I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen here
http://smg.photobucket.com/albums/v4...subishipsu.jpg

I don't know if I should be getting voltages at some points or whether
they are triggered by something else but here goes.

The connector circled in yellow is outputting 12v, the plug from this
one goes onto a strap at the rear of the screen.

The output circled in green has no reading, the cable from this one
goes into the main board.

The component circled in blue is I assume a resistor, but seems as
though it is o/c, this supplies the line up to the green circled
output.

Any advice would be much appreciated.

cheers

On Oct 9, 9:54 am, wrote:
I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen herehttp://smg.photobucket.com/albums/v412/jackboyo/?action=view¤t=...

I don't know if I should be getting voltages at some points or whether
they are triggered by something else but here goes.

The connector circled in yellow is outputting 12v, the plug from this
one goes onto a strap at the rear of the screen.

The output circled in green has no reading, the cable from this one
goes into the main board.

The component circled in blue is I assume a resistor, but seems as
though it is o/c, this supplies the line up to the green circled
output.

Any advice would be much appreciated.

cheers

Your problem isn't on this board. This is nothing more than the AC
input and the resistor is being used for surge, more like a 'second
fuse' and is most likely just fine. It has to be going to a DC
rectifier stage somewhere and the fact that you have 12 volts on the
return line means at least the standby stage is most likely working
fine. This looks kind of old so, not sure if it uses a switching power
supply or a series pass but, that's where your problem is and that's
as far as I can go since that model and chassis doesn't equate to a US
version.
tvdoc
http://tvtechdata.net

The TV is 9 years old and I know that it is probably not worth having
someone to repair it, but there was a cracking picture on it.
I was expecting some sort of switching supply on the board myself. The
resistor I mentioned seemed to be dubious as I checked continuity
across it and there is just nothing there, totally open circuit.

What I really need to get hold of is a scehmatic, but from where I
don't know.

So what you are saying is, the problem is probably on the main board?

BTW thanks for clearing up part of the circuit, will now just push on
from here.

Your problem isn't on this board. This is nothing more than the AC
input and the resistor is being used for surge, more like a 'second
fuse' and is most likely just fine. It has to be going to a DC
rectifier stage somewhere and the fact that you have 12 volts on the
return line means at least the standby stage is most likely working
fine. This looks kind of old so, not sure if it uses a switching power
supply or a series pass but, that's where your problem is and that's
as far as I can go since that model and chassis doesn't equate to a US
version.
tvdoc
http://tvtechdata.net

On Tue, 09 Oct 2007 12:50:57 -0400, Meat Plow
wrote:

On Tue, 09 Oct 2007 14:54:17 +0000, jon wrote:

I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen here
http://smg.photobucket.com/albums/v4...subishipsu.jpg

If you think that is the power supply board maybe you should defer the
repair to someone with a better understanding of your tv.

What a great reply, typical of one that i expected.

You obviously know nothing about it or are you just trying to be
clever. Try reading my last post for the reason that i am looking at
it.

wrote in message
...
I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen here
http://smg.photobucket.com/albums/v4...subishipsu.jpg

I don't know if I should be getting voltages at some points or whether
they are triggered by something else but here goes.

The connector circled in yellow is outputting 12v, the plug from this
one goes onto a strap at the rear of the screen.

The output circled in green has no reading, the cable from this one
goes into the main board.

The component circled in blue is I assume a resistor, but seems as
though it is o/c, this supplies the line up to the green circled
output.

Any advice would be much appreciated.

cheers

The thing in blue is a power resistor, the pic is a little fuzzy but it
looks like it says 470 or 4.70K, so it should read something close to one of
those values.

On Tue, 09 Oct 2007 17:07:58 -0400, Meat Plow
wrote:

On Tue, 09 Oct 2007 18:19:11 +0000, jon wrote:

On Tue, 09 Oct 2007 12:50:57 -0400, Meat Plow
wrote:

On Tue, 09 Oct 2007 14:54:17 +0000, jon wrote:

I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen here
http://smg.photobucket.com/albums/v4...subishipsu.jpg

If you think that is the power supply board maybe you should defer the
repair to someone with a better understanding of your tv.

What a great reply, typical of one that i expected.

You obviously know nothing about it or are you just trying to be clever.
Try reading my last post for the reason that i am looking at it.

