Emerson LC401EM2F

[rn74]

Hello. I have an Emerson 40" LCD TV that stopped working. I removed the back panel and noticed the 8A 250V fuse near the AC input was open. I'm pretty familiar with working on computers (replacing caps, power jacks, etc.) but I know little about TVs.

I can simply replace the fuse, but I'd rather check around and make sure everything is good before I put power to it again. All the caps look fine, no signs of damage visually.

I saw a Youtube video where someone had the same problem. He determined, without saying exactly how, it was on the AC side. Then he determined he had two bad diodes. Again, he didn't say how. Can someone walk me through what I should test?

Thanks!

[selldoor]

Re: Emerson LC401EM2F

Did anything accompany the not working? Bang Flash?

Was it subjected to any powersurge.

One way instead of testing all components is to rig a lightbulb in place of the fuse - see here
http://antiqueradio.org/dimbulb.htm


Dont think we fixed it but this will give you some ideas
https://www.badcaps.net/forum/showth...M2F#post250318

You will need to post pictures of YOUR boards.

[killian6pk]

Re: Emerson LC401EM2F

Hello and welcome. I tried to find a free service manual for your tv, but could not. This is a link to a site that sells the service manuals. Tom66 has a free site for manuals but could not find one there either. http://www.service-manual.net/ashop/...tpage=4&shop=1

You need to post pictures using the section under go advanced below the quick reply. Take one picture of back of tv after removing the back cover. Then one picture of the back and front of each of the power and main boards. Resolution no more that 2000 x 2000. We need to be able to read the printing on the boards. No flash just well lit.

[rn74]

Re: Emerson LC401EM2F

Thanks for the replies. I did check that link and that very diode appears to be faulty on mine as well. I found several others near that relay that are also bad. It may have been hit with a power surge. It was turned off and nobody was present, but there were storms in the area.

I'll post some pictures as soon as I'm able - likely first thing in the morning.



Looks like, per shopjimmy.com, that this model's power board is also used in:

MAGNAVOX 40MF401B/F7
PHILIPS / FUNAI CLC401EM2F
SYLVANIA LC401EM2
SYLVANIA LC401EM2F
SYLVANIA LC401SS2

So I've started looking for information on those as well, but no luck yet. Thanks again!

[killian6pk]

Re: Emerson LC401EM2F

Check tom's free site under each of those and see if there is a service manual. Most of the time they will have a flow chart that helps to run down problems.

http://www.tgohome.com/ServiceManuals

[rn74]

Re: Emerson LC401EM2F

Thanks. I tried them all and no joy.

[lilmonk3]

Re: Emerson LC401EM2F

Same model here and same problem... Blows the fuse as soon as its plugged in. Been busy with back to school stuff so I have not had time to mess with it.. But, I have unhooked all boards.. And one by one I hooked them back up..
Grey flat power cable going from PS to Main, fuse fine but no life on standby lights or power.Next was Flat white slip in ribbon cable going from PS to main
and thats when the fuse blows..Hopefully I can find time soon to get back to my TV stuff.

[lilmonk3]

Re: Emerson LC401EM2F

Ok I have some time to mess with this.. Here are a few results from some diodes that I have tested
D1215 Is reading large # s in both directions
D1401 " "
D1603 " "
D606 Reading 000 both directions

[retiredcaps]

Re: Emerson LC401EM2F

D606 Reading 000 both directions

Remove D606 and retest. I normally use diode test function on the multimeter.

[lilmonk3]

Re: Emerson LC401EM2F

Ok will do .. I have been using the diode setting..

[retiredcaps]

Re: Emerson LC401EM2F

Ok will do .. I have been using the diode setting..

Then report your readings all diodes. Your results in post#8 are vague. "large #s' mean nothing.

[lilmonk3]

Re: Emerson LC401EM2F

Readings in diode mode with D606 Removed
D606 OL .663
D1215 .027 .027
D1603 .125 .142
D1401 .665 other way Climbs to .980 then OL

[retiredcaps]

Re: Emerson LC401EM2F

Readings in diode mode with D606 Removed
D606 OL .663
D1215 .027 .027
D1603 .125 .142
D1401 .665 other way Climbs to .980 then OL

D1215 and D1603 are both shorted in circuit. Remove both and retest out of circuit.

D606 is good out of circuit. Leave it out of circuit for now.

[budm]

Re: Emerson LC401EM2F

D606 may be in parallel with something with low Ohm usch as inductor/transformer widing or very low Ohm resistor.

D1215 .027 .027
D1603 .125 .142
These two looks bad, are you measuring them in the circuits or they are removed?

[lilmonk3]

Re: Emerson LC401EM2F

D606 may be in parallel with something with low Ohm usch as inductor/transformer widing or very low Ohm resistor.

D1215 .027 .027
D1603 .125 .142
These two looks bad, are you measuring them in the circuits or they are removed?

Bud.. the only one out of circuit in those reading was d606

[budm]

Re: Emerson LC401EM2F

I always test them out off the board when they read bad/strange on the board, it just a way to verify for sure.

[lilmonk3]

Re: Emerson LC401EM2F

Ok all of the following out of circuit..
D606 OL .663
D1215 OL .547
D1603 OL .660
D1401 OL .653

[budm]

Re: Emerson LC401EM2F

At this point I will need really good clear pictures of the bottom side of the board to trace out the connections and see how these Diode are hooked up. They tested OK out off the board.

[lilmonk3]

Re: Emerson LC401EM2F

If those are not good enough, another member posted some pics here https://www.badcaps.net/forum/showth...M2F#post250318

Its cloudy here today and I have crappy lighting in my house

[budm]

Re: Emerson LC401EM2F

I rather use yours clear pictures since other board may not be the same revision, it is already hard enough try tracing the connections without having the board in front of me while toggling back and forth between the picture of the top of the board and bottom of the board to get correct part locations. I may ask for closed up later.
Can I get the picture of the top board that I can see the whole board, your earlier pictures cutout part of the board.