Greetings,

Went out to look at a Hitachi Projection TV, Convergence was way out,
thought I would pull the chassis and bring it back to the shop for
Convergence module and resistor replacement. Well, I forgot to get
the model # off the back, It is an AP53 Chassis. Someone repaired it
before, looks like all the low value current limit resistors were
replaced. Funny thing, Many are of different values, they have
obviously been replaced. Here goes,
RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 21 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm
none are open, I pulled all three STK4274's out and checked them with
my homemade huntron, all check the same, thought I might find at least
one with open output transistors looking back into the chip. All
three of these were replaced as well, could tell by the excessive
silicone transfer compound that was used. All of the diodes and caps
check out OK (with esr meter). I'd like to install the proper value
resistors for starters.
Does anyone have the values of these, or, perhaps a spot where I can
download the manual with the convergence/ alignment instructions?
This set is from my Dr. who did my heart surgery back in November,
would like to get it working for him.

Thanks in advance,

Markus

Model is ?????



"Markus" wrote in message
...
Greetings,

Went out to look at a Hitachi Projection TV, Convergence was way out,
thought I would pull the chassis and bring it back to the shop for
Convergence module and resistor replacement. Well, I forgot to get
the model # off the back, It is an AP53 Chassis. Someone repaired it
before, looks like all the low value current limit resistors were
replaced. Funny thing, Many are of different values, they have
obviously been replaced. Here goes,
RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 21 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm
none are open, I pulled all three STK4274's out and checked them with
my homemade huntron, all check the same, thought I might find at least
one with open output transistors looking back into the chip. All
three of these were replaced as well, could tell by the excessive
silicone transfer compound that was used. All of the diodes and caps
check out OK (with esr meter). I'd like to install the proper value
resistors for starters.
Does anyone have the values of these, or, perhaps a spot where I can
download the manual with the convergence/ alignment instructions?
This set is from my Dr. who did my heart surgery back in November,
would like to get it working for him.

Thanks in advance,

Markus

Kip,

Must of left the paper with the model # on it inside of the set..
Think that it was a 46UX20B or 21K, really can't remember, chassis is
definitely a AP53, It was manufactured August 1995. He is out of
town for a couple of weeks, learning how to use some sort of new CT
heart scanner.

Thanks for the reply,

Markus

On Sun, 26 Mar 2006 18:42:24 -0500, "kip" wrote:

Model is ?????



"Markus" wrote in message
.. .
Greetings,

Went out to look at a Hitachi Projection TV, Convergence was way out,
thought I would pull the chassis and bring it back to the shop for
Convergence module and resistor replacement. Well, I forgot to get
the model # off the back, It is an AP53 Chassis. Someone repaired it
before, looks like all the low value current limit resistors were
replaced. Funny thing, Many are of different values, they have
obviously been replaced. Here goes,
RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 21 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm
none are open, I pulled all three STK4274's out and checked them with
my homemade huntron, all check the same, thought I might find at least
one with open output transistors looking back into the chip. All
three of these were replaced as well, could tell by the excessive
silicone transfer compound that was used. All of the diodes and caps
check out OK (with esr meter). I'd like to install the proper value
resistors for starters.
Does anyone have the values of these, or, perhaps a spot where I can
download the manual with the convergence/ alignment instructions?
This set is from my Dr. who did my heart surgery back in November,
would like to get it working for him.

Thanks in advance,

Markus

RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 31 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm

These are correct values from the Schematic..

kip

Kip,

Thanks for checking, looked a little out of place. I ordered the stks
and will check the power supplies that feed them. I think I worked on
this same chassis a few years back. Think it had some sort of power
problem. Seen a few with the 'frosted up lens' problem. This one
looks pretty clean especially for its age.

Take care,

Markus

On Sun, 26 Mar 2006 22:25:30 -0500, "kip" wrote:


RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 31 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm

These are correct values from the Schematic..

kip

While the chassis is out just go over it with Mag
Glass for dry joints especially in the Conv Section.

kip

"Markus" wrote in message
news
Kip,

Thanks for checking, looked a little out of place. I ordered the stks
and will check the power supplies that feed them. I think I worked on
this same chassis a few years back. Think it had some sort of power
problem. Seen a few with the 'frosted up lens' problem. This one
looks pretty clean especially for its age.

Take care,

Markus

On Sun, 26 Mar 2006 22:25:30 -0500, "kip" wrote:


RK15, 16 are 5.6 Ohm
RK20, 21 are 4.7 Ohm
RK25, 26 are 8.2 Ohm
RK30, 31 are 6.8 Ohm
RK35, 36 are 6.8 Ohm
RK41, 42 are 4.7 Ohm

These are correct values from the Schematic..

kip

If you want the manual let me know I will send it to you.
Would need Model Number as well.
kip
"Markus" wrote in message
...
Kip,

Checked today, parts should be in tomorrow. I'll let you know how it
goes. I did some searching for a setup guide to get to the hidden
convergence screen, think that I found it, will let you know. I went
over the board with a magnifying glass, could find nothing out of the
norm. All diodes checked OK with my fluke meter, most of the time if
they are poor they will check high in the forward direction. Read
some ware that these PCB's break, funny thing is when I was removing
it the back got caught under the bolt in the center of the chassis
(lower cabinet anchor) I could see how that could happen. This board
doesn't look cracked. What bugs me is that the STK's checked OK
(statically) I did solder a couple funny looking joints, however, non
of those really looked open. I noticed there are LEDS for the various
power supply's. When I install it and fire it up I'll have to check
those. Just have a gut feeling that this sucker is going to be a
tuffy, wish I had the whole unit back in my shop. Thanks again for
checking those resistors. I dug around on the net, thought I could
find a manual for it, just found the alignment instructions.

