DVD963SA Digital Coaxial Out

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Hi There
(First time posting, not even that long lurking, but tinkerer for as long as I can remember!)
I was having a problem with my Philips DVD 963SA digital coaxial output occasionally skipping and it was getting a lot worse - yet the optical output was always perfect. Also I kept getting little electric shocks from touching the end of my coax digital cable (but not when plugged into my DAB radio coax output) - I know to stop these shocks I could stop touching the end of my cable, but I figured it probable shouldn't do that and it was a symptom of something wrong!

So after finding the service manual I worked out that it could only be a couple causing the problem since everything with the optical and coaxial digital outputs are the same. So I took it apart and had a look - and everything looked fine. There was one bit (number 5607) that was about 8mm x 8mm x 6mm square with a round centre bit with a slot in it - so I put a screwdriver in the slot and turned it about 30 degrees. I then plugged my coax cable into my DAC and it has just worked perfectly for 2 CDs - hurrah! But I am curious what I have just altered. The symbol looks like a transformer, but that should have two thin lines in the middle rather than one fat line. Also I would like to know if there is a value this (maybe) transformer should be set to. I cannot find any values in the manual, but then again I don't really know what I'm looking for!

I haven't put it all back together yet, so I could also be one of those things that works while everything is apart, but then doesn't once the dozen screws and cover are back in place!

Thanks in advance!
 

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OK, after plugging everything back in and putting it on the shelf it started playing up again. So this evening I had another look at it, but found out it was fine when I tested it on the floor?! So eventually I've worked out the problem is noise coming down the TV aerial, through my freeview box, into the TV, and out of the TV into my DVD963SA SCART lead - unplugging any of these connections instantly solves the noisy signal. My TV reception has got worse in the last few months and have been meaning to sort it out, but now I've got a real reason. Oddly enough though the problem is solved by either switching the TV on, or properly switching it off - just not leaving it on standby?!?

Also had a bit of read though past posts about modding the 963SA, especially the coaxial output - but got well and truly baffled, so that may be something that gets left until I have more time and knowledge!
 
Beautiful groundloops...

Hi,

I think your problem is related to your tv that is double insulated. What happens is that there is a voltage diffrence between the ground on the tv and your dvdplayer. It can give strange faults. Also, that explains the shock you recived by tuching the Coax cable. When you are using toslink you have a galvanic isolation, and therfore no groundloops can emerge.

If you have cable tv, it can also make thing worse becouse of groundloops. I built a simple high bandwith isolation transformer between the cable-tv and vcr. It has worked great ever since.

Best regards,

Magnus
 
I did sort this out in the end without having to take anything apart.

Magnus was right - Thanks! It was a groundloop problem caused by both the TV and the freeview PVR box 'ganging up' on either the DVD player or probably the DAC (via the DVD). It was OK if I unplugged the DVD SCART from the TV, or unplugged the freeview box SCART from the TV, or even plugged the DVD SCART into the PVR, but not the TV - obviously non of these were acceptable. But I did get a SCART switch box (which I'd been wanting for a while) and that has separated the SCARTs enough for there not to be a problem.

So it wasn't really diyAudio worthy in the end, but at least it is sorted! And I now know more about groundloops than I really care to!

Cheers
 
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