Hello All,
This message provides information on service menu
operation, color decoder adjustment (to correct
for red push), and the ability to utilize
separate picture control settings for the various
video inputs on a number of JVC televisions.
I authored this material to help those who are
currently considering a JVC television or for
those who already have one of the JVC's in
question. My only request is that if you repost
this information in part or total, you refernce
me as the author. I say this since I've aleady
seen a site that is, shall we say, strikingly
similar (dare I say, verbatim) to my posting on
another forum a week or so ago. That is, with
the exception of first person references and my
name removed from the document.
Hmmmm.....
Anyway, to the point. I put this information
together using an AV-36260 which I purchased a
few months back but should be applicable across
many of JVC's current models (those models built
on JVC's "AC" base chassis). In order
to help those doing searches on specific models,
I've listed the models that I am aware of which
currently use this chassis. They are:
AV-36230, AV-36260, AV-32230,
AV-32260, AV-27260, AV-36D202,
AV-36D302, AV-36D502, AV-32D202,
AV-32D302, AV-32D502, AV-27D502,
AV-27F702, AV-27F802
The service menus on all of these units should,
for the most part, be identical. Again, though,
my testing was done explicitly on the AV-36260.
Now, the AV-36260 (and other "AC" chassis units)
have the capability of using different black
level, white level, color saturation and hue set
points (among others) for each input mode of the
unit. The input modes are as follows:
"TV" - The antenna input.
"EXT" - The external inputs OTHER than
the component input.
"CMP" - The component input(s).
This is done by either having separate service
menu registers each holding the absolute value
of the parameter in question for the given input
mode or by using the value of the "TV" input mode
register combined with an offset register for the
input mode in question. An example of these two
methods would be the component input "CMP" black
level (brightness) and saturation (color). These
values are determined as:
COMPONENT INPUT
---------------
BLACK LEVEL = #1 (Brightness [TV mode])
+- #11 (CMP brightness)
COLOR = #13 (CMP Color)
I hate to be long winded about this, but the
service manual for the unit is less than clear
with regards to this point so I just wanted to
clarify it here. This can also be complicated by
the fact that you can specify different values
for black level, white level, saturation and hue
in the "set video status" user (not service) menu
and these are apparently used in all modes if the
"video status" (there's a button for it on the
remote) is set to CHOICE. Using the CHOICE video
status option though defeats the value of having
separate set points for each of the inputs so my
advise is not to use it. Leave the "video status"
in STANDARD mode and adjust the parameters of the
individual modes through the service menu.
Ok, so here's the procedure I use to adjust the
various display parameters in each of the input
modes. I did this using the AVIA DVD
(incidentally in a JVC XV-SA75GD player - not a
plug just a comment). The player supplied Svideo
and component input to the TV and fed Svideo to
my VCR which was used for supplying the modulated
signal for "TV" mode adjustments.
-Make sure the "video status" setting
mentioned above is in STANDARD mode.
-Connect your video sources to the
various inputs on the unit in question.
And now for the color decoder...
-Adjust the color decoder's MATRIX
settings
#36 R Y GAIN 000
#38 CD MATRIX 000
This should completely
eliminate red push for the
"TV" and "EXT" inputs.
#37 CMP R Y GAIN 000
#41 CMP CD MATRIX 000
This should completely
eliminate red push for the
"CMP" inputs.
Ok, so now I'll take a line from Emeril
in saying, "BAM", when you set CD MATRIX
to 000. In fact, I found that red was
somewhat underdriven and resettting the
R-Y gain to 000 compensated for this
with negligible affected on green and
blue. This said, there are still a
number of parameters to adjust...
-Set the unit's input to "TV" and set:
#1 Brightness (black level)
#2 Picture (white level)
#5 Detail
#3 Color (saturation)
#4 Tint (hue)
-Set the unit's input to one of the
external inputs (other than component)
and repeat the adjustments above this
time using the following registers
#6 EXT Brightness
#7 EXT Picture
#8 EXT Color
#9 EXT Tint
Remember, these are simply offsets to
the values in registers #1,2,4 and 5 so
they may be positive or negative as
opposed to absolute values.
-Set #10 EXT Detail
(not an offset register)
-Set the unit's input to component and
repeat the brightness and picture
adjustments
#11 CMP Bright
#12 CMP Picture
These are again offset values related to
registers #1 and 2 above.
-Set #13, 14 and 15 (not offset registers)
#13 CMP Color
#14 CMP Tint
#15 CMP Detail
Ok, you should now have black level, white level,
saturation and hue set properly in all modes and
have eliminated the unit's red push! Of course,
you mileage may vary but this worked well for me.
