Following in the footsteps of the LG tweak thread (thanks guys!), I have made similar modifications to my Samsung 51" D8000 with excellent results.
It would be a good idea to read through that thread before starting, take notes and photographs of all original settings and most importantly: Don't try this if you are uncomfortable servicing your own hardware(these tweaks obviously void any warranty you have) and take proper precautions when working around high voltage power supplies!
And of course AVSFORUMS nor the posters can be held legally responsible for any mishaps, panel misbehavior and non-reversible disasters, proceed at your own risk.
First the measurements:
PN51D8000 pre/post tweak measurements, these were done in two steps. In the first step I just adjusted the drive voltages in the second both the drive voltage and rising ramp (timing) were adjusted. The rising ramp adjustment (Yrr) had the largest effect.
|Pattern (measure black)||pre-tweak[ftL]||post-tweak[ftL] (voltage trims only)||post-tweak[ftL] (voltage+timing trims)|
|Full Field Black CS off||0.016||0.012||0.005 - 0.006|
|100% white window||---||0.012||0.005 - 0.006|
|APL(small)||--||0.012||0.005 - 0.006|
|Flashing color bars||--||0.028||0.012|
The black levels are at the measurement limit of my probe. Reviewers with high-end meters have measured this panel type (51") at 0.012 ftL so if anything my meter is probably reading a bit high pre-tweak (0.016 ftL). Final values are at or below the limit of the meter so the best that I can say is that the post-tweak black level is no higher than 0.005 - 0.006 ftL.
UPDATE: Confirmed with large area photodiode measurement: mll=0.0056 +/- 0.0002 ftL
|mll [ftL]||Contrast ratio|
|on/off [96Hz cinema smooth]||0.01||3000|
Here is another measurement of the improvement highlighting the performance with real material and measuring the black bars during 2.35 material.
Procedure I followed (refer to photographs linked below for location of trim pots):
1. Adjust Vs counterclockwise to reduce voltage from sticker reading of 205V
2. Adjust Vsc fully counterclockwise
3. Run the scrolling anti-IR pattern
4. Adjust Yrr clockwise in small increments until you see pixels misfires in the white portion of the scrolling pattern.
5. Back off a tad counterclockwise to prevent misfires.
Step 3 produces the most improvement so you could also try skipping 1 and 2.
Va, Ve, and Yfr were not touched.
Panel voltage and timing alignment info.
Vs/Va are on the power main supply board:
Vsc is on the upper half of the Y-Scan board left of the main power supply:
Yrr is on the lower half of the Y-Scan board:
-Some "sparkles" against the dark background on a cold start - screen clears up almost immediately.
-Nothing noticed in normal view so far.
Which models will have the available trim controls?
All panels will have the Vs and Vsc voltage pots for minor tweaking.
Yrr pot should be available on:
All B series panels.
All C series panels.
All 400 level D series.
All 51" panels (confirmed for D and E series, F?)
59" and 64" 550 series, probably. (confirmed)
59" and 64" 6500, 6900, maybe (one report 6500 does not have Yrr).
59" 7000 and 8000, probably not but there may be some out there (Samsung revised Y-scan board sometime in late 2010).
64" 7000 and 8000, probably not but there may be some out there (Samsung revised Y-scan board sometime in late 2010).
59" (D-series and below) (60" E series and above) and 64" models have moved the voltage controls under digital control - Models without the Yrr pot might be adjustable via logic board register.
My current voltages:
Edited by zoyd - 6/4/13 at 3:15am