Mitsubishi TV dead, component id required

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

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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

Reply to
jon
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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

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Reply to
Tech Data

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.

Reply to
jon

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

Reply to
Meat Plow

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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.

Reply to
jon

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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.

Reply to
Meat Plow

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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.

Reply to
James Sweet

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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.

Reply to
jon

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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?

Reply to
jon

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No need to apologize.

You had a response from another poster that provided a pretty decent educated guess as to what the function of that resistor is.

Pretty much hit or miss unless you've had experience or have lots of patience and spare time and are willing to learn. I've done plenty of repairs without a schematic. But you do need to be able to identify the general topography of what you are working on.

Reply to
Meat Plow

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.

Reply to
Jeroni Paul

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.

Reply to
James Sweet

On Wed, 10 Oct 2007 11:36:11 GMT, snipped-for-privacy@ghost.net put finger to keyboard and composed:

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

See

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- Franc Zabkar

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

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.

Reply to
James Sweet

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

Reply to
jon

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