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.

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Default Toshiba 42H81 convergence problem

Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

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Default Toshiba 42H81 convergence problem

On Wed, 14 Jun 2006 06:24:14 GMT, wrote:

Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

I forgot to mention that the blue is slightly out of focus and the
focus control works, but it won't adjust to a sharp focus like the red
and green.
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Tech Data
 
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Default Toshiba 42H81 convergence problem


wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J


There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

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Default Toshiba 42H81 convergence problem

On 13 Jun 2006 23:36:03 -0700, "Tech Data" wrote:


wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J


There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

You are probably right.
I forgot to mention that I did a self diagnostic test with these
results

SET ID : FF instead of SET ID : 01
EEP VER : FF instead of EEP VER : 02

I have the service manual and schematics already. But thanks for the
offer.
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Tech Data
 
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Default Toshiba 42H81 convergence problem


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J


There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net


Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net



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Default Toshiba 42H81 convergence problem

On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J


There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net


Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net

I'll have to ask him if the picture was good before the convergence
went bad.
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ampdoc
 
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Default Toshiba 42H81 convergence problem


wrote in message
...
On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net


Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net

I'll have to ask him if the picture was good before the convergence
went bad.


This model seems familliar. Is this the one with the STK's on the small
signal board, left side facing in from the rear? If so, look underneath the
heatsinks and see if there are 2 surface mount IC's there. I've seen the
logic ic's fail and cause this condition, if it is the chassis I'm thinking
about. I could be wrong though.

Before 100% giving up on the blue CRT try the optical focus first :-) they
have been known to defocus blue to help with the appearance of good color
balance if the blue emission is a bit weak :-)

Jammy


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Default Toshiba 42H81 convergence problem

On Wed, 14 Jun 2006 10:04:58 -0500, "ampdoc"
wrote:


wrote in message
.. .
On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU for
104.00 from Andrews. If you don't have the manual, I can fire it off to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net

I'll have to ask him if the picture was good before the convergence
went bad.


This model seems familliar. Is this the one with the STK's on the small
signal board, left side facing in from the rear? If so, look underneath the
heatsinks and see if there are 2 surface mount IC's there. I've seen the
logic ic's fail and cause this condition, if it is the chassis I'm thinking
about. I could be wrong though.

Before 100% giving up on the blue CRT try the optical focus first :-) they
have been known to defocus blue to help with the appearance of good color
balance if the blue emission is a bit weak :-)

Jammy

I just had a look at the bottom of the board and there aren't any
surface mount IC's on the bottom, just a few surface mount
transistors. On the component side of the board there are 3 SMIC's
74HC14a,74HC123A and JLC1562B.
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ampdoc
 
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Default Toshiba 42H81 convergence problem


wrote in message
...
On Wed, 14 Jun 2006 10:04:58 -0500, "ampdoc"
wrote:


wrote in message
. ..
On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU
for
104.00 from Andrews. If you don't have the manual, I can fire it off
to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net
I'll have to ask him if the picture was good before the convergence
went bad.


This model seems familliar. Is this the one with the STK's on the small
signal board, left side facing in from the rear? If so, look underneath
the
heatsinks and see if there are 2 surface mount IC's there. I've seen the
logic ic's fail and cause this condition, if it is the chassis I'm
thinking
about. I could be wrong though.

Before 100% giving up on the blue CRT try the optical focus first :-)
they
have been known to defocus blue to help with the appearance of good color
balance if the blue emission is a bit weak :-)

Jammy

I just had a look at the bottom of the board and there aren't any
surface mount IC's on the bottom, just a few surface mount
transistors. On the component side of the board there are 3 SMIC's
74HC14a,74HC123A and JLC1562B.


JLC1562B is the one I had to replace. You may still have a bad DAC though.

Jammy


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ampdoc
 
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Default Toshiba 42H81 convergence problem


wrote in message
...
On Wed, 14 Jun 2006 10:04:58 -0500, "ampdoc"
wrote:


wrote in message
. ..
On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU
for
104.00 from Andrews. If you don't have the manual, I can fire it off
to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net
I'll have to ask him if the picture was good before the convergence
went bad.


This model seems familliar. Is this the one with the STK's on the small
signal board, left side facing in from the rear? If so, look underneath
the
heatsinks and see if there are 2 surface mount IC's there. I've seen the
logic ic's fail and cause this condition, if it is the chassis I'm
thinking
about. I could be wrong though.

Before 100% giving up on the blue CRT try the optical focus first :-)
they
have been known to defocus blue to help with the appearance of good color
balance if the blue emission is a bit weak :-)

Jammy

I just had a look at the bottom of the board and there aren't any
surface mount IC's on the bottom, just a few surface mount
transistors. On the component side of the board there are 3 SMIC's
74HC14a,74HC123A and JLC1562B.


I forgot to mention that there are some jumpers for the power supplies to
the STK's near the heatsinks, and also some ground jumpers, I found on one
of the sets bad solder on the ground connections, the joints looked good to
the naked eye, but were noticeably bad under a magnifier. The faulty ground
also damaged the JLC1562B.

