LG Flatron 1950s-sn 2 sec to black

[retiredcaps]

Re: LG Flatron 1950s-sn 2 sec to black

Mouser doesn't have the minimum quantity 10.

2.2nf

http://ca.mouser.com/ProductDetail/A...2bjhPUBQxBo%3d

15nf

http://ca.mouser.com/ProductDetail/A...Dz9dZLqFHZw%3d

Again, I have no idea if these are the right ones, but just want to make you aware of the min quantity = 1 versus digikey quantity = 10.

[sceva]

Re: LG Flatron 1950s-sn 2 sec to black

The mouser ones look a little large. Mine are about 1mm wide, 2 mm long, and a little less than 1 mm high. In inches it is .0394 x .0787 x .0394. The smd only has a metal cover on each end. Will wait and see if anyone has further advice.

Size and capacitance is all I am sure of. Don't know if voltage, tolerance, or operating temperature makes a difference.

I did find a service manual at eserviceinfo.com but it did not seem to have these parts listed as replacements. I cannot upload the file - two large for the forum, but for future readers you can get it by going to the following links, downloading part 1 and 2, and then uncompressing it with a program like 7-zip.

http://www.eserviceinfo.com/download...0S_L1950S.html
http://www.eserviceinfo.com/download...0S_L1950S.html

[retiredcaps]

Re: LG Flatron 1950s-sn 2 sec to black

The mouser ones look a little large.

I didn't do an extensive search so they may have more sizes than the ones I found. I just picked the first one that had min quantity = 1.

I also noticed they come in various voltages.

[sceva]

Re: LG Flatron 1950s-sn 2 sec to black

I can't find anything that seems to be the same size and is either in stock or without a minimum quantity order. I also can't find the same parts on my old boards. I can't afford to put more than $10 into a monitor to make it worthwhile, so I guess I will be scrapping this one. I already have put way too much time into it. But I have gotten a lesson on the sense circuit and practice with removing and soldering smd's so all is not lost. Thanks to everyone for their help.

[retiredcaps]

Re: LG Flatron 1950s-sn 2 sec to black

I also can't find the same parts on my old boards. I can't afford to put more than $10 into a monitor to make it worthwhile, so I guess I will be scrapping this one.

Maybe post something in buy/sell forum here and maybe some kind person will donate the part from an old board for the price of postage? Postage shouldn't cost more than a stamp for such a small part. You may donate $1 via paypal to them?

[sceva]

Re: LG Flatron 1950s-sn 2 sec to black

I am guessing this is either a very obvious or stupid question, since I haven't read about it elsewhere... What is the danger of leaving the shorts in place and using it as is if I can't find the replacement parts? What are the potential dangers?

[PlainBill]

Re: LG Flatron 1950s-sn 2 sec to black

I am guessing this is either a very obvious or stupid question, since I haven't read about it elsewhere... What is the danger of leaving the shorts in place and using it as is if I can't find the replacement parts? What are the potential dangers?

I'm going to make a SWAG here and say that 10% of monitors fail because of a problem in the inverter. Either a ccfl breaks, a bad solder joint causes an open, etc.

By leaving the shorts in you are disabling the overvoltage protection. What are the possible consequences. The most obvious is that the output voltage would rise, and eventually eventually arc somewhere. The most likely target would be the inverter output transformer would short, overloading the drivers, and probably creating a small stink. A fire is a possibility, but I would say the chance is remote.

The other important considerations are when and where it fails. If it fails two weeks after you sold it, you have an unhappy customer. If it fails in 4 years, the customer will be around asking if you have a 28" LCD monitor at a good price.

I would suggest cutting the risk. I haven't reread the thread, but I believe these caps are used in the voltage divider. Instead of leaving a short in place, replace the pair of caps with the next higher single cap available.

PlainBill

[sceva]

Re: LG Flatron 1950s-sn 2 sec to black

I would suggest cutting the risk. I haven't reread the thread, but I believe these caps are used in the voltage divider. Instead of leaving a short in place, replace the pair of caps with the next higher single cap available.PlainBill

That sounded like a reasonable solution. I replaced the two faulty caps with one that is about twice as high (which was the lowest I could find) and so far it is working well.

Thanks once again.