Ok, I'll snip the section in my usenet posts
about not mussing with the red, green or blue
screen and drive controls. You all should
already know this screws with overall white
balance and grey scale tracking so 'nuff said.
Use the CD MATRIX an R-Y GAIN registers instead.
There are a few other comments I can make about
the unit before closing. First, I did notice
some geometry distortion when setting the white
level on the unit. I backed off my white level
somewhat to reduce this, but it is still present
to some degree. Its not really discernible to me
in normal viewing, but is present none the less.
I don't know if this is just my unit or a general
issue with the power supply on this class of
chassis. I'd be interested in other's comments
on this.
Also, you actually have one additional group of
set points available to you through the theater
service sub-menu. Theater mode has its own
registers for all of the above parameters (black
level, white level, detail, saturation and hue)
and you should also be able to set different
white balance and gray scale tracking with the
theater mode as well (which you can also do for
each of the "TV", "EXT" and "CMP" modes above
though I didn't cover this in the configuration
procedure above). I thought I might use this for
ideal (dark room w/ only affect lighting) viewing
of the TV in component mode and use the component
mode values set in the procedure above for viewing
in bright (daylight) environments. Haven't done
anything with this yet though. Next rainy day
project...
Finally, this chassis also supports anamorphic
squeeze. This isn't a user menu setting, but can
be done quite easily through the service menu.
I will do a subsequent message on this since it
should also be applicable across the entire
"AC" chassis line. I posted this on USENET and
another forum a couple of weeks back and its
also made it to the afore referenced site...
Ok, I hope this information proves useful. I
think the JVC's based on this chassis are an
excellent value and with proper color decoding,
anamorphic squeeze and other features its really
a tough unit to beat. Also, my apologies if I
belabored the issue of reusing this info. The
site I mentioned just doesn't sit quite right
with me. Now my comment about the usual
disclaimers applying here. You should document
all of your service menu settings before making
any adjustments to them. Use with care!!
Dave Abel
--
P.S. I was curious to see how close JVC set the
color temperature on this unit to 6500K so
I'm putting together the poor man's color
analyzer with one of the ideal lume tubes.
I'll post the results if anyone's interested.
This message provides information on service menu
operation, color decoder adjustment (to correct
for red push), and the ability to utilize
separate picture control settings for the various
video inputs on a number of JVC televisions.
I authored this material to help those who are
currently considering a JVC television or for
those who already have one of the JVC's in
question. My only request is that if you repost
this information in part or total, you refernce
me as the author. I say this since I've aleady
seen a site that is, shall we say, strikingly
similar (dare I say, verbatim) to my posting on
another forum a week or so ago. That is, with
the exception of first person references and my
name removed from the document.
Hmmmm.....
Anyway, to the point. I put this information
together using an AV-36260 which I purchased a
few months back but should be applicable across
many of JVC's current models (those models built
on JVC's "AC" base chassis). In order
to help those doing searches on specific models,
I've listed the models that I am aware of which
currently use this chassis. They are:
AV-36230, AV-36260, AV-32230,
AV-32260, AV-27260, AV-36D202,
AV-36D302, AV-36D502, AV-32D202,
AV-32D302, AV-32D502, AV-27D502,
AV-27F702, AV-27F802
The service menus on all of these units should,
for the most part, be identical. Again, though,
my testing was done explicitly on the AV-36260.
Now, the AV-36260 (and other "AC" chassis units)
have the capability of using different black
level, white level, color saturation and hue set
points (among others) for each input mode of the
unit. The input modes are as follows:
"TV" - The antenna input.
"EXT" - The external inputs OTHER than
the component input.
"CMP" - The component input(s).
This is done by either having separate service
menu registers each holding the absolute value
of the parameter in question for the given input
mode or by using the value of the "TV" input mode
register combined with an offset register for the
input mode in question. An example of these two
methods would be the component input "CMP" black
level (brightness) and saturation (color). These
values are determined as:
COMPONENT INPUT
---------------
BLACK LEVEL = #1 (Brightness [TV mode])
+- #11 (CMP brightness)
COLOR = #13 (CMP Color)
I hate to be long winded about this, but the
service manual for the unit is less than clear
with regards to this point so I just wanted to
clarify it here. This can also be complicated by
the fact that you can specify different values
for black level, white level, saturation and hue
in the "set video status" user (not service) menu
and these are apparently used in all modes if the
"video status" (there's a button for it on the
remote) is set to CHOICE. Using the CHOICE video
status option though defeats the value of having
separate set points for each of the inputs so my
advise is not to use it. Leave the "video status"
in STANDARD mode and adjust the parameters of the
individual modes through the service menu.
