Philips 41GR8840 : Convergence problems

[Guest]

Hi,

I've got a Philips 41GR8840 with general convergence failure. All colors are distroded on horizontal lines and I can't fix it because I don't have the potentiometers' fonction (there are around 40 of them).

Is there someone which know the procedure to make convergence of this TVC or the fonction of each potentiometers:

For red and blue colors, I have for each those potentiometers :

vskey, hskey, vamp, hrot, n/s, e/w, vpar, vlin, vkey, vrot, hlin, hpar, hkey, hamp, h3

For green, I only have N/S, VPAR, VLIN, VKEY and VROT so I can't set the horizontal linearity.

Regards, Jerome

[torbjorn]

If the tv suddenly got a convergence problem, then there is a "real" fault that should be repaired before you try to make any adjustments. But in case the convergence has become gradually worse during several years, or after transporting the tv, then you can try adjusting first.

Refer to the service manual of the tv chassis, there all adjustment details will be found. The chassis is apparently G110PTV, and that service manual is available for download at this site (eserviceinfo.com).

As there are fewer adjustments for green than for the other colors, you should first switch the other colors off, adjust the green raster for correct picture geometry using a test card or pattern generator, then switch one after another of the other colors on and adjust their geometry to converge with the green raster.
Usually, a cross-hatch or dot pattern is best for making convergence adjustments.

[VirusCrazy]

Hi,

thanks for reply.

I've exchanged all the capacitors on the convergence boards and it seems to be better.

I've also already downloaded the service manual but the problem is that there is only schematics, no real procedure for convergence adjustment like in the philips DPTV325 chassis.

Anyway, I will try to adjust with the new capacitors replaced (I've trie to change the convergence before exchanging them but I did wrote their initial positions before tuning them so it should be easier to redo the convergence now.

thanks