Backlight not working on Panasonic VX2235wm

[brandoon]

Came down this morning to find my Panasonic monitor displaying a blank screen, but the LED light on the front displayed blue (the monitor should be on and displaying). A quick google search and flashlight test later showed that my backlight wasn't functioning.

After reading several posts here, I disassembled the monitor and found the bulging CapXon capacitors that seems to run rampant in these monitors. Of my 8 capacitors I have 5 CapXon and 3 Taicons. None of the Taicons are bulging. Should these be replaced as well? Is there anything else I should do other that replacing the capacitors?

Thanks very much,
Brandon

[retiredcaps]

Re: Backlight not working on Panasonic VX2235wm

Of my 8 capacitors I have 5 CapXon and 3 Taicons. None of the Taicons are bulging. Should these be replaced as well?

The members here recommend replacing all the electrolytic capacitors except the biggest one which rarely, but not never, fails.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

Most members here will recommend that you replace ALL capacitors with reputable brands from reputable sellers. Brands like Rubycon, Panasonic, and United Chemicon are suggested.

If you live in the USA, follow PlainBill's instructions to choose Panasonic FM (preferred) caps. If FM is sold out, then choose Panasonic FC.

https://www.badcaps.net/forum/showpo...33&postcount=2

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

Thanks for the reply. I removed all of the capacitors from the board this evening and have found their matching components at Digi-key per your link. Everything looks the same dimension-wise except for the CapXon 25V 1000uf KF capacitor. My measured dimensions are 10mm X 20mm but the Panasonic FM and FC is 12.5mm X 20mm. One of these capacitors goes into a tight space and I don't think a 12.5mm diameter would fit unless I leave long leads. What should I do?

Thanks,
Brandon

[jetadm123]

Re: Backlight not working on Panasonic VX2235wm

Thanks for the reply. I removed all of the capacitors from the board this evening and have found their matching components at Digi-key per your link. Everything looks the same dimension-wise except for the CapXon 25V 1000uf KF capacitor. My measured dimensions are 10mm X 20mm but the Panasonic FM and FC is 12.5mm X 20mm. One of these capacitors goes into a tight space and I don't think a 12.5mm diameter would fit unless I leave long leads. What should I do?

Thanks,
Brandon

I think you meant Viewsonic vx2235wm? Anyways, the 10mmx20mm size is meant more for computer power supply and motherboard applications where tight spacing is the norm. Try the badcaps.net site. Topcat carries a complete line of caps that should meet your needs.

[retiredcaps]

Re: Backlight not working on Panasonic VX2235wm

My measured dimensions are 10mm X 20mm but the Panasonic FM and FC is 12.5mm X 20mm. One of these capacitors goes into a tight space and I don't think a 12.5mm diameter would fit unless I leave long leads.

Can you post a picture of the board where the fit is tight? Or list the cap values around where there is a tight fit?

I have one idea that might help. For the caps around that tight area, we could go a smaller dimension cap but still the same uF and V. That might free up enough space to get the 12.5mm diameter 1000uf 25V?

If that doesn't work, then

Buying caps from badcaps.net does help support this forum, but badcaps.net doesn't always have the same selection as the bigger distributors.

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

Can you post a picture of the board where the fit is tight?

Here is a photo. There is a spot where a 12.5 diameter capacitor sits nearby so I labeled that for reference.

[jetadm123]

Re: Backlight not working on Panasonic VX2235wm

Here is a photo. There is a spot where a 12.5 diameter capacitor sits nearby so I labeled that for reference.

Not suprised the caps closest to the heatsinked devices went bad. Too much heat. Don't go any higher in diameter as that will put the new cap even closer to the heatsink. If you can go 10mm on the 12.5mm cap, that would also be good.

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

There are several capacitors at Digi-key that are 10mm X 20mm 1000uf 25V capacitors, but they all have 680mA ripple current. For instance Panasonic NHG, Nichicon VZ, and United Chemi-Con KMG. Would any of these work for my situation?

As suggested above I looked at the badcaps.net store and see the Samxon Gt series is the right size with a ripple current of 1.4A. But the store is missing several other sizes of capacitors I'd need.

Also, what are the white and orange putties on the board for?

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

I just went back and looked at some old pictures and realized that I'd messed up on my drawing showing where different capacitors went. The bottom right 10mm circle is the one thats supposed to get the 12.5mm capacitor. It's not that tight so it would fit.

[kc8adu]

Re: Backlight not working on Panasonic VX2235wm

special oem batch.odd size not in datasheets.replace with fm,zl,ect.

[jetadm123]

Re: Backlight not working on Panasonic VX2235wm

There are several capacitors at Digi-key that are 10mm X 20mm 1000uf 25V capacitors, but they all have 680mA ripple current. For instance Panasonic NHG, Nichicon VZ, and United Chemi-Con KMG. Would any of these work for my situation?

As suggested above I looked at the badcaps.net store and see the Samxon Gt series is the right size with a ripple current of 1.4A. But the store is missing several other sizes of capacitors I'd need.

Also, what are the white and orange putties on the board for?

The digikey caps you mentioned are the wrong type of caps for your application. For a little more money, there are several ebay vendors selling recap kits. Type in "VX2235WM kit" in the search window. Be sure to ask the following: what series cap, diameter and make sure the values listed match up with yours. My only fear would be that they may also not have the 10mm caps, but it won't hurt to ask.

If you're asking about the white gunk sticking to the caps, it's an adhesive used to hold the hand inserted parts in place. When the adhesive dries, the board is turned over and surface mount parts are inserted by machine with the adhesive preventing the parts from falling out. Also holds the parts in place during the automated soldering process.

[retiredcaps]

Re: Backlight not working on Panasonic VX2235wm

I just went back and looked at some old pictures and realized that I'd messed up on my drawing showing where different capacitors went. The bottom right 10mm circle is the one thats supposed to get the 12.5mm capacitor. It's not that tight so it would fit.

If you are talking about CE102, you can "lean" the capacitor. You don't need the capacitor to stand straight up and down.

If you think the "leaning" idea is suitable, try the Panasonic FM cap

http://search.digikey.com/scripts/Dk...name=P12379-ND

[retiredcaps]

Re: Backlight not working on Panasonic VX2235wm

As suggested above I looked at the badcaps.net store and see the Samxon Gt series is the right size with a ripple current of 1.4A. But the store is missing several other sizes of capacitors I'd need.

I have mentioned the lack of cap selection for lcds to the owner of this board before.

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

If you think the "leaning" idea is suitable, try the Panasonic FM cap

I'm going to try that. I'll let you know how it all fairs after I get the parts and try to fix it.


Thanks,

Brandon

[brandoon]

Re: Backlight not working on Panasonic VX2235wm

Got the Panasonic FM caps from Mouser today. Soldered them in and the monitor seems as good as new again. Hooray! The 12.5 diameter 25V 1000uf seemed to fit OK.

[retiredcaps]

Re: Backlight not working on Panasonic VX2235wm

The 12.5 diameter 25V 1000uf seemed to fit OK.

Pictures of the lean?