I have a Vestel Clone which is Asda branded (ONN) PVR 160 and am experiencing a black line at the bottom of the screen on my 32" ONN LCD TV.

My software version is v3.7 Twin Record

Can this be resovled by accessing my service menu on my TV somehow or something else maybe?

I have looked on the internet on how to access this service menu on my TV to no avail....

Please help
Thanks
DJS
Last edited by Freeview_Viewer : 22-10-2007 at 08:20

Do you mean a single pixel line sort of thing, or is it quite a wide line, like letterboxing? I know that some TV screens are 16:10 rather than 16:9, so you get a slight letterboxing with widescreen broadcasts. Sometimes there is an option to fill the screen which actually stretches the picture vertically slightly, but gets rid of the letterboxing.

What I mean is I think this is an issue with Vestel built PVRs.
When my TV is set to 16:9, I have a black line at the bottom of the screen.

My Evesham on v3.7 has no line at the bottom on channels that aren't letterboxed. There's a chance my tv has minor overscan on non-digtal imputs though as I can't access my service menu, so not 100% ruled out

Even with the menu screens (e.g. EPG)? Did you perhaps have a T810 before, and if so was the black line bigger with that?

It's just that I reported this to Vestel long ago for the T810, and was surprised to find when my T816 box arrived in February that the black line (actually, it's the bottom of the TV picture that gets chopped off completely) was gone, and therefore assumed it was fixed in software (v1.9 back then). My suggestion for the fix was to move the output window down, since there was tons of overscan at the top of the screen, and not enough at the bottom - it may just be that it was not moved down enough and is somewhat marginal. Alternatively, it could be the processor chip - different revisions tend to be used in the T816.

The black line on my T810 wasn't so bad on my TV, but on my parent's Panasonic TV (CRT), the black line at the bottom is about 5mm high, which is very annoying. Tried my T816 on the same TV and the black line is gone, and as a consequence the day on the BBC weather graphics is now complete (bottom of the letters isn't missing).

Could you possibly supply me with a photo of this, to demonstrate the problem? Preferably with the channel set to BBC News 24 (with the white banner at the bottom of the screen). I'm interested to hear exactly how big the black line is.

My parents now have a T816 box, replacing their old T810 one, and the black line that was there with the T810 has now gone. Well, almost - depending on the contrast of the scene, there can be upto approximately one or two scanlines of black appearing at the bottom. So, I don't expect this is a hardware problem per se - the fix that Vestel made just needs some tweaking so that some more overscan is removed from the top, giving more at the bottom. The fix I originally proposed to Vestel was to add 10 scanlines - it seems this wasn't enough to cover all TVs. I'll reopen this issue and hopefully Vestel can tweak the fix accordingly, removing the black line on your TV too. But, as I mentioned, a photo would be a big help.

BTW, the problem is documented at http://pvrbugs.futaura.co.uk/view.php?id=59 (T810 with screenshots) and http://pvrbugs.futaura.co.uk/view.php?id=60 (T816). If anybody else has this problem with the T816 on their TV, please post your TV make and model number here.

Here are some photos of the black line on mt TV, though I have changed TVs since, and this one still has the problem

Few Pics here:-
http://aycu28.webshots.com/image/332...6781666_rs.jpg
http://aycu34.webshots.com/image/330...2793465_rs.jpg
http://aycu26.webshots.com/image/317...4700090_rs.jpg

Is this fixed in the new software updates?

or see my other thread for photos on my Thomson TUTVA Box with the same problem

http://www.digitalspy.co.uk/forums/s...d.php?t=682315

Those links don't work. I think you've pasted the condensed form.

Sorry about that, look at the link for the other thread

The problem was very noticable on Vestel T810 boxes, and equally on the Sagem PVRs using the same PVR chipset. Seeing as lots of PVRs have this problem, I guess they probably use the same chipset and it could be a hardware bug/quirk. Especially when you consider that the old Sagems using the PowerPC PVR chip did not have a black line, but the new ones using the same chip as the Vestel PVRs do have the black line. That said, not many chips are bug-free, and things can be worked around in software...

I reported the problem long ago for the T810, and when I got a T816 test box in February I was pleased to see the black line had gone. Unfortunately, because even the early software factory installed on the box had the bug fixed, I can't be sure if a workaround was added as per my suggestion, or whether the fix was in the hardware somewhere. My hunch is that it can be worked around in software, by moving the frame since the problem is that there is not enough overscan at the bottom of the screen, but way too much at the top. Even on the T816, the overscan at the bottom of the screen is probably a bit too tight, and although it's fine on my TV, on my parent's there is sometimes about 1 pixel row at the bottom that is black, depending on the picture brightness (compared to the T810 which had a whacking great 8mm or so black line at the bottom).

I've seen your other pictures - is the line only at the bottom (can't see the top on your photos)? On my parents' TV (a 19" Wharfedale), it is actually a 16:10 panel. What this means is that when they watch 16:9 broadcasts from their Wharfedale 250DTR they get a slight letterbox black line at the top and bottom of the screen. (Making up the extra "1" so to speak). What confuses things is that if they watch via the TV's built-in digital tuner, the picture appears to be full screen but it is actually stretched slightly vertically, and there is no option to get the correct proportion (ie with the black line at the top and bottom). 16:10 screens seem to be the norm for TVs up to about 22", and generally speaking 26" and above use true 16:9 panels.
Of course, your situation may be something different, but it might be worth checking the aspect ratio of your tv!

It is not a fault of the box.
Broadcasters using digital terrestrial use less active lines.
If you compare a analogue4:3 programmes with its digital equivalent you will see part of the picture is missing ( around 6-8 lines) The same is true for the start of the picture frame, and the active horizontal width is reduced.
Broadcasters hope that TV overscan would mask this but now with LCD and plasma tv,s this gap becomes noticable.
On Digital used to transmit 540 active lines ( analogue 576).
I did telephone On Digital several years ago about these blanked lines. The reply I got was it enabled them to transmit and extra TV service or radio station in the available bandwidth!

I disagree about it not being the boxes fault. I did a side-by-side comparison with my T810 and old Nokia Mediamaster. I used the engineering menu of my TV to move the display up, revealing the overscan at the bottom of the picture. The simple fact is that the picture output from the Vestel boxes, at least, is truncated at the bottom. The Nokia displayed more of the picture in the overscan area at the bottom. The problem is obvious when viewing News 24, for example, with the banner at the bottom of the screen. Given that this black line was greatly reduced with the T816, it clearly demonstrates the box is ultimately at fault.

What you say about 540 vs 576 lines is interesting though. Do you know if this is true for the rest of Europe? I mean, the software could be expecting 576 lines, with full overscan at the top and bottom, and the display centred assuming there are 576 lines, which might explain why the picture is framed incorrectly on the T810 and other brands of boxes, seeing as most PVRs are developed outside the UK for use in other countries.