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Sony G420 retrace lines, adjustment??

J

J. Doe

Jan 1, 1970
0
My ~3 yr old Sony G420 19" monitor is working great, EXCEPT over the years
the brightness has crept up to where retrace lines are visible, even with
the front panel digital brightness gain nearly zero, and "black" = grey...
I lugged the monster down stairs to my shop (not fun retired with a bad back
& pinched nerves in the neck!), only to find two focus pots on the HV
transformer, NO master brightness adjustment seen anywhere......
I repaired a bunch of garden variety (i.e. cheap/average) monitors back in
the late 90's, until the prices made spending any time or $$ on them
impractical, and 99% had a handy dandy brightness and focus right there in
plain sight, with only a couple of exceptions that I recall.. SO - how does
one lower the overall brightness on a G420???
TIA

Cheers'n Beers all..
Don
 
A

Art

Jan 1, 1970
0
One of the pots on the LOPT should be the Screen adjust, the other Focus. Or
there actually may be a G-2 Adjust on the CRT Board.
 
J

J. Doe

Jan 1, 1970
0
Art said:
One of the pots on the LOPT should be the Screen adjust, the other
Focus. Or there actually may be a G-2 Adjust on the CRT Board.

naw, they're both focus, I checked that........ I couldn't find anything
else that might be applicable. In fact, there seems to be a conspicuous
lack of anything adjustable, at least without major intrusive efforts
(PIA!)....... Ah well, let it die a lingering peaceful death, and by then
flat screens will have improved even more, and dropped another 40% in
price.......
 
J

J. Doe

Jan 1, 1970
0
dkuhajda said:
Here is how YOU adjust the G2 on that Sony monitor.
1. You become Sony authorized warranty servicer for the monitor.
2. You spend approximately $4,000 on a service manual subscription.
3. You buy the Sony Digital Alignment software and the specific
interface for that monitor, around $250 total here.

That's what I expected to hear....... argghhhhhhhhhh
 
D

dkuhajda

Jan 1, 1970
0
Here is how YOU adjust the G2 on that Sony monitor.
1. You become Sony authorized warranty servicer for the monitor.
2. You spend approximately $4,000 on a service manual subscription.
3. You buy the Sony Digital Alignment software and the specific interface
for that monitor, around $250 total here.

I would be very suspicious of the 200V line filter capacitor being bad and
the video output voltage running too low.

A weak crt will also cause the same symptom as the AKB circuit cannot
properly compensate for the image.
 
G

George Jetson

Jan 1, 1970
0
J. Doe said:
That's what I expected to hear....... argghhhhhhhhhh
After searching for awhile I found this post about a very similar problem,
after I tried this mod on a Dell P1110 the problem was mostly solved. This
is a hack but may give you insight on improving your problem. I used a 14M
from spare parts and tacked it parallel with R459.



I have repaired over 500 Dell P1110
Most of the problems I have seen are for Excessively bright picture.
R459 is the best to Mod and Have found that 5.6M ohms to 7.5M ohms to be
the repair range depending on how bright the picture has become. The lower
the Value of R459 the darker the picture will become. I have noticed that
when a lower value is needed often the bightness adjustment will also
shift the picture color. Darker settings will shift to blue and brighter
settings will shift to red. I have not found a way to compensate or repair
this problem. I have a number of P1110 that have convergence problems
where the center of the picture is good but the sides and top/bottom are
off, front panel controls have no effect on edges of screen, and
convergence rings and yoke adjustment cannot restore good picture. This is
a problem with the video board on the bottom of chassis, I have swapped
this out and restored convergence. It's not always perfect as DAS
adjustment is need to align monitor.
 
J

J. Doe

Jan 1, 1970
0
George said:
After searching for awhile I found this post about a very similar
problem, after I tried this mod on a Dell P1110 the problem was
mostly solved. This is a hack but may give you insight on improving
your problem. I used a 14M from spare parts and tacked it parallel
with R459.

If things weren't sealed up like a sardine can AND I had a schematic there'd
be a chance for some jungle engineering, but so far things aren't bad enough
to go to all that trouble. Of course the chance of obtaining a schematic is:
#1 slim to none, and #2 would cost 25% the price of a new monitor.
Maybe later.. Thanks. d:->))
 
G

George Jetson

Jan 1, 1970
0
J. Doe said:
If things weren't sealed up like a sardine can AND I had a schematic
there'd be a chance for some jungle engineering, but so far things aren't
bad enough to go to all that trouble. Of course the chance of obtaining a
schematic is: #1 slim to none, and #2 would cost 25% the price of a new
monitor.
Maybe later.. Thanks. d:->))

Opps forgot to include, resistor in question was on the crt neck board and
very easy to reach. Removed cover, then 4 or 6 screws pulled 2 shields, the
resistor shows thru a cutout with pads on top. Maybe easy, maybe not
applicable, good luck.
 
