Help tracking down a LCD Capacitor - Page 1
Forum section: electronics / general

author: thrillkillriot
author_rank: Newbie
timestamp: December 30, 2011, 08:42:48 pm
content: Hello all i could use some help tracking down a cap labled 223js800v / np 938 pp. Any help would be appreciated because I've worn out my resources.

author: Fraser
author_rank: Super Contributor
timestamp: December 30, 2011, 08:59:53 pm
content: 22nF 800V DC rated ?Where in the circuit is it operating ?

author: thrillkillriot
author_rank: Newbie
timestamp: December 30, 2011, 09:18:08 pm
content: Fairly new to this so I'm uploading a scaled image of the board itself with the spot squared off in white. Thanks for your speedy reply and help!

author: Fraser
author_rank: Super Contributor
timestamp: December 31, 2011, 12:20:20 am
content: It looks like a plastic film type capacitor in resin dipped case.A quick search for capacitors in a "JS" series did find Resin dipped plastic film capacitors from Hitachi but they are no identical.http://www.hitachiaic.com/products/plastic_film_dip_capacitorshttp://www.hitachi-chemical.com/products_capacitors_resin_dip.htmI still think it is likely to be 22000 pF = 22nF and rated at 800V DC. If you can find another capacitor on the PCB with the same marking, get it measured using a simple capacitance meter or multimeter that includes capacitance.From the picture, the capacitor appears to have failed producing burn marks.... it would be well to understand the circuit it resides within as it may have failed as a result of another fault or may have fried other components during its failure.Update:Still can't find your capacitor listed but take a look here:http://industrial.panasonic.com/www-data/pdf/ABD0000/ABD0000CE23.pdfhttp://industrial.panasonic.com/www-data/pdf/ABD0000/ABD0000CE48.pdfhttp://industrial.panasonic.com/www-ctlg/ctlg/qABD0000_WW.htmlIn the first link you will see a data sheet. The part no. for the capacitor bears no resemblance to what is written on the case iteself. There is 105K250H 105K400H and 105K630H shown. The numbers are different to yours but, logic and my past experience, does suggest... "Value / Tolerance / Working Voltage (DC)". The second datasheet link even has 800V shown on the part

author: thrillkillriot
author_rank: Newbie
timestamp: December 31, 2011, 12:42:33 am
content: From what i can tell I'm think it might be related to a general fault tolerance if this makes sense. Would you think a 105k 450 might hold par as well or a whv 183h 800VDC? This is a PSU from a 55 in Samsung LCD. Thanks again for all your great input!

author: eternal_noob
author_rank: Regular Contributor
timestamp: December 31, 2011, 07:12:17 am
content: Too me, it looks like your board is populated with a lot of Panasonic film capacitors (or Chinese copies). Film/foil capacitors usually don't blow up unless the cap itself is faulty or underrated for the job, so I suspect there is something else wrong. If not, I can't see any reason why you can't use other brands and/or maybe increase the working voltage to 1500V.Your ''183h 800VDC'' might do the job.This is a typical Panasonic cap.

author: Fraser
author_rank: Super Contributor
timestamp: December 31, 2011, 02:21:44 pm
content: thrillkillriot,I'm not sure I understand your question, but to be clear, you should fit the same value of capacitor in terms of it's actual capacitance, in your case I believe it to be 22nF (223 marked on cap). The working voltage may be the same or greater but not less. A 1000V or 1200V rated 22nF capacitor would provide some additional voltage 'headroom'.To confirm my original thoughts on the value of the capacitor you could read the numbers off of any of the similar capacitors and have the capacitance of one of those tested to see if it tallies with the writing on the case. If you need any help reading off the value from the capacitor, please feel free to ask.

author: ipman
author_rank: Regular Contributor
timestamp: December 31, 2011, 05:34:06 pm
content: The LCD's inverter is a constant current source, so without load voltage can climb up from the nominal 800V until protection kicks in. That's why sometimes capacitors get destroyed.Before replacing the capacitor, check cables and the lamp attached.

author: ceoscar
author_rank: Newbie
timestamp: June 26, 2017, 11:10:07 pm
content: I have problems with an equal Capacitor. I was looking for but I have not found it. Please can you suggest which one can work.Thank you very much,

author: ceoscar
author_rank: Newbie
timestamp: June 26, 2017, 11:12:00 pm
content: Pictures FYI