Post
by Falkentyne » 14 Aug 2015, 14:00
Just check the Benq section. There's plenty of posts and a lot of step by step guides that have been written that will get you going. I spent a lot of time writing things and I really don't want to spend 15 minutes doing it again when it's there (it's rather tedious). You just have to take some time to read up.
As far as the service menu, there are two of them (and this should be in a sticky):
Strobe settings/primary service menu: Power off, hold Menu (button #4 going from top to bottom) for 5 seconds, press power+menu then release power and then release menu.
Burn-in (factory menu): Button 3+4 for 5 seconds while powered off, press power on while holding button 3-4 down, release power, release buttons.
On the XL2411Z, button #4 is button #2 apparently (middle button+button 2 should still unlock the burn-in menu).
Regarding the strobe phase setting:
Default strobe phase from the factory is optimized for lowest input lag (+1 frame ahead). This is strobe phase 100. This was designed to function similarly to the Lightboost accelerated scanout type pattern, which has the top of the screen with the lowest/no crosstalk, but since benq blur reduction does NOT use accelerated scanout, this comes at expense of a LOT of strobe crosstalk (the entire strobe pulse between frames/screen pixel transitions, etc) at the bottom. Lightboost uses accelerated scanout, which pushes almost all of the strobe crosstalk off the screen from the bottom.
Vertical Total tweaks (E.g. VT 1500/VT 1502 (both 100 and 120hz; VT 1500 on XL2720Z for 120hz, both for 100hz)/VT 1498 (125hz), VT 1501 (85hz) emulate accelerated scanout by increasing the screen vertical blanking period, so the panel has more time to complete pixel transitions (within the strobe pulse), which is actually sort of a scaler trick, where the monitor scaler is tricked (by a higher vertical total) into working with a larger "Virtual" screen panel height (e.g. VT 1500 as far as crosstalk is concerned, is like the screen is working with a 1440p vertical size instead of a 1080p size). You can find this out (I don't know if this will work or show up in the XL2430T) but in V4 firmware for XL2411Z/XL2420Z/XL2720Z), using a VT 1500 tweak and entering the BURN IN menu shows the vertical screen size (height) as 1440p instead of 1080p. Without a VT Tweak it shows 1080 (e.g. 1920x1080). With a VT Tweak, it shows 1280x1440 (not sure why the horizontal is changed). This horizontal size again affects the monitor SCALER...native resolution is unaffected, besides crosstalk for blur reduction being reduced, BUT the horizontal size being shrunk like this causes the monitor OSD (picture advanced->display mode) not to scale correctly, and the "aspect" setting becomes available at 1920x1080 when it should be greyed out(sort of obvious...the scaler thinks it's working at 1280x1440).
This applies to the Z monitors-again I do NOT know how this affects the XL2430T. The VT tweaks STILL reduce strobe crosstalk by the same % as the Z series--about 25% at VT 1500 (which is the same pixel increase you get from going from 1080 to 1440 vertically) so you have to test the OSD scaling options yourself.
Anyway: The strobe phase settings were optimized for lowest input lag (strobe phase 100). The default in XL2430T (which is called "Area" in the OSD and strobe phase in the service menu) may be different defaults, but WITHOUT a VT Tweak, strobe phase 100 has lowest input lag but horrible crosstalk at the bottom of the screen.
Strobe phase 0 (instead of 100) raises input lag by exactly ONE frame (but improves crosstalk at the bottom but depending on strobe DUTY, adds a little at the top (which increases as strobe duty (persistence/intensity (OSD) is increased). at 60hz that's 16ms of added input lag. 8.3ms at 120hz and 6.9ms at 144 hz.
(apparently in the XL2430T, strobe DUTY values are REVERSED from the XL2420Z), so Intensity 0 is brightest screen while intensity 25 is dimmest screen. I do NOT know if intensity 0= strobe duty 0 or strobe duty 25, however.
When using a VT tweak, strobe phase 100 will shut off the backlight. You will need to lower the Area (phase) setting until you reach the point where the backlight turns on, and corresponds "backwards" to strobe duty 001 (REGARDLESS of what the existing duty is...), then lower the strobe phase until you get the persistence you want. (I explained this clearly in another post before).
For 125hz @ 1498 VT: Strobe phase 047=strobe duty 001 (048 strobe phase shuts off the backlight).
120hz @ 1500 VT: strobe phase 050=strobe duty 001 (051 shuts off the backlight).
100hz @ 1502 VT: strobe phase 059=duty 001 (060 shuts off the backlight).
91 hz@ 1502 VT (I think it's strobe phase 067).
85hz @ 1501 VT (I forgot? (069?)
As masterotaku said, with a VT tweak, increasing strobe phase past a certain point DECREASES the strobe duty until you reach the points I gave you above, where going past it turns off the backlight, because the persistence can't drop anymore).
So for absolute lowest input lag, you want to keep those values in mind.
(note if the backlight turns off, and you cant see anything, you can just turn off blur reduction).
probably failing it someway. 