J

J. Doe

Jan 1, 1970
0
George said:
Opps forgot to include, resistor in question was on the crt neck
board and very easy to reach. Removed cover, then 4 or 6 screws
pulled 2 shields, the resistor shows thru a cutout with pads on top. Maybe
easy, maybe not applicable, good luck.

Is the Dell P1110 a relabled Sony G420 (or 4XX series) so the nomenclature
is the same?? If so, I'll log this suggestion for later application the
next time I feel frisky enough to haul this beast down to the shop.. Right
now it's just noticable enough (dim retrace on dark backgrounds and not
quite black blacks) to get me paranoid about what it'll look like a little
later...
Of course just because you're paranoid doesn't mean you're not being
followed.......... d:->))
 
G

George Jetson

Jan 1, 1970
0
J. Doe said:
Is the Dell P1110 a relabled Sony G420 (or 4XX series) so the nomenclature
is the same?? If so, I'll log this suggestion for later application the
next time I feel frisky enough to haul this beast down to the shop..
Right now it's just noticable enough (dim retrace on dark backgrounds and
not quite black blacks) to get me paranoid about what it'll look like a
little later...
Of course just because you're paranoid doesn't mean you're not being
followed.......... d:->))


The one I repaired was a rebadged SONY, the rumors after a brief google
search indicate a G4xx or G500. There is a strong probablity they share
some or all the same boards. I am not a full time CRT tech so YMMV.
 
A

Andy Cuffe

Jan 1, 1970
0
My ~3 yr old Sony G420 19" monitor is working great, EXCEPT over the years
the brightness has crept up to where retrace lines are visible, even with
the front panel digital brightness gain nearly zero, and "black" = grey...
I lugged the monster down stairs to my shop (not fun retired with a bad back
& pinched nerves in the neck!), only to find two focus pots on the HV
transformer, NO master brightness adjustment seen anywhere......
I repaired a bunch of garden variety (i.e. cheap/average) monitors back in
the late 90's, until the prices made spending any time or $$ on them
impractical, and 99% had a handy dandy brightness and focus right there in
plain sight, with only a couple of exceptions that I recall.. SO - how does
one lower the overall brightness on a G420???
TIA

Cheers'n Beers all..
Don

Have you tried running the "color return" function in the color menu?
This fixes most sony monitors with this problem. If that fails to fix
it, then you will have to change a resistor value as another post
indicated. I don't know why these monitor go up in brightness as they
age. Be sure to run color return after you change the resistor.
Andy Cuffe
[email protected]
 
J

J. Doe

Jan 1, 1970
0
Andy said:
Have you tried running the "color return" function in the color menu?
This fixes most sony monitors with this problem. If that fails to fix
it, then you will have to change a resistor value as another post
indicated. I don't know why these monitor go up in brightness as they
age. Be sure to run color return after you change the resistor.
Andy Cuffe
[email protected]

Andy,
You are true genius!
Of course you could have simply stated RTFM!! d:->))
I remember seeing that option when I first got the monitor and ran through
the menus, but it only made the impression it was for color balance, and
since that has never been an issue per se, it wasn't given a second thought.
The manual did explain it also controled brilliance.. doh!
The result was absolutely phenominal!!! And that's no stretch - since I
also tweaked the focus (both of them :), it's like a new monitor! Blacks
are BLACK again, no retrace, great saturation, sharp as a tack, etc., etc...
It's amazing how things sloowwly deteriorate and you just don't see it until
one day you're saying, damn, this used to be a LOT better..........
Give me a shipping address and as a show of gratitude I'll send you six
kittens for your kids at Christmas!!

Cheers'n Beers.. [_])
Don
 
N

NSM

Jan 1, 1970
0
| Andy Cuffe wrote:
| >
| > Have you tried running the "color return" function in the color menu?
....
| Give me a shipping address and as a show of gratitude I'll send you six
| kittens for your kids at Christmas!!

Kittens? You haven't heard of beer?

N
 
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