The first tv I repaired had tubes in it. That was back when they had only
tubes. Worked on All major brands since then up until about 8 years ago.
Your absurd statement that I know nothing is just that, absurd. On the
other hand my statement comes from your misunderstanding of your tv's
components and was by no means meant to be inflammatory. As others have
mentioned your problem won't likely be found on the on/off switch board
unless there is a poor solder joint there. You should locate and look for
poor solder joints or caps with high ESR barring getting ahold of a
service manual and going through the voltages and applying you
troubleshooting skills.

I am sorry for that outburst as I did take it entirely in the wrong
context. I do apologise.

This was probably as far as i was originally going to go with this TV,
but I noticed that this resistor is open circuit and just trying to
get a reason for it.
I can understand that without a schematic I have no chance of
repairing it unless I got lucky.

On Wed, 10 Oct 2007 01:24:55 GMT, "James Sweet"
wrote:


wrote in message
.. .
I have a Mitsubishi CRT tv model no. C28D7B chassis EE6 which has
stopped working 2 days ago. When you hit the power button nothing
happens.
I've pulled out the power supply board to check for o/c and s/c and
have a few queries.
the board can be seen here
http://smg.photobucket.com/albums/v4...subishipsu.jpg

I don't know if I should be getting voltages at some points or whether
they are triggered by something else but here goes.

The connector circled in yellow is outputting 12v, the plug from this
one goes onto a strap at the rear of the screen.

The output circled in green has no reading, the cable from this one
goes into the main board.

The component circled in blue is I assume a resistor, but seems as
though it is o/c, this supplies the line up to the green circled
output.

Any advice would be much appreciated.

cheers

The thing in blue is a power resistor, the pic is a little fuzzy but it
looks like it says 470 or 4.70K, so it should read something close to one of
those values.

It says 10w 4.7k on it but when checking with a meter across both ends
it is open circuit. Obviously there should be a resistance or has it
gone faulty?
Or is there some other way that it works?

It says 10w 4.7k on it but when checking with a meter across both ends
it is open circuit. Obviously there should be a resistance or has it
gone faulty?
Or is there some other way that it works?

That resistor should read that value on the meter, otherwise it is
faulty, you might try to replace it and see if you are lucky.

This was probably as far as i was originally going to go with this TV,
but I noticed that this resistor is open circuit and just trying to
get a reason for it.
I can understand that without a schematic I have no chance of
repairing it unless I got lucky.


Sure you do, I've been fixing things as a hobby for over a decade, it's been
very rare for me to be lucky enough to have a schematic.

On Wed, 10 Oct 2007 11:36:11 GMT, put finger to keyboard
and composed:

On Wed, 10 Oct 2007 01:24:55 GMT, "James Sweet"
wrote:

The thing in blue is a power resistor, the pic is a little fuzzy but it
looks like it says 470 or 4.70K, so it should read something close to one of
those values.

It says 10w 4.7k on it but when checking with a meter across both ends
it is open circuit.

No, it says "4.7 ohms K", which means 4.7 ohms 10%.

See http://wiki.xtronics.com/index.php/Resistor_Codes

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

"Franc Zabkar" wrote in message
...
On Wed, 10 Oct 2007 11:36:11 GMT, put finger to keyboard
and composed:

On Wed, 10 Oct 2007 01:24:55 GMT, "James Sweet"
wrote:

The thing in blue is a power resistor, the pic is a little fuzzy but it
looks like it says 470 or 4.70K, so it should read something close to one
of
those values.

It says 10w 4.7k on it but when checking with a meter across both ends
it is open circuit.

No, it says "4.7 ohms K", which means 4.7 ohms 10%.

See http://wiki.xtronics.com/index.php/Resistor_Codes




I wonder why they would use K as part of the code, that's confusing.

At any rate 4.7 ohms should read nearly a short circuit, if it's open,
replace it.

On Fri, 12 Oct 2007 06:09:10 +1000, Franc Zabkar
wrote:

On Wed, 10 Oct 2007 11:36:11 GMT, put finger to keyboard
and composed:

On Wed, 10 Oct 2007 01:24:55 GMT, "James Sweet"
wrote:

The thing in blue is a power resistor, the pic is a little fuzzy but it
looks like it says 470 or 4.70K, so it should read something close to one of
those values.

It says 10w 4.7k on it but when checking with a meter across both ends
it is open circuit.

No, it says "4.7 ohms K", which means 4.7 ohms 10%.

See http://wiki.xtronics.com/index.php/Resistor_Codes

- Franc Zabkar
Well spotted, I just could not remember what the k stood for, long
time since I went down to component level.

Just checked it again and it is open circuit, so, will pick a new one
up and try it