Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to sci.electronics.repair
No Name
 
Posts: n/a
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

A challenge indeed......

What's known good: Each of the three projectors (red, green, blue) are
fully operable and in focus. Audio is unaffected and functions well.

The symptom is akin to the effect viewed as a partial signal block from HBO
in the late 1970's. where the picture shows up on screen with a wavy
horizontal flickering side to side motion. Depending upon the input signal
strength, the horizontal wavering strengthens as the signal gets stronger.

When using an antenna ( tested both antenna 1 input and antenna 2 input),
Channel 8 can receive marginal reception as the the channel is broadcasted
from 45 miles away. Some snow (weak signal indication), a little spotty
(microwave background distortion), but very few wavering lines as compared
to viewing a VCR/DVD input. All other channels are too distant to receive (I
have not activated cable TV yet). On channels without formatted broadcasted
signal received ( snow microwaves only), there is no indication of wavering
lines at all, and no indication of a malfunction.

With the input coming from either video 1 or video 2 (front and back tested)
having an 8mm camera connected to the TV, and active, and panning the lense
to the kitchen (not so bright), horizontal distortion exists. Then when
panning the 8mm camera to view through the window outside in the bright
sunlight, the distortion intensifies and the video output on the TV screen
becomes unrecognizable.

Without any signal input showing up on the screen, in the case of the full
screen TV setup menus, all text colors and text are sharp and background
color is picture prefect. This is also the case when the vhs is connected
and the stop button is pressed) with a tape active but not playing. The
output is the pretty blue blank screen (normal attribute in this scenario)
and the display statistics (date, time, position counter) appear in picture
perfectly clear white lettering.

If you have any TV experiences / thoughts to share (however
trivial they may appear), I'd appreciate your input.

Many Thanks,
Ken





  #2   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,569
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

On Sat, 11 Oct 2008 16:24:09 -0600, put
finger to keyboard and composed:

The symptom is akin to the effect viewed as a partial signal block from HBO
in the late 1970's. where the picture shows up on screen with a wavy
horizontal flickering side to side motion. Depending upon the input signal
strength, the horizontal wavering strengthens as the signal gets stronger.


Your set uses the VZ1 chassis.

Maybe the following repair tip applies to you.

Projection Repair Tips (page 2):
http://124.106.125.72/tv%20vcr%20rep.../project02.htm

Mitsubishi model VS40VA2 chassis VZ1

Symptom:
Washed out video - dark picture with bending and tearing - looks like
AGC problem but problem is also on video input

Fix:
Check/replace C7001 (4.7uf @ 35v), C7011 & C7027 (2.2uf @ 35v)

BTW, I ignored your first post because (1) its size flagged it as
spam, and (2) it was posted to the wrong group. And now you have
reposted this message twice to the same group.

Here's a friendly tip. Take some time to acquaint yourself with
Netiquette as it applies to Usenet. You will get a much better
response to your questions if you do.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
  #3   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 265
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

wrote in message
m...
A challenge indeed......

What's known good: Each of the three projectors (red, green, blue) are
fully operable and in focus. Audio is unaffected and functions well.

The symptom is akin to the effect viewed as a partial signal block from
HBO
in the late 1970's. where the picture shows up on screen with a wavy
horizontal flickering side to side motion. Depending upon the input signal
strength, the horizontal wavering strengthens as the signal gets stronger.

When using an antenna ( tested both antenna 1 input and antenna 2 input),
Channel 8 can receive marginal reception as the the channel is broadcasted
from 45 miles away. Some snow (weak signal indication), a little spotty
(microwave background distortion), but very few wavering lines as compared
to viewing a VCR/DVD input. All other channels are too distant to receive
(I
have not activated cable TV yet). On channels without formatted
broadcasted
signal received ( snow microwaves only), there is no indication of
wavering
lines at all, and no indication of a malfunction.

With the input coming from either video 1 or video 2 (front and back
tested)
having an 8mm camera connected to the TV, and active, and panning the
lense
to the kitchen (not so bright), horizontal distortion exists. Then when
panning the 8mm camera to view through the window outside in the bright
sunlight, the distortion intensifies and the video output on the TV screen
becomes unrecognizable.

Without any signal input showing up on the screen, in the case of the
full
screen TV setup menus, all text colors and text are sharp and background
color is picture prefect. This is also the case when the vhs is connected
and the stop button is pressed) with a tape active but not playing. The
output is the pretty blue blank screen (normal attribute in this scenario)
and the display statistics (date, time, position counter) appear in
picture
perfectly clear white lettering.

