old 08-07-2002, 12:48 PM   #4
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I have the same problem as Sugarhiccup and if that really is the case that its caused by Pixel Plus then I've got John Lewis replacing bits of my TV for nothing.

According to the repairers they've identified a faulty part in mine and are busy replacing it. It'll be interesting to see if it comes back with the same problem.

I'll keep you posted.
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Old 08-07-2002, 4:23 PM   #5
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Interesting... did yours still do it if you revert to 100hz, rather than pixel plus??? Also, you can see the effect, if you goto the menu and decrease the contrast, then increase it... whilst increasing it the screen should move/distort? I assume this is because pixel plus works after the picture preferences are set...
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Old 08-07-2002, 7:27 PM   #6
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Set to return on Thursday so i'll let you know then.
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Old 08-07-2002, 9:56 PM   #7
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Quote:
I assume this is because pixel plus works after the picture preferences are set...
This is interesting, because at least the Natural Motion sets perform processing in the following sometimes illogical order:

Analog pre-processing:
* RF demodulation or input selection
* Y/C separation with comb filtering if available
* Component separation or RGB to YUV conversion

Digital processing:
* A/D conversion 16MHz
* PALplus decoding if available
* Horizontal scaling including zoom and parabolic stretch
* DNR coring
* Histogram modification Dynamic Contrast
* DNR motion compensated
* Natural Motion or median flicker filtering
* Vertical sharpness
* Vertical scaling including zoom and scroll
* Horizontal sharpness
* Color Transient Improvement (CTI) when applicable
* D/A conversion 32 or 64 MHz

Analog post-processing:
* Black stretch
* Ambient light adjustment
* Luminance Transient Improvement (LTP)
* Color Enhancement
* Saturation adjustment
* YUV to RGB conversion
* Contrast adjustment
* Brightness adjustment
* Blue stretch

By this we can tell that a few things are done in a strange order; for instance horizontal downscaling to 4:3 and Super Zoom stretching is done before Natural Motion. This undoubtedly must affect its efficiency. It can be told that also Dynamic Contrast is performed before Natural Motion.

What is interesting about the Pixel Plus sets is that in order to double the output rate from 32 to 64MHz, either a.) horizontal scaling must be performed after Natural Motion, b.) the Natural Motion processor must accept a 32MHz input rate rather than 16MHz, or c.) there must be an additional oversampling step before D/A conversion.

I am sure the output processor is the same as before though. The geometry problems most likely are caused by the unusual vertical frequency (75Hz interlaced). Does a similar problem appear in the Double Lines mode (50Hz progressive)?

Last edited by Zacabeb; 08-07-2002 at 10:01 PM.
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Old 09-07-2002, 6:29 AM   #8
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Actually I am wrong... just looking at the set, is does do it in 100hz and double lines mode... but to a lesser extent than in pixel plus mode... BTW, its not just 4:3 its just you notice that more because the edges are visable...
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Old 09-07-2002, 12:21 PM   #9
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Unhappy

Quote:
Actually I am wrong... just looking at the set, is does do it in 100hz and double lines mode... but to a lesser extent than in pixel plus mode... BTW, its not just 4:3 its just you notice that more because the edges are visable...
Sorry just to be clear here, but are you saying your Phillips splays outwards by as much as an inch when displaying bright images?

Just trying to work out whether mine and Sugarhiccups are just "normal for Pixel Plus" or worse than average and therefore likely to be improved by a bit of geometry correction in the service menu.

I spoke to JL and the part they replaced on mine was supposedly the mains plug and lead! According to them it was damaged. It wasn't when I left my house though. Gawd knows what else they've done to it :-(
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Old 09-07-2002, 12:30 PM   #10
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I probably wouldnt have said an inch, but it is a definately noticable bend, splaying out towards the top and bottom of the screen...
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Old 11-07-2002, 3:25 PM   #11
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Unhappy

Got the TV back from John Lewis with exactly the same fault. In fact none of the values in the service menu have altered so I wonder if they even bothered trying to fix it. JLs repairers claim its a feature of this model therefore there's no point replacing it with another one the same. I can either choose a different model or have my money back.

I'm going to have a bash in the service menu myself before I admit defeat, but otherwise I'm looking for a new telly.

Given the number of people in here complaining about geometry issues with the 9617 then I guess JL may have a point. I may have an extreme example, but a lot of people don't seem to be happy. I guess how unhappy you are depends on what you personally believe a television that costs over a £1000 should look like.
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Old 11-07-2002, 3:28 PM   #12
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I've mailed Philips asking if its a known Feature... see if they reply...
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Old 11-07-2002, 3:29 PM   #13
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Oh yeah, also, the problem is, there is no better TV... RP wont cut it, 32 is too small, and there arent any better 36" CRT's... I'll stick with this and get a projector eventually
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Old 11-07-2002, 3:46 PM   #14
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Thing is, mine is the 28" version. Any alternatives you'd suggest looking at?

I might try phoning Phillips myself tomorrow ask what they think.

What email address you using for them? I could always send them my picture of the screen at its worst.
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Old 11-07-2002, 3:56 PM   #15
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I just posted from their UK customer service page... ringing might get a better response.
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Old 11-07-2002, 5:56 PM   #16
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i gave up with televisions for watching dvd's. got a projector instead, so only use tele for sky and video. Would never buy an expensive tele. As the posts say most geometry is rubbish.
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