I have a Hitachi CT4532 45" projection TV, and getting the following
behavior. When the TV is turned on from cold it usually starts
squeezing the picture in from the top and bottom within a few minutes.
It will then shrink a little more then the picture will disappear then
it has to be turned off for 15 mins or so (it varies) before you can
try again. BUT sometimes it will work without trouble and will work
100% until it is turned off again. And it worked for more then a week
without trouble until it was turned off. AND if the picture is
squeezing in a little bit (1-2" from the top and bottom) I can usually
change channels until the squeezing stops and then it will work fine
until turned off again. When changing the channels it does not slowly
disappear it will all of a sudden be working. A note that may help, the
horizontal output transistor has been replaced twice in the past but
this problem did not exist at those times. It came around about 2
months after it was replaced the second time. I don't have the
equipment to test the fly back .... Could it be anything else? Its way
to big to take somewhere and I cannot afford a tech right now as I'm
going to be going back to school for a MSc. Please help ..
- Eric

Sounds like dry solder joints in the Vertical
Deflection section.Remove the chassis and
inspect the area around the Vertical Out IC.
Resolder all in that area ,whilst in there ESR the
filter caps in the Vert Section.


kip
"Charon" wrote in message
oups.com...
I have a Hitachi CT4532 45" projection TV, and getting the following
behavior. When the TV is turned on from cold it usually starts
squeezing the picture in from the top and bottom within a few minutes.
It will then shrink a little more then the picture will disappear then
it has to be turned off for 15 mins or so (it varies) before you can
try again. BUT sometimes it will work without trouble and will work
100% until it is turned off again. And it worked for more then a week
without trouble until it was turned off. AND if the picture is
squeezing in a little bit (1-2" from the top and bottom) I can usually
change channels until the squeezing stops and then it will work fine
until turned off again. When changing the channels it does not slowly
disappear it will all of a sudden be working. A note that may help, the
horizontal output transistor has been replaced twice in the past but
this problem did not exist at those times. It came around about 2
months after it was replaced the second time. I don't have the
equipment to test the fly back .... Could it be anything else? Its way
to big to take somewhere and I cannot afford a tech right now as I'm
going to be going back to school for a MSc. Please help ..
- Eric

Agreed. If the top and bottom are closing in you have a vertical deflection
problem.

Check this tip:

---------------------------------------------------------------
Text pasted from WinSTIPS 2.0
http://www.ServiceSoftware.com
---------------------------------------------------------------

HITACHI CT4532

Vertical Def Shrunk

A1 Tv John

Resolder Stand Up Brd On Power/Def Board. .Board Is Located Almost In
Center. There are Three Little Transisters On The Board , They break Loose.
---------------------------------------------------------------



--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

========================

"kip" wrote in message
.. .
Sounds like dry solder joints in the Vertical
Deflection section.Remove the chassis and
inspect the area around the Vertical Out IC.
Resolder all in that area ,whilst in there ESR the
filter caps in the Vert Section.


kip
"Charon" wrote in message
oups.com...
I have a Hitachi CT4532 45" projection TV, and getting the following
behavior. When the TV is turned on from cold it usually starts
squeezing the picture in from the top and bottom within a few minutes.
It will then shrink a little more then the picture will disappear then
it has to be turned off for 15 mins or so (it varies) before you can
try again. BUT sometimes it will work without trouble and will work
100% until it is turned off again. And it worked for more then a week
without trouble until it was turned off. AND if the picture is
squeezing in a little bit (1-2" from the top and bottom) I can usually
change channels until the squeezing stops and then it will work fine
until turned off again. When changing the channels it does not slowly
disappear it will all of a sudden be working. A note that may help, the
horizontal output transistor has been replaced twice in the past but
this problem did not exist at those times. It came around about 2
months after it was replaced the second time. I don't have the
equipment to test the fly back .... Could it be anything else? Its way
to big to take somewhere and I cannot afford a tech right now as I'm
going to be going back to school for a MSc. Please help ..
- Eric

I tried resoldering the transistors on that board.
The three transistors only have two of the pins soldered. And the
middle pin is snipped off on all three. I think the one that is cut is
the collector.
I really hope that did the trick otherwise im not too sure where to go
next.
I will know soon.
How do I find the vertical out IC ?

The main board in the tv will be a pain to get out. Many wires soldered
onto it.


- Eric

read past posts
"Charon" wrote in message
ups.com...
I tried resoldering the transistors on that board.
The three transistors only have two of the pins soldered. And the
middle pin is snipped off on all three. I think the one that is cut is
the collector.
I really hope that did the trick otherwise im not too sure where to go
next.
I will know soon.
How do I find the vertical out IC ?

The main board in the tv will be a pain to get out. Many wires soldered
onto it.


- Eric

Well, the original soldering of the transistors, I did a poor job. And
I did not manage to fix it. So I went back in and did a much better job
of it and since then I have not seen the problem of the top and bottom
squeezing in. Looks like the problem is fixed. If not Ill just move on
and resolder other items linked to the vertial output.
Thanks a bunch guys. As I think the cost to fix the TV would have been
more then its worth.