If you have any TV experiences / thoughts to share (however
trivial they may appear), I'd appreciate your input.

Many Thanks,
Ken







Search for info on the PIP bypass for this set. You have leaky caps on the
PIP module.

Leonard

  #4   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 265
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

wrote in message
m...
Leonard, Thanks. You are dead on... "Search for info on the PIP bypass for
this set. You have leaky caps on the PIP module".-- the caps WERE
leaking.
I used 91% isopropyl alcohol and a firm new 1" paint brush and cleaned off
of the entire PIP (930B552). Then, I put the PIP on my car dashboard in
the
warm Sun for 2 hours before continuing. I made JPS's of every step I've
taken and am willing to send the pre-snot and post snot pics, and or all
other boards to anyone who requests analyzing them.

On the PIP, under the shield, I adjusted LO7102 & LO7101 (blk) clockwise
to
where they stopped. I also flirted with VR7002 & VR7001 (blu) and acquired
some improvement, but not much. Each time, I unplugged 110v, took the PIP
board out, adjusted, reseated, replugged 100v., and re-powered on to view.
Could I flirt with adjusting them while live?

What about rotational adjustments on the main board? Any advise?

Leonard, Here a current list of specs I've been able to match up:

brand ---------------------- Mitsubishi
model ---------------------- VS-45VA1
base manual ---------------- VS-45VA2
chassis---------------------- VZ1
year------------------------- 1992
service adjust code-option--- 008
service adjust code-video pip 007
convergence adjust code ---- 009
Line = 83MI
Item (OEM) Description
========== ==============
935D162002 Side PCC
935D157001 Display
935D156001 Control Board
935D155001 PreAmp
935D154001 Front Board
935D153001 FS
935D152002 Terminal Board
935C442002 PCC
935C441002 Signal Board
935C440001 CRT Assy.
935C439001 Power Sub
935C438002 Convergence Board
935C437002 Main Board
930B552001 PIP

I do not understand these terminologies or the implications "service
adjust
code option 008", "service adjust code video pip 007" , "convergence
adjust
code 009", and "Line = 83MI". I've spent the day scouring the net for part
affiliation, and am looking for more insight.

Meat Plow, you say "You could always shotgun it by replacing the entire
video processing circuitry if you can determine where it is and find a
refurbed sub." Thanks Meat Plow, It's sounds like something I might
ultimately consider, but I'm not sure what "shotgun" and refurb "sub"
means
(power sub?) .

Thanks Franc. What is "AGC"? Automatic gain control ??? if it is what do I
look for ? Is it replaceable, or is it possible to bypass also? Or should
I
rule it out until the PIP issue is resolved?

Leonard, I may very well attempt a PIP bypass (if not replacemet). I found
web documentation for a potential bypass at the main board PIP blue
connector "GE", pinout 5(+) to 11, and 7(+) to 9, 2 - 4.7 @ 50 volts. HELP
on this!!! What does " 2 - 4.7" mean??? ... The pic is located at
http://members.aol.com/philselectron...ages/pipby.jpg

Thanks for your guidance,
Ken




"Leonard Caillouet" wrote in message
...
Search for info on the PIP bypass for this set. You have leaky caps on

the
PIP module.

Leonard




Just bypass the PIP module. Two caps and you are done.

Leonard

  #5   Report Post  
Posted to sci.electronics.repair
No Name
 
Posts: n/a
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

Leonard, Thanks. You are dead on... "Search for info on the PIP bypass for
this set. You have leaky caps on the PIP module".-- the caps WERE leaking.
I used 91% isopropyl alcohol and a firm new 1" paint brush and cleaned off
of the entire PIP (930B552). Then, I put the PIP on my car dashboard in the
warm Sun for 2 hours before continuing. I made JPS's of every step I've
taken and am willing to send the pre-snot and post snot pics, and or all
other boards to anyone who requests analyzing them.

On the PIP, under the shield, I adjusted LO7102 & LO7101 (blk) clockwise to
where they stopped. I also flirted with VR7002 & VR7001 (blu) and acquired
some improvement, but not much. Each time, I unplugged 110v, took the PIP
board out, adjusted, reseated, replugged 100v., and re-powered on to view.
Could I flirt with adjusting them while live?

What about rotational adjustments on the main board? Any advise?