Jammy




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Default Toshiba 42H81 convergence problem

There is no way all the STKs failed at once. Ask the customer how long
the set was running when this happened. If it was a very short time you
might just need caps in the DCM (DCU). Problem is the data are
scrambled now. In other words the reset routine didn't work right.

I wouldn't be afraid to try a blank EPROM in it before ordering the
DCM. Thing is, you better be good at convergence.

We got one of these sitting at the shop, and the crosshatch pattern is
like art, it really is. It came in with dead STKs but after replacing
them we know the DCM drove them to death.

Anyway, a new DCM will require full alignment so an EPROM might be the
way to go. Actually if you could just find a way to erase the EPROM in
there now you might be alright.

If you can adjust any of the convergence, see if it actually adjusts
the point where the cursor is, if not, screw it, get a DCM. If it
adjusts the wrong place on the screen the processor is probably
screwed, and having a major change when you change the EPROM doesn't
indicate anything else.

Actually I succeeded once in aligning one that adjusted the wrong
points on the screen and it never came back.

Let's put it this way, the DACs are seperate so all of them did not
fail at the same time, the main processor(s) and the EPROM are what are
common to all colors.

If, and it's a big if, you can align it, just check all the lytics and
realign it. Problem is you might not be able to align it. If you can at
that point it'll probably nevrer happen again.

Actually $107 isn't all that bad, if it's high definition, wait until
the scan convertor (hyper module) goes !

Don't worry about the blue focus, for one it doesn't have to focused
all that tight, and in some sets needs to be defocused to achieve color
temperature. Of course the optical focus is set dead nuts, but there is
an offset for the electrical focus. Going slowly through the range of
the electrical focus, the blue should darken a bit. This is perfect
focus and that is when you do the optical focus. Then you again offset
the electrical focus. This only applies to blue on tri-CRT projection
TVs.

JURB

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Default Toshiba 42H81 convergence problem

On Wed, 14 Jun 2006 19:36:19 -0500, "ampdoc"
wrote:


wrote in message
.. .
On Wed, 14 Jun 2006 10:04:58 -0500, "ampdoc"
wrote:


wrote in message
...
On 14 Jun 2006 00:07:12 -0700, "Tech Data" wrote:


Tech Data wrote:
wrote:
Customer says he was going to change from vcr to tv after watching a
movie but hit the power button instead of the change antenna input
source. He pushed the power button again and the tv looked like this
http://users.eastlink.ca/~rayj/images/toshiba.jpg
(this is a crosshatch pattern I put on the tv)

No fuses blown.
I checked the +32V -32V +16V -16V all good
checked the low ohm resistors behind the stk's and all were good
I changed the two stk-392-110 with stk392-110 with no improvement.
So i figure I might have got some bad stk392-110 and put in two
stk392-120 with no improvement.

Any ideas are appreciated
thanks
Ray J

There's no soft way to say it but, the DCU is screwed. The same exact
thing happened to me a couple of months ago on the 50" flavor of that
series. I had just done the entire convergence alignment and did a
minor tweak in the service menu. The manual states when done, to exit
service mode power off then back on. Did that and, mine looked worse
than yours and there was nothing I could do but order the whole DCU
for
104.00 from Andrews. If you don't have the manual, I can fire it off
to
you or at the least, the part number for it. Cheaper, I know to order
the eeprom for that circuit but, if you're not Toshiba ASC all you'll
get is a blank one. You'll still have to be ASC to have them program
it. Also, make sure you order the circuit for that exact model. Mine
just took a minor touchup and it was done. Lemme know if you need
anything on that set.

Santy
www.techdata-kicksass.net

Sorry, fogot the blue tube issue. I think you have two problems you're
fighting and, a bad blue tube wouldn't be out of line to suggest. You
could swap the screen/focus leads on the block with another tube to see
but, if it adjusts like you say, my money's on the tube. Make sure you
throw that possiblity out to the customer before investing big money on
parts. Good luck.

Santy
www.techdata-kicksass.net
I'll have to ask him if the picture was good before the convergence
went bad.

This model seems familliar. Is this the one with the STK's on the small
signal board, left side facing in from the rear? If so, look underneath
the
heatsinks and see if there are 2 surface mount IC's there. I've seen the
logic ic's fail and cause this condition, if it is the chassis I'm
thinking
about. I could be wrong though.

Before 100% giving up on the blue CRT try the optical focus first :-)
they
have been known to defocus blue to help with the appearance of good color
balance if the blue emission is a bit weak :-)

Jammy

I just had a look at the bottom of the board and there aren't any
surface mount IC's on the bottom, just a few surface mount
transistors. On the component side of the board there are 3 SMIC's
74HC14a,74HC123A and JLC1562B.


I forgot to mention that there are some jumpers for the power supplies to
the STK's near the heatsinks, and also some ground jumpers, I found on one
of the sets bad solder on the ground connections, the joints looked good to
the naked eye, but were noticeably bad under a magnifier. The faulty ground
also damaged the JLC1562B.

