Insignia NS L42Q 10A

[budm]

Re: Insignia NS L42Q 10A

According the closest spec for this panel, the in-rush current on the T-CON is 4Amps.
I would suggest 5A fuse. I myself use through hole fuse LITTLEFUSE PICOII series from Mouser or Digikey.

[alecjahn]

Re: Insignia NS L42Q 10A

You've been a huuuuuge help, budm. And everyone else, of course! Thank you all for all your time and efforts. I will order a fuse tonight and install it as soon as it arrives.

Do I need to pay attention to voltage and such? Slo or fast blow?

Ordering from digikey/mouser is always scary for me.

P.S. I just noticed your signature. I like to tell myself that from time to time.

[budm]

Re: Insignia NS L42Q 10A

This is what I use, through hole fuse. You just have to bend the legs:
http://www.digikey.com/product-detai...2317-ND/700749

Or you can get the surface mounted type but you have to measure the Height and the Width, see spec attached.
This one may fit but verify:
http://www.digikey.com/product-detai...2CT-ND/1948194
You just lay the new on on top and solder both ends to the old one.

Digikey does USPS shipping for light weight for $2.50
Please get more than one just in case there are other stages on the T-CON that is active shorted.

I fixed 37" Insignia that had shorted cap after the switching regulator.
http://s807.photobucket.com/albums/y...NS-LCD37HD-09/

[alecjahn]

Re: Insignia NS L42Q 10A

Thanks. I'll just go with the through-hole, I think.

I just remembered I will be on vacation from the 13th through the 17th... which means if it doesn't arrive before then, I won't be able to report back on its replacement until after then. Hopefully that won't be the case.

I would have checked the mom 'n pop record store today if I had remembered to... before they closed... and they aren't open on Saturday. But there's a decent chance they would have something like that. Oh well.

It'll get done eventually.

Thanks again.

[tom66]

Re: Insignia NS L42Q 10A

Bud - A little unrelated but in the Insignia 37" images you say 10uF 25V for the cap - how did you determine this? I had a 17" LCD with a shorted ceramic which I couldn't identify, so difficult to fix...

[budm]

Re: Insignia NS L42Q 10A

I find that out because they use like 8 of them in parallel, the bad thing was that I remove them one at a time until the short goes away, and guess what, it was the last one I removed!
The board runs on 12V so I pick the 25v rating.

[tom66]

Re: Insignia NS L42Q 10A

I find that out because they use like 8 of them in parallel, the bad thing was that I remove them one at a time until the short goes away, and guess what, it was the last one I removed!
The board runs on 12V so I pick the 25v rating.

Oh how I can relate to that. Pulled about 15x 100n's off a prototype board to find a short on the last one!! I guess you can assume 16V or 25V and find the highest capacitance for that size e.g. 1206. But no T-con schematics make it difficult. I think all manufacturers should be required to provide at least a basic schematic and service manual, but I guess they are too afraid of competition stealing the designs...

[alecjahn]

Re: Insignia NS L42Q 10A

Is there a reason to use multiple capacitors in parallel instead of less of them, even just one? Money? Reliability...?

[budm]

Re: Insignia NS L42Q 10A

They need low profile parts since the height is limited.

[alecjahn]

Re: Insignia NS L42Q 10A

I've got a 5A fast fuse, "full size" (well, 5x20mm) glass, in my box.

I assume there won't be a problem with wiring that up just for temporary testing? Of course it won't allow the shield to fit.

[tom66]

Re: Insignia NS L42Q 10A

I've got a 5A fast fuse, "full size" (well, 5x20mm) glass, in my box.

I assume there won't be a problem with wiring that up just for temporary testing? Of course it won't allow the shield to fit.

I've done similar things with inverters before; it works fine as a temporary fix. The only problem you may have is very few fuses will take solder, so you will need a holder for it.

[alecjahn]

Re: Insignia NS L42Q 10A

I've got a holder. And just installed it, but was waiting for an "ok" before powering it on.

Now... the backlight does not kick on. Removed the fuse, backlight kicks on as previous.

Hmm?

[tom66]

Re: Insignia NS L42Q 10A

I've got a holder. And just installed it, but was waiting for an "ok" before powering it on.

Now... the backlight does not kick on. Removed the fuse, backlight kicks on as previous.

Hmm?

There might be a short on the T-con then. Check if the 5V or 12V rail goes down.

Also... check the cable from the t-con to the inverter is properly seated. Some TVs have this for a backlight sync feature (reduces flicker.)

[alecjahn]

Re: Insignia NS L42Q 10A

I checked the seating of the connectors a couple times.

EDIT:

12v goes down about 6 seconds after power button is pressed, which is accurate to when the backlight would kick on in its initial state. 5v stays fine.

[budm]

Re: Insignia NS L42Q 10A

Well, it looks like you will have to probe the board for shorts some where. How much is the T-CON from shopjimmy, he does free shipping now. It may be one or two shorted MLC caps some where, they must be carefully handle.

[alecjahn]

Re: Insignia NS L42Q 10A

With my multimeter at 200 ohms setting, a handful of random MLCCs look to be "shorted".

ShopJimmy seems to have them for 55, going by the link you posted. If I search for the number I have on the board (V420H1-C12), I get http://www.shopjimmy.com/catalogsear.../?q=V420H1-C12 quite a few for quite a bit cheaper. Maybe I should pull the trigger and grab one?
(I think they're even cheaper on eBay, allegedly working pulls, but I'm not so sure about that source)

Are these boards the same? Mine is definitely a "D033150"

[budm]

Re: Insignia NS L42Q 10A

Look real close at the tag and number as printed on the board, when I am not sure, I send the picture to him and he will match it for you. I bought many boards from him since when he first started the business and very happy with all the boards I bought, no DOA yet.

[alecjahn]

Re: Insignia NS L42Q 10A

Relevant tags.

Marked as

M$36-D033150-LSQT393310031Y

[budm]

Re: Insignia NS L42Q 10A

The white silk screen on the board "V420H1-C12" is the blank circuit board P/N, as you can see, not all components are put on the board. When they load the board for particular requirement they may leave out some parts or use different value parts, then they will put on that bar code sticker with a bunch of number to identify what this circuit board assembly is made for which LCD panel.
That is why on shopjimmy, it asks you to look at the white sticker on the board.

[tom66]

Re: Insignia NS L42Q 10A

Just remember they are still pulls from units with cracked screens like the ones on eBay. Unsure about how tested they are though...