Sharp LC-32D43U Dead

[budm]

Re: Sharp LC-32D43U Dead

Yes it is the snubber diode D7907 as indicated in post 1 (In mean time I noticed D7907 was shorted, it's the large diode next to the small transformer T7901.), he just had the typo.

[hapollo]

Re: Sharp LC-32D43U Dead

OK, it is the 142V 5W Zener diode for the snubber circuit, so right now more likely that you now also have damaged MOSFET which is why it blew the fusible resistor. We need to see more closed up pictures on the bottom and the top side to see where that MOSFET is, and hopefully it did not take out the SMPS IC with it.

Recently picked up a Sharp LC-42D62U which has same no power issue. Suspect it's a diode issue as well but diode in that area is a larger size. Need to figure out the diode rating and order from digikey.

Budm, How did you know the rating of the diode in the beginning of the post from just the picture?

A LC-42D62U I picked up seems so have the same issue but the diode seems larger and this other post mentions a similar issue that was resolved with a new diode but Wizard hasn't posted in the forums since 2011 so I'm not sure the rating of the diode.

https://www.badcaps.net/forum/showthread.php?t=8525

Thanks.

[daneshfar]

Re: Sharp LC-32D43U Dead

Someone please help me. I can see D7907 is bad when I test it but so is D7904. WHAT diode is that so I can change it as well.

[jetadm123]

Re: Sharp LC-32D43U Dead

Diode should be removed from board and checked again to verify it's bad. If bad, the diode should have the part number stamped on it.

[budm]

Re: Sharp LC-32D43U Dead

Budm, How did you know the rating of the diode in the beginning of the post from just the picture?

A LC-42D62U I picked up seems so have the same issue but the diode seems larger and this other post mentions a similar issue that was resolved with a new diode but Wizard hasn't posted in the forums since 2011 so I'm not sure the rating of the diode.

https://www.badcaps.net/forum/showthread.php?t=8525

Thanks.

It is 1N5383B
https://cdn.badcaps-static.com/pdfs/...82d096d57b.pdf
POST 5:
Yes it seems it is connected to anode of D7904 directly to left, showing very low ohms between the 2.
Whats printed on the diode is:

PK
IN
5383B
0842 or OS42

[hapollo]

Re: Sharp LC-32D43U Dead

A year later, decided to revisit this one sitting in the closet. Can the equivalent snubber diode be identified from this PSU in the LC-42D62U which has exact same issue as the LC-32D43U.

It think it might be D5075 in the middle bottom to the right of the transformer.

[budm]

Re: Sharp LC-32D43U Dead

It is an old thread, so which diode are we talking about, d???

[hapollo]

Re: Sharp LC-32D43U Dead

It is an old thread, so which diode are we talking about, d???

A year later, decided to revisit this one sitting in the closet. Can the equivalent snubber diode be identified from this PSU in the LC-42D62U which has exact same issue as the LC-32D43U.

It think it might be D5075 in the middle bottom to the right of the transformer.

As stated, D5705 in the middle bottom... actually left of the transformer, where it says 125V 7A I think.....

[budm]

Re: Sharp LC-32D43U Dead

That diode is in the cold side of the transformer.
I need the pictures of the bottom side of the board to verify.

[budm]

Re: Sharp LC-32D43U Dead

Is this the board?
Sharp RDENCA192WJQZ (LC606-4001AC) Power Supply for LC-42D62U
http://www.shopjimmy.com/sharp-rdenc...er-supply.htm#

Pictures provided by shopjimmy.
D5705 is the rectifier diode.

[hapollo]

Re: Sharp LC-32D43U Dead

based on another thread I found on some other forum for the 32" model which uses the same PSU, it seems like it would be 31DQ04-ND

Based on the discussion on this forum thread.

http://forum.allaboutcircuits.com/th...estion.100212/

[budm]

Re: Sharp LC-32D43U Dead

It is not the snubber diode.
Did it test out as shorted?

[budm]

Re: Sharp LC-32D43U Dead

D5701 is the snubber diode which is in the primary side, it is part of RCD SNUBBER NETWORK.

[hapollo]

Re: Sharp LC-32D43U Dead

Is this the board?
Sharp RDENCA192WJQZ (LC606-4001AC) Power Supply for LC-42D62U
http://www.shopjimmy.com/sharp-rdenc...er-supply.htm#

Pictures provided by shopjimmy.
D5705 is the rectifier diode.

I think so, TV is at a friend's summer home. Hence, the once a year visit and resurrecting an old thread to help them from tossing an old TV. The only other PSU on SJ is this one and I don't think there is a similar diode except maybe D5707 located on the left side by the Zebra label here:

http://assets.shopjimmy.com/media/ca...84wjqz-top.jpg

http://assets.shopjimmy.com/media/ca...jqz-bottom.jpg

Don't have test equipment there but just going by internet searching since I've found typically these LCDs fail in similar fashion. Almost like design defects.