Jammy

I just checked for bad connections around the STK'S and allwere good
Thanks
Ray J
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Default Toshiba 42H81 convergence problem

On 14 Jun 2006 17:43:31 -0700, wrote:

There is no way all the STKs failed at once. Ask the customer how long
the set was running when this happened. If it was a very short time you
might just need caps in the DCM (DCU). Problem is the data are
scrambled now. In other words the reset routine didn't work right.

The customer said that he was watching a movie on his vcr and then was
going to watch TV. When he was switching from antenna 1 to antenna 2
he hit the power button by mistake then immediately hit the power
again to turn it back on. So I would guess that it was on for at least
an hour.

I wouldn't be afraid to try a blank EPROM in it before ordering the
DCM. Thing is, you better be good at convergence.

We got one of these sitting at the shop, and the crosshatch pattern is
like art, it really is. It came in with dead STKs but after replacing
them we know the DCM drove them to death.

Anyway, a new DCM will require full alignment so an EPROM might be the
way to go. Actually if you could just find a way to erase the EPROM in
there now you might be alright.

I think I'll try a new EEPROM and see what happens. If a new one makes
a difference then problem solved, if not I'll put the old one back in.

If you can adjust any of the convergence, see if it actually adjusts
the point where the cursor is, if not, screw it, get a DCM. If it
adjusts the wrong place on the screen the processor is probably
screwed, and having a major change when you change the EPROM doesn't
indicate anything else.

Actually I succeeded once in aligning one that adjusted the wrong
points on the screen and it never came back.

Let's put it this way, the DACs are seperate so all of them did not
fail at the same time, the main processor(s) and the EPROM are what are
common to all colors.

If, and it's a big if, you can align it, just check all the lytics and
realign it. Problem is you might not be able to align it. If you can at
that point it'll probably nevrer happen again.

Actually $107 isn't all that bad, if it's high definition, wait until
the scan convertor (hyper module) goes !

Don't worry about the blue focus, for one it doesn't have to focused
all that tight, and in some sets needs to be defocused to achieve color
temperature. Of course the optical focus is set dead nuts, but there is
an offset for the electrical focus. Going slowly through the range of
the electrical focus, the blue should darken a bit. This is perfect
focus and that is when you do the optical focus. Then you again offset
the electrical focus. This only applies to blue on tri-CRT projection
TVs.

JURB

With the self diagnostic check saying the SET ID is FF instead of 01
and the EEP VERSION as FF instead of 02, I am leaning towards a bad
EEPROM
Thanks
Ray J
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Tech Data
 
Posts: n/a
Default Toshiba 42H81 convergence problem


wrote:
On 14 Jun 2006 17:43:31 -0700,
wrote:

There is no way all the STKs failed at once. Ask the customer how long
the set was running when this happened. If it was a very short time you
might just need caps in the DCM (DCU). Problem is the data are
scrambled now. In other words the reset routine didn't work right.

The customer said that he was watching a movie on his vcr and then was
going to watch TV. When he was switching from antenna 1 to antenna 2
he hit the power button by mistake then immediately hit the power
again to turn it back on. So I would guess that it was on for at least
an hour.

I wouldn't be afraid to try a blank EPROM in it before ordering the
DCM. Thing is, you better be good at convergence.

We got one of these sitting at the shop, and the crosshatch pattern is
like art, it really is. It came in with dead STKs but after replacing
them we know the DCM drove them to death.

Anyway, a new DCM will require full alignment so an EPROM might be the
way to go. Actually if you could just find a way to erase the EPROM in
there now you might be alright.

I think I'll try a new EEPROM and see what happens. If a new one makes
a difference then problem solved, if not I'll put the old one back in.

If you can adjust any of the convergence, see if it actually adjusts
the point where the cursor is, if not, screw it, get a DCM. If it
adjusts the wrong place on the screen the processor is probably
screwed, and having a major change when you change the EPROM doesn't
indicate anything else.

Actually I succeeded once in aligning one that adjusted the wrong
points on the screen and it never came back.

Let's put it this way, the DACs are seperate so all of them did not
fail at the same time, the main processor(s) and the EPROM are what are
common to all colors.

If, and it's a big if, you can align it, just check all the lytics and
realign it. Problem is you might not be able to align it. If you can at
that point it'll probably nevrer happen again.

Actually $107 isn't all that bad, if it's high definition, wait until
the scan convertor (hyper module) goes !

Don't worry about the blue focus, for one it doesn't have to focused
all that tight, and in some sets needs to be defocused to achieve color
temperature. Of course the optical focus is set dead nuts, but there is
an offset for the electrical focus. Going slowly through the range of
the electrical focus, the blue should darken a bit. This is perfect
focus and that is when you do the optical focus. Then you again offset
the electrical focus. This only applies to blue on tri-CRT projection
TVs.

JURB

With the self diagnostic check saying the SET ID is FF instead of 01
and the EEP VERSION as FF instead of 02, I am leaning towards a bad
EEPROM
Thanks
Ray J


Seeing what can happen first hand, if you install a blank eeprom in the
DCU, make sure you have a fresh set of STK's and two 5 amp picos on
hand. Good luck.

www.techdata-kicksass.net

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