Leonard, Here a current list of specs I've been able to match up:

brand ---------------------- Mitsubishi
model ---------------------- VS-45VA1
base manual ---------------- VS-45VA2
chassis---------------------- VZ1
year------------------------- 1992
service adjust code-option--- 008
service adjust code-video pip 007
convergence adjust code ---- 009
Line = 83MI
Item (OEM) Description
========== ==============
935D162002 Side PCC
935D157001 Display
935D156001 Control Board
935D155001 PreAmp
935D154001 Front Board
935D153001 FS
935D152002 Terminal Board
935C442002 PCC
935C441002 Signal Board
935C440001 CRT Assy.
935C439001 Power Sub
935C438002 Convergence Board
935C437002 Main Board
930B552001 PIP

I do not understand these terminologies or the implications "service adjust
code option 008", "service adjust code video pip 007" , "convergence adjust
code 009", and "Line = 83MI". I've spent the day scouring the net for part
affiliation, and am looking for more insight.

Meat Plow, you say "You could always shotgun it by replacing the entire
video processing circuitry if you can determine where it is and find a
refurbed sub." Thanks Meat Plow, It's sounds like something I might
ultimately consider, but I'm not sure what "shotgun" and refurb "sub" means
(power sub?) .

Thanks Franc. What is "AGC"? Automatic gain control ??? if it is what do I
look for ? Is it replaceable, or is it possible to bypass also? Or should I
rule it out until the PIP issue is resolved?

Leonard, I may very well attempt a PIP bypass (if not replacemet). I found
web documentation for a potential bypass at the main board PIP blue
connector "GE", pinout 5(+) to 11, and 7(+) to 9, 2 - 4.7 @ 50 volts. HELP
on this!!! What does " 2 - 4.7" mean??? ... The pic is located at
http://members.aol.com/philselectron...ages/pipby.jpg

Thanks for your guidance,
Ken




"Leonard Caillouet" wrote in message
...
Search for info on the PIP bypass for this set. You have leaky caps on

the
PIP module.

Leonard





  #6   Report Post  
Posted to sci.electronics.repair
No Name
 
Posts: n/a
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

================================================== =
Leonard -- You're The Man !!!!

I pulled the PIP, inserted the 2ea. [email protected] caps into the VF (GE) female
connector openings, cupped my marbles, closed my eyes, plugged in the
power cord, and Voila! A BRAND NEW TV !!!!

==================================================
"Leonard Caillouet" wrote in message
...
wrote in message
m...
Leonard, Thanks. You are dead on... "Search for info on the PIP bypass

for
this set. You have leaky caps on the PIP module".-- the caps WERE
leaking.
I used 91% isopropyl alcohol and a firm new 1" paint brush and cleaned

off
of the entire PIP (930B552). Then, I put the PIP on my car dashboard in
the
warm Sun for 2 hours before continuing. I made JPS's of every step I've
taken and am willing to send the pre-snot and post snot pics, and or all
other boards to anyone who requests analyzing them.

On the PIP, under the shield, I adjusted LO7102 & LO7101 (blk)

clockwise
to
where they stopped. I also flirted with VR7002 & VR7001 (blu) and

acquired
some improvement, but not much. Each time, I unplugged 110v, took the

PIP
board out, adjusted, reseated, replugged 100v., and re-powered on to

view.
Could I flirt with adjusting them while live?

What about rotational adjustments on the main board? Any advise?

Leonard, Here a current list of specs I've been able to match up:

brand ---------------------- Mitsubishi
model ---------------------- VS-45VA1
base manual ---------------- VS-45VA2
chassis---------------------- VZ1
year------------------------- 1992
service adjust code-option--- 008
service adjust code-video pip 007
convergence adjust code ---- 009
Line = 83MI
Item (OEM) Description
========== ==============
935D162002 Side PCC
935D157001 Display
935D156001 Control Board
935D155001 PreAmp
935D154001 Front Board
935D153001 FS
935D152002 Terminal Board
935C442002 PCC
935C441002 Signal Board
935C440001 CRT Assy.
935C439001 Power Sub
935C438002 Convergence Board
935C437002 Main Board
930B552001 PIP

I do not understand these terminologies or the implications "service
adjust
code option 008", "service adjust code video pip 007" , "convergence
adjust
code 009", and "Line = 83MI". I've spent the day scouring the net for

part
affiliation, and am looking for more insight.

Meat Plow, you say "You could always shotgun it by replacing the entire
video processing circuitry if you can determine where it is and find a
refurbed sub." Thanks Meat Plow, It's sounds like something I might
ultimately consider, but I'm not sure what "shotgun" and refurb "sub"
means
(power sub?) .

