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 Post subject: [DVL-919E] Side A Crosstalk Problem
PostPosted: 10 Jan 2022, 18:31 
Honest fan
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Recently bought a DVL-919E on eBay - unfortunately the packing wasn't great, it took a bashing at the back where the turn mechanism sticks out.

Luckily I already had a 'parts donor' DVL-909 and I swapped the entire mechanism from that, except for its duff DVD laser, noisy motor and a damaged ribbon cable (one of the ones that wraps round the turn mechanism, that wasn't much fun to replace!) which came from the 'new' player.

So I've now ended up with a DVL-919E that works perfectly (hurrah!) except for some bad crosstalk towards the end of side A of CLV discs.

I've been adjusting the Side A tangential adjustment screw (LD), and it has some effect, but despite a lot of adjustments, small amounts at a time (very laborious with all the stop-eject-adjust-load-play stuff) I can't get rid of the crosstalk - it's never better than 'pretty bad'.

I can see the adjustment screw raises and lowers the side of the carriage assembly - that's doing its job. I thought it might be that the ribbon cable might be pushing the assembly up as it approached the edge of the disc - but it's not that.

In desperation I tried altering the Side A Centring - no improvements, so I set it back like it was.

I even swapped the whole LD laser carriage with my spare - exactly the same.

That left the variable resistors (which are slightly different on the 'E' model to those on the standard DVL-919) 'VR603' (Track) 'VR604' (Focus) 'VR607' (LD Tilt) and 'VR609' (DVD Tilt).

With nothing to lose, I tried twiddling each of these (except the DVD one) - but could really see no effect from any of them, so set them back again....

(As an aside, I wonder why the 919E only has a single LD Tilt adjustment, VR607, when the bog-standard 919 has one for each side, VR607/8?).

So it's baffling me. Even if the rail on which the carriage runs were warped, surely the tangential adjustment screw would have a 'perfect' position for the end of the disc, even if it then mucked up things at the start of the disc? But I've never found that sweet spot.

Any ideas gratefully received!

(another aside - after a long session of ejecting/playing/ejecting/playing, sometimes the player protests with the message "Just wait a moment" when it's taken in the disc. After a wait of about a minute, it starts spinning again and all is well... any idea what the message signifies? Something overheating?)
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 Post subject: Re: [DVL-919E] Side A Crosstalk Problem
PostPosted: 18 Jan 2022, 15:19 
Hardcore fan
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You can think of tangential correcting the level of crosstalk and tilt correcting the balance. In a not-so-literal example, if tangential is the X axis and tilt is Y (an imaginary line from disc label straight to edge of disc), origin would be zero crosstalk. Both need to be set correctly or you'll get crosstalk. You really need a test disc to set this, since it is impossible to truly minimize crosstalk without the vertical bar pattern. Without an oscilloscope, you can set tangential until crosstalk is minimized then set tilt to cleanup the rest.

I'd make sure chassis isn't bent as well.
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