Ok, so here's the procedure I use to adjust the
various display parameters in each of the input
modes. I did this using the AVIA DVD
(incidentally in a JVC XV-SA75GD player - not a
plug just a comment). The player supplied Svideo
and component input to the TV and fed Svideo to
my VCR which was used for supplying the modulated
signal for "TV" mode adjustments.
-Make sure the "video status" setting
mentioned above is in STANDARD mode.
-Connect your video sources to the
various inputs on the unit in question.
And now for the color decoder...
-Adjust the color decoder's MATRIX
settings
#36 R Y GAIN 000
#38 CD MATRIX 000
This should completely
eliminate red push for the
"TV" and "EXT" inputs.
#37 CMP R Y GAIN 000
#41 CMP CD MATRIX 000
This should completely
eliminate red push for the
"CMP" inputs.
Ok, so now I'll take a line from Emeril
in saying, "BAM", when you set CD MATRIX
to 000. In fact, I found that red was
somewhat underdriven and resettting the
R-Y gain to 000 compensated for this
with negligible affected on green and
blue. This said, there are still a
number of parameters to adjust...
-Set the unit's input to "TV" and set:
#1 Brightness (black level)
#2 Picture (white level)
#5 Detail
#3 Color (saturation)
#4 Tint (hue)
-Set the unit's input to one of the
external inputs (other than component)
and repeat the adjustments above this
time using the following registers
#6 EXT Brightness
#7 EXT Picture
#8 EXT Color
#9 EXT Tint
Remember, these are simply offsets to
the values in registers #1,2,4 and 5 so
they may be positive or negative as
opposed to absolute values.
-Set #10 EXT Detail
(not an offset register)
-Set the unit's input to component and
repeat the brightness and picture
adjustments
#11 CMP Bright
#12 CMP Picture
These are again offset values related to
registers #1 and 2 above.
-Set #13, 14 and 15 (not offset registers)
#13 CMP Color
#14 CMP Tint
#15 CMP Detail
Ok, you should now have black level, white level,
saturation and hue set properly in all modes and
have eliminated the unit's red push! Of course,
you mileage may vary but this worked well for me.
Ok, I'll snip the section in my usenet posts
about not mussing with the red, green or blue
screen and drive controls. You all should
already know this screws with overall white
balance and grey scale tracking so 'nuff said.
Use the CD MATRIX an R-Y GAIN registers instead.
There are a few other comments I can make about
the unit before closing. First, I did notice
some geometry distortion when setting the white
level on the unit. I backed off my white level
somewhat to reduce this, but it is still present
to some degree. Its not really discernible to me
in normal viewing, but is present none the less.
I don't know if this is just my unit or a general
issue with the power supply on this class of
chassis. I'd be interested in other's comments
on this.
Also, you actually have one additional group of
set points available to you through the theater
service sub-menu. Theater mode has its own
registers for all of the above parameters (black
level, white level, detail, saturation and hue)
and you should also be able to set different
white balance and gray scale tracking with the
theater mode as well (which you can also do for
each of the "TV", "EXT" and "CMP" modes above
though I didn't cover this in the configuration
procedure above). I thought I might use this for
ideal (dark room w/ only affect lighting) viewing
of the TV in component mode and use the component
mode values set in the procedure above for viewing
in bright (daylight) environments. Haven't done
anything with this yet though. Next rainy day
project...
Finally, this chassis also supports anamorphic
squeeze. This isn't a user menu setting, but can
be done quite easily through the service menu.
I will do a subsequent message on this since it
should also be applicable across the entire
"AC" chassis line. I posted this on USENET and
another forum a couple of weeks back and its
also made it to the afore referenced site...
Ok, I hope this information proves useful. I
think the JVC's based on this chassis are an
excellent value and with proper color decoding,
anamorphic squeeze and other features its really
a tough unit to beat. Also, my apologies if I
belabored the issue of reusing this info. The
site I mentioned just doesn't sit quite right
with me. Now my comment about the usual
disclaimers applying here. You should document
all of your service menu settings before making
any adjustments to them. Use with care!!
Dave Abel
--
P.S. I was curious to see how close JVC set the
color temperature on this unit to 6500K so
I'm putting together the poor man's color
analyzer with one of the ideal lume tubes.
I'll post the results if anyone's interested.
