Samsung le23r88bd (r)

[selldoor]

Re: Samsung le23r88bd (r)

Hi - digikey link fails what does it say on the cap can only really see 600v

[Berts]

Re: Samsung le23r88bd (r)

I've checked both RS components and Farnell but cannot find the exact component. :-(

I cannot even find a Capacitor with the capacitance of 0.018uF

Does anyone know what else I could use or where to source this part?

Thanks

[Berts]

Re: Samsung le23r88bd (r)

Says 18nJ 630v 389 MKP on-top of the Cap and CM802 on the board.

Here is the link that took me to the Digikey part. https://www.badcaps.net/forum/showth...ighlight=CM802

And attached is a print-screen from the Digikey website.

[selldoor]

Re: Samsung le23r88bd (r)

How about one of these I cant see an 18nf either
perhaps Tom can advise if a 22nf will be ok
What is the leg spacing on yours


http://cpc.farnell.com/vishay-bc-com...vac/dp/CA06022

[Berts]

Re: Samsung le23r88bd (r)

ok

[Berts]

Re: Samsung le23r88bd (r)

Another forum that lead me to believe it was the 630v Cap

http://www.electro-tech-online.com/r...psu-fault.html

[Berts]

Re: Samsung le23r88bd (r)

16mm leg spacing. I know the Digikey one is 10mm but I can make that fit if I leave the legs long. I am tempted to just buy it, but £12 postage for a 30p part OUCH!!

[selldoor]

Re: Samsung le23r88bd (r)

Ok - need to get our posts back in sync
What is the distance between your caps legs. I cant find an 18nf cap but there are 15nf and 22nf - the example I posted IS 630vDC but they also quote the ac voltage.

Edit

Damn crossed again

[selldoor]

Re: Samsung le23r88bd (r)

Ok here are 3 that I think will do if Tom can confirm 22nf is ok
One is 1000v but you have to buy 5
the other two are 630v - looks like you can buy 1.
If they are ok I can help if delivery is exhorbitant or min order applies.

http://cpc.farnell.com/vishay-bc-com...20This%20Range

http://cpc.farnell.com/vishay-bc-com...New%20Products

http://cpc.farnell.com/vishay-bc-com...New%20Products

[Berts]

Re: Samsung le23r88bd (r)

Thanks Selldoor, I have read on the forum that someone used a 1000v without any problem. But I will wait for Tom to confirm before ordering. I don't mind buying 5.

thanks again

[tom66]

Re: Samsung le23r88bd (r)

I cannot confirm either way as I'm not certain on what decisions the manufacturer made in designing it. You could place a 10nF and 8.2nF in parallel. Th3_un1qu3 is the best to ask about this as he is well versed on SMPS design.

[Berts]

Re: Samsung le23r88bd (r)

Cheers Tom is there any way of contacting Th3_un1qu3 to ask his opinion on this?

[Berts]

Re: Samsung le23r88bd (r)

I have ordered the 22nf 630v one so hopefully that will do it.

[Th3_uN1Qu3]

Re: Samsung le23r88bd (r)

That cap right there looks like it is part of the snubber circuit on the transformer primary. It is fairly critical because if the cap is too small, then there is a risk of spikes killing the primary transistor, if it is too large, it'll cause excessive dissipation in the snubber resistor in series with it - RW801 i think it reads on your board. Since that cap is blown, are you sure the mosfet is good?

In this case, i would go with 15n as it is slightly closer to the original value. Edit: You've posted before me. Since you ordered the 22n, i would also beef up the power rating of the resistor in series with it. That looks like a 2W or 3W there, see if you can fit a 5W somehow.

[Berts]

Re: Samsung le23r88bd (r)

Thanks for replying Th3.

For one I am not 100% sure the cap is bad but it is the only one with signs of damage and it seems a common problem with these boards. I have just ordered a Cap meter to allow me to test future caps but at the moment I have no way of knowing.

How would I test the mosfet?

Is the 22n a definate no-go as I have just ordered it?

[Th3_uN1Qu3]

Re: Samsung le23r88bd (r)

How would I test the mosfet?

Erm... wait. You said the set does turn on, just that it gets no picture or backlights. That means the mosfet is good, if it were blown you would simply get no power.

Is the 22n a definate no-go as I have just ordered it?

No. It will simply cause higher power dissipation in the snubber resistor i've mentioned earlier, which may, or may not be trouble. Do you have a temperature probe on your multimeter? Btw, check that resistor as well, it could have increased in value or failed open.

With the capacitor blown, the spikes caused by the leakage of the transformer make their way to the secondary side, which could cause some of the circuitry on the main board to shut down to protect itself, hence no picture. Same thing if the resistor has failed - so be sure to check that too - measure it with your multimeter on the 200k or 2000k range (can't see all color bands from the picture, but it's likely to be in the 100s of Ks), and compare with its color code. Replace if the measured value is more than 5% higher than what it should be.

[Berts]

Re: Samsung le23r88bd (r)

OK thanks mate, much appreciated. :-)

[Berts]

Re: Samsung le23r88bd (r)

Just an update, I replaced the bad cap and the TV is now working. So the wrong value cap had no effect on the function. Hopefully it stays that way.

Thanks again for helping

[jeszke]

Re: Samsung le23r88bd (r)

hi there I have a Samsung le23r88bd it use to take several time to get it to switch on now it wont come on unless I put a hair dryer on and heat it up I have fitted a new power unit and still have the same problem can any one help thank you

[tom66]

Re: Samsung le23r88bd (r)

Are you heating the power board or main board? Or something else altogether?