AVS Forum Special Member
Join Date: Apr 2000
Location: The Wilds Of Canada
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This should be the exact sort of fix that the cybermail requires as well. If it is the 10 vertically oriented noise bars.. that just sit there, and don't go anywhere.. or ever change, then it is the same problem. It comes from a different mounting, and different chip, but the same source. And, once again, it is a fraction of an ohm's resitance..which if you know anything about this sort of thing, is very small. But critical, as usual.
Basically, it is a certian number ofd ground references on the left side of the conexant 878 chip that act as 'reference points' for the contrast range and absolute black level. These work in conjunction with the dynamic characteristic of the AGC (automatic gain control) circuit. As the overall gain of th signal wanders, and the character of the signal wanders, the influence of the ground disurbance of the secondary clock (I2Cclock) can be seen to peak and then wane. Mostly it shows up in uniform colors and in scenes that are almost all black. The AGC circuit makes the bars really show up in the black scenes. On my cards, when this problem rears it's ugly head, it REALLY shows up. With it gone, the dynamic range I have put into the cards really comes to the fore and makes the inputs look very good. I was amazed at the fact that I was geting such clarity and depth from my old Lasrdiscs.
As far as abvilability, e-mail me for details.
IF you have one of my cards, and are not up to the task, and feel that YOUR particular card (some have the problem..some do not) could benifit from this, then send it to me. I will do some minor upgrades for a $20 fee, and fix this problem as well. If ti is a more recent card, I will fix the problem for free, but you will have to pay shipping.
If one has access to a soldering gun at all, I think that most can do this fix quite easily themselves, by just working with the soldering that needs to be done on the back of the card. As for the cybermail cards, I haven't looked too closely at the one I have yet. The secondary clock IS isolated, and out onm a limb, ground-wise..so it could easily need a bit of help to quiet it down.
[This message has been edited by KBK (edited 08-29-2001).]
"Never forget that only dead fish swim with the stream." -- Malcolm Muggeridge.