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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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05-02-2012, 05:10 AM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Hello, Well I tried reinserting any connectors. No luck on the black line.
Here are some photos of what it looks like.

Not the end of the world if it cant be fixed, Its not bad enough to make you not watch it.

It is almost completely gone in some scenes. It runs from the top to about 3/4 of the way down.

Read somewhere that it might be that two lcd screens were joined together and are now separating at the joint.

Thank you for any insight that you guys might have....

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Last edited by scatman0000; 05-02-2012, 05:12 AM.
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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-19-2012, 05:19 AM
Re: MAGNAVOX no picture powers LED 47MF437B/37

I will open it up tonight and try the connectors.

Thanx

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-18-2012, 07:28 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Success !!! Received new Diodes soldered them in and wham TV is working now.

One problem though, There is a Faint Black Line In the middle of the screen.

It is almost gone in bright scenes, Most visible during dark scenes.

Any input on that?

Thank you for helping with the power supply everyone!!!!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 08:02 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

I would like to thank you guys!!

I will wait until I get my new diodes installed and then go from there.

Thank you again!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 07:54 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

so hopefully after installing the new ZD diodes (ZD902, ZD904) it should work correct?

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 07:45 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Oops! ?

Sounds Bad

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 07:18 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Using the 200k Ohm selection on meter this is what I got.

Q901 - Pins 1 & 2 = Just infinite reading
Q901 - Pins 1 & 3 = Just infinite reading
Q901 - Pins 2 & 3 = Numbers rise then goes infinite

Could The "Q901" reading be that way because I do not have the ZD902 & ZD904 back in yet?

Q902 - Pins 1 & 2 + 2 &3 = Numbers rise then go infinite
Q902 - Pins 1 & 3 = 27.3

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 06:47 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

I haven't replaced the zd902 & zd904 yet. They should arrive here Tuesday or Wednesday.

Should I worry about the "Q901"?
Could it be damaged?...

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Last edited by scatman0000; 04-15-2012, 07:00 PM.
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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 06:36 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Sorry to be such a pain, It must be frustrating to have someone ask so many questions.

I really do appreciate all the help I am getting from everyone!!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 06:14 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

When I put it back in the board, I get "001" in both directions again.

I had already removed the Diodes in the burned area.

What could the problem be?

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-15-2012, 05:52 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Diode "D912" Test "584" in output side
Test "infinite" in other side.

That is taken out of the board.

Should I put that one back in?

Should I be worried about the test readings when it was in the board?

I will also look at getting the other capacitors. Might as well since I am doing all this.

Thank You !!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 09:46 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Thank you, I will do that tomorrow. Also should I be worrying about my transformer or is that thing bullet proof?

Thanx Again!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 09:31 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

The Diode in location "D925" measured "555" in one direction only, Infinite in the other.

The Diode in location "D907" measured "572" in one direction only, Infinite in the other.

The Diode in location "D912" measured "001" in both directions. Should I pull this one too and test it out of the board?

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 06:29 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Thank you, Will wait until I get my diodes installed and then will report back.

This Forum has so far proven to be very helpful.

Thank you to every one who replied.

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 04:39 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Thank you for your help, Would a automotive wire 18 to 22 gauge work?
They have insulation on them and I have plenty of that available to me.
The website for the diodes looks like a decent site, I will order from there.
Thanx Again

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 01:38 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Pulled the diodes Test Results Below.

Diode 1 show 18 in both directions

Diode 2 shows 779 Red probe on output side.
455 Black probe on output side.

Output side being the one with the stripe.

Also some of the pad came up on the burned area when removing these Diodes.
Can I use a paperclip or some wire to bridge the two together?

And are there any stores that would carry these diodes?
I browsed Radio Shack website and couldn't find...

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-14-2012, 06:36 AM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Thank you for the info, I will remove the diodes and report back. Thanks again!

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-13-2012, 06:44 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

I tested it with a multimeter on the diode setting and I get readings on both sides of the two diodes. I assume that means that they are bad . I am still learning and am unsure of some of my results. Will all properly working diodes give me a reading only in one direction when they are good? Both directions when bad? Thanx

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scatman0000 replied to MAGNAVOX no picture powers LED 47MF437B/37

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04-13-2012, 05:37 PM
Re: MAGNAVOX no picture powers LED 47MF437B/37

Hello, I am also a newbie to psu repair. I have the same power supply and it is doing the chirping and wont turn on. I had three capacitors that were blown "3 big ones together" I also have Black Spots on top and bottom of board where it looks burned. Can I assume that these are bad and that I might even need to bridge the under side of the board where they connect? Thank you for any help ...

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