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Sanyo DP46840 LCD Flatscreen Inop

March 3 2012 at 7:13 AM
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Lenny Haney  (Login ljhaney587)

 
Sanyo 46", Model DP46840, Manufactured: July 2010.

This post provides information in hopes it may help someone else.

A friend of a friend brought this set to me. It would not power up. It would attempt to come on and the power relay would click and the green power-on LED would light, but after a few seconds, the set would shut down & the relay would click off. Research on the Internet came up empty. Lots of people had this same problem, but no one posted a fix.

My usual troubleshooting failed to find the cause of why the set was going into shut down mode. Was able to find a service manual online for $15 and the owner bought it for me.

I found a missing +13vdc power source in the audio amplifier section. There is a switching regulator there that takes in +24vdc and outputs +13vdc. This regulator (IC1670) and the audio amplifier (IC001) are tiny surface mount devices. I wasn't sure if the regulator was bad....or if the audio amplifier was bad and loading down the regulator. I had to cut the tiny printed circuit board copper trace to isolate the 2 circuits.

That determined that the regulator (IC1670 p/n QXXGA0500165P or LV5806MX-TLM-H) was bad since it had +24v input and 0v output. Well, I could not locate that IC chip anywhere...Nobody sells it.

I could buy a whole new Main circuit board (1LG4B10Y04600_B) for $150 to fix this $600 set, but I wanted to fix it cheap.

So...I substituted in a standard linear regulator from my junk box that I had on hand: LM7815 (+15vdc regulator). I mounted it onto a heatsink, then mounted that onto a plastic crossmember and wired it into the circuit. Yes....I had to isolate the old regulator by cutting some more traces.

Set works great, the regulator only gets warm. I ran it for 10 hours for a burn-in test at a fairly high volume level.

Note: Circuitry is also applicable to the 42" Sanyo, model DP42840.

Best!


Lenny

 
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AuthorReply
Andy
(Login Restorer79)

Nice Repair

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March 19 2012, 11:23 AM 

Hi Lenny: That's a nice workaround, with the cost of parts for a lot of sets nowadays it looks like were going to have to do this sort of thing more & more to complete repairs at an affordable price.


Andy

 
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Dan_DBS
(Login Dan_DBS)

Sanyo IC1670 Fix

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July 26 2012, 8:45 AM 

lenny, how did the LM7815 work out? Did you send it home? I have 6 of these in the shop and I am very interested in your workaround. Like to send them back to the customers. TIA for information. Dan@DBS

 
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dreek
(Login dreek93sr20)

Sanyo dp42840

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June 8 2014, 12:52 PM 

Wassup guys I have a Sanyo dp42840 and the picture is solarized for some reason. In the past I replaced a capacitor on the main board because I had no picture. Now about a year after that the picture is solarized/negative look. Any ideas or fixes? I don't see any capacitors blown. Maybe new tcon board/main board?

 
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