Thanks Franc. What is "AGC"? Automatic gain control ??? if it is what do

I
look for ? Is it replaceable, or is it possible to bypass also? Or

should
I
rule it out until the PIP issue is resolved?

Leonard, I may very well attempt a PIP bypass (if not replacemet). I

found
web documentation for a potential bypass at the main board PIP blue
connector "GE", pinout 5(+) to 11, and 7(+) to 9, 2 - 4.7 @ 50 volts.

HELP
on this!!! What does " 2 - 4.7" mean??? ... The pic is located at
http://members.aol.com/philselectron...ages/pipby.jpg

Thanks for your guidance,
Ken




"Leonard Caillouet" wrote in message
...
Search for info on the PIP bypass for this set. You have leaky caps on

the
PIP module.

Leonard




Just bypass the PIP module. Two caps and you are done.

Leonard





  #7   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

EXCESSIVE GREEN IN PICTU
Advice Sought

Back in the beginning of October, I cleaned
the TV's interior out (to like in new condition),
pulled the leaky PIP module and inserted the
2ea. [email protected] caps and was very happy to have
a functional TV.

My next step is to find guidance on getting the
prevailing "green" out of the picture.

I've I hit the reset button, and is does the
trick, however, the focus goes south, and
the contrast goes to the maximum level.
Color and bright go to the 50% level.
If I reduce the contrast, the picture
refocuses a-okay, but everything acquires
a green tint.

In another attempt after a reset, I left the
contrast alone, and reduced the "brightness"
to clear up the blury focus (no green tint).
It also does the trick, but I have to sit
away from the TV in the direct center, with
the lights off, to see the *dim* output with
excellent color and excellent focus.

Does anyone have Any suggestions I may
follow up on? Can I make an adjustment
on one of the boards, or do I need to replace
another cap or a different component?

Thank you for reading my post.
Ken

==========================================
brand ---------------------- Mitsubishi
model ---------------------- VS-45VA1
base manual ---------------- VS-45VA2
chassis---------------------- VZ1
year------------------------- 1992
service adjust code-option--- 008
service adjust code-video pip 007
convergence adjust code ---- 009
Line 83MI

Item (OEM) Description
========== ==============
935D162002 Side PCC
935D157001 Display
935D156001 Control Board
935D155001 PreAmp
935D154001 Front Board
935D153001 FS
935D152002 Terminal Board
935C442002 PCC
935C441002 Signal Board
935C440001 CRT Assy.
935C439001 Power Sub
935C438002 Convergence Board
935C437002 Main Board
930B552001 PIP
=========================================

  #8   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 3,833
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

Assuming that working through the usual adjustments (screen, drive, etc)
doesn't clear up the problem, it's likely you have a worn-out CRT with
insufficient red and blue output to match the green at "normal" brightness
levels.


  #9   Report Post  
Posted to sci.electronics.repair
No Name
 
Posts: n/a
Default MITSUBISHI VS-45VA1 - Rear_Projection TV

Hi William,

Thank you for replying.

However, I do not understand how a Cathode Ray Tube has anything to do with
my projection TV??

If you could elaborate, I'd appreciate it..

Thanks,

Ken





"William Sommerwerck" wrote in message
...

Assuming that working through the usual adjustments (screen, drive, etc)


doesn't clear up the problem, it's likely you have a worn-out CRT with


insufficient red and blue output to match the green at "normal" brightness


levels.






"William Sommerwerck" wrote in message
...
Assuming that working through the usual adjustments (screen, drive, etc)
doesn't clear up the problem, it's likely you have a worn-out CRT with
insufficient red and blue output to match the green at "normal" brightness
levels.





Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
TV repair help guidance sought on a Mitsubishi VS-45VA1 No Name Electronics 7 January 2nd 09 05:44 PM
TV repair help guidance sought on a Mitsubishi VS-45VA1 No Name Electronics Repair 12 January 2nd 09 05:44 PM
MITSUBISHI VS-45VA1 - Rear_Projection TV No Name Electronics 0 October 12th 08 12:06 AM
Mitsubishi TX-21 Gerald Spindler Electronics Repair 0 October 10th 04 09:46 AM
Mitsubishi TV has a bad cap or two..... Chris F. Electronics Repair 10 August 31st 04 10:29 PM


All times are GMT +1. The time now is 06:43 PM.

Powered by vBulletin® Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright 2004-2023 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"