LG 50PS3000 repaired but still with problems.

[satinser]

Have repaired a number of these in the past nearly all have been the usual problem of red haze and corrected by the fitting of the repair kit available.
Got one at the moment though where I've fitted the kit but still have picture problems (solarized picture). Have checked all the voltages and there all as they should be. Also tried Y-SUS set up and set down adjustments but still have the solarized image. Have also discovered that when the power connector from the PSU is removed from the X-SUS the picture remains exactly the same as when its connected. Any ideas as to possible cause? Also be grateful if anyone could confirm that zener diode referenced ZD201 is an IN5245.

[ReeceyBurger123]

Re: LG 50PS3000 repaired but still with problems.

Have you checked the Z bias voltage on the Zsus I will link a thread were the transistor that drives the Z bias tested good but was bad in circuit ?

[satinser]

Re: LG 50PS3000 repaired but still with problems.

Thanks for your reply. Yes the z bias reads 97v as listed on the label. With or without connector from PSU (p101) connected!

[satinser]

Re: LG 50PS3000 repaired but still with problems.

Just changed Q15 (51n25) in case it was reading ok but still leaky with slightly improved 77n33. The result afraid is still the same. Beginning to think it has to be a control board issue. Is there a chance that when the x-sus went faulty it damaged the control board? This seems different to normal maldischarge its more like tcon failure on an LCD tv and no amount of adjustment of pots will remove the solarized image.

[ReeceyBurger123]

Re: LG 50PS3000 repaired but still with problems.

Hmm I repaired one a few days ago with a different fault however I did read up online that all the 100uf 25v caps on the control board can go faulty and cause issues similar to what you have described.

[tom66]

Re: LG 50PS3000 repaired but still with problems.

If you have a scope, check both the Y and Z outputs look good.

[satinser]

Re: LG 50PS3000 repaired but still with problems.

Already changed the control board caps a few days ago thinking that might correct the problem. Afraid it didnt. I saw your video a few days ago regarding bad solder joints on AV board. Very helpful if you've got intermittent faults.

[satinser]

Re: LG 50PS3000 repaired but still with problems.

No afraid I haven't. Am looking into getting one though! Changed the y-sus board with a known good one just to test but didn't make a difference. Regarding the x-sus every component that can be checked has been checked all are good. So although unable to scope am pretty certain that output from both boards is good.