Take care and have a great day,

Markus

Kip,

I called him yesterday after I got home, he was home, so, I took the
chassis back, hooked it up and fired it up, worked fine. I replaced
all three STK4274's and a couple funny look'n electrolytic caps. Plus
re soldered all of the cold joints. While I was there I spent some
time and cleaned up the optics, Looked great. Not very long ago I
worked on his main Proj TV, it is an AKAI, PT4293HD, it was totally
dead. Pulled that chassis, found the STK393-110's shorted and a hand
full of 3.9 ohm flameproof current limit resistors open. Took it back
and reassembled it. It worked fine, however, this set went out during
a storm. Must of powered down with loss of Horz drive without killing
the beam current. Has a line right up the middle on the red tube.
Funny thing, I did some checking, looks like it is a Samsung, the
circuit boards are G10 epoxy boards, mechanically a good design,
however, makes me wonder if getting a tube, or, set of tubes for it
would be worth it. I use to do all of our Campus Barco projectors, I
always hated flipping on the switch the first time with the tube beam
current enabled after doing a tube job. Do you think it would be
worth the repair? Do you have a source for replacement jugs for these
beasts? I know that sending the jugs out for rebuild is out of the
question being the phosphor is toasted. Checking on the net it looks
like this is a bummer model, ever seen one of these Akai PT4293HD 's?

Thanks again for the help,

Markus

.. On Wed, 29 Mar 2006 07:52:25 -0500, "kip"
wrote:

If you want the manual let me know I will send it to you.
Would need Model Number as well.
kip
"Markus" wrote in message
.. .
Kip,

Checked today, parts should be in tomorrow. I'll let you know how it
goes. I did some searching for a setup guide to get to the hidden
convergence screen, think that I found it, will let you know. I went
over the board with a magnifying glass, could find nothing out of the
norm. All diodes checked OK with my fluke meter, most of the time if
they are poor they will check high in the forward direction. Read
some ware that these PCB's break, funny thing is when I was removing
it the back got caught under the bolt in the center of the chassis
(lower cabinet anchor) I could see how that could happen. This board
doesn't look cracked. What bugs me is that the STK's checked OK
(statically) I did solder a couple funny looking joints, however, non
of those really looked open. I noticed there are LEDS for the various
power supply's. When I install it and fire it up I'll have to check
those. Just have a gut feeling that this sucker is going to be a
tuffy, wish I had the whole unit back in my shop. Thanks again for
checking those resistors. I dug around on the net, thought I could
find a manual for it, just found the alignment instructions.

Take care and have a great day,

Markus

Glad you are up and running...
Oh ont he projectors I ahve zero info as those I DTWABP.



kip
"Markus" wrote in message
...
Kip,

I called him yesterday after I got home, he was home, so, I took the
chassis back, hooked it up and fired it up, worked fine. I replaced
all three STK4274's and a couple funny look'n electrolytic caps. Plus
re soldered all of the cold joints. While I was there I spent some
time and cleaned up the optics, Looked great. Not very long ago I
worked on his main Proj TV, it is an AKAI, PT4293HD, it was totally
dead. Pulled that chassis, found the STK393-110's shorted and a hand
full of 3.9 ohm flameproof current limit resistors open. Took it back
and reassembled it. It worked fine, however, this set went out during
a storm. Must of powered down with loss of Horz drive without killing
the beam current. Has a line right up the middle on the red tube.
Funny thing, I did some checking, looks like it is a Samsung, the
circuit boards are G10 epoxy boards, mechanically a good design,
however, makes me wonder if getting a tube, or, set of tubes for it
would be worth it. I use to do all of our Campus Barco projectors, I
always hated flipping on the switch the first time with the tube beam
current enabled after doing a tube job. Do you think it would be
worth the repair? Do you have a source for replacement jugs for these
beasts? I know that sending the jugs out for rebuild is out of the
question being the phosphor is toasted. Checking on the net it looks
like this is a bummer model, ever seen one of these Akai PT4293HD 's?

Thanks again for the help,

Markus

. On Wed, 29 Mar 2006 07:52:25 -0500, "kip"
wrote:

If you want the manual let me know I will send it to you.
Would need Model Number as well.
kip
"Markus" wrote in message
. ..
Kip,

Checked today, parts should be in tomorrow. I'll let you know how it
goes. I did some searching for a setup guide to get to the hidden
convergence screen, think that I found it, will let you know. I went
over the board with a magnifying glass, could find nothing out of the
norm. All diodes checked OK with my fluke meter, most of the time if
they are poor they will check high in the forward direction. Read
some ware that these PCB's break, funny thing is when I was removing
it the back got caught under the bolt in the center of the chassis
(lower cabinet anchor) I could see how that could happen. This board
doesn't look cracked. What bugs me is that the STK's checked OK
(statically) I did solder a couple funny looking joints, however, non
of those really looked open. I noticed there are LEDS for the various
power supply's. When I install it and fire it up I'll have to check
those. Just have a gut feeling that this sucker is going to be a
tuffy, wish I had the whole unit back in my shop. Thanks again for
checking those resistors. I dug around on the net, thought I could
find a manual for it, just found the alignment instructions.

Take care and have a great day,

Markus