Viewsonic VX2235wm capacitor relpacement

[egood71]

Okay, I am a beginner at this, so please bear with me. I have been given a Viewsonic VX2235wm LCD monitor. I have been reading the threads for this monitor and have look at all the pics but what I need to know is which capacitor to I need to replace the old ones with?

I have removed the old capacitors.

https://www.badcaps.net/forum/attach...1&d=1289685259

https://www.badcaps.net/forum/attach...1&d=1289685259

There are so many on the distributors websites I don't know which to go with. I do know that I want to go with Panasonic.

I need to get:

1x220uF @ 10V
2x1000uF @ 25v
3x220uF @ 25v

But which series or does that even matter. Thanks for all your help.

[retiredcaps]

Re: Viewsonic VX2235wm capacitor relpacement

There are so many on the distributors websites I don't know which to go with. I do know that I want to go with Panasonic.

But which series or does that even matter.

Panasonic FM is your preferred choice. If it is not available get FC. See jetadm123's instructions at (to buy from digikey.com)

https://www.badcaps.net/forum/showpo...38&postcount=3

[PlainBill]

Re: Viewsonic VX2235wm capacitor relpacement

I do hope you made a chart indicating which cap goes where.

PlainBill

[PCBONEZ]

Re: Viewsonic VX2235wm capacitor relpacement

Convientlty you didn't mention the Series or physical size old caps which makes a proper cross refernce imposible.
- I know, you are new. Common mistake....

I'm going to guess they are all KF Series which is the only mark I can make out in the photos.

KF - 220uF @ 10V - 6.3x11mm - 340 mA / .350 ohms
KF - 1000uF @ 25v - 13x20mm - 1650 mA / .045 ohms
KF - 220uF @ 25v - 8x11.5mm - 550 mA / .150 ohms

If the dimentions are wrong then they are custom ordered caps and the Ripple mA and ESR ohms will also be wrong requiring -guesstimating- from the other caps in the KF data sheet.
[This is why the physical size matters.]

You want caps with the same or more Ripple [mA] -and- the same or less ESR [ohms]

~~
And yeah, if you didn't make a cap map do one now while you still remember where they came from.
.

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

Thanks everyone for the quick responses!

Yes, I did create a chart of the locations of the caps. Thanks for the concerns.

@PCBONEZ:

Thanks for the information about getting the correct sizes, I will measure them and post back or if someone has a service manual for this monitor please let me know. Thanks!

...back to troubleshooting!

[seanc]

Re: Viewsonic VX2235wm capacitor relpacement

I would go for Panasonic FC or FK. I have FM in mine, I think the ESR is too low - the PSU whines in standby.

[Th3_uN1Qu3]

Re: Viewsonic VX2235wm capacitor relpacement

the PSU whines in standby.

Nothing stopping you from applying some lacquer to the transformer.

[seanc]

Re: Viewsonic VX2235wm capacitor relpacement

Do I need to use a special type?
E.g, car lacquer wouldn't be a good idea...

[bonney]

Re: Viewsonic VX2235wm capacitor relpacement

pcb lacquer or nail varnish whatever colour you have

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

Thanks for all the help. Parts are on order and should be here soon. Wish me luck with this!

Thanks!!!

[PCBONEZ]

Re: Viewsonic VX2235wm capacitor relpacement

Do I need to use a special type?
E.g, car lacquer wouldn't be a good idea...

If you are going to open it up to do that then why don't you just change the cap instead and see if it helps.

The transformer isn't the only possible source of the noise.
I don't know this circuit but in some circuits too low of ESR can cause MOSFET Ringing which can present as "Singing MOSFETs". I imagine under certain conditions other types of transistors will do about the same thing.
.

[seanc]

Re: Viewsonic VX2235wm capacitor relpacement

Oh I will be swapping everything for FK if/when I open it up, before I do anything with lacquer.

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

Ok new caps came in and got them in place, but when I power up the display the blue led light just blinks. Any ideas as to what would cause this?

Thanks.

[retiredcaps]

Re: Viewsonic VX2235wm capacitor relpacement

Ok new caps came in and got them in place, but when I power up the display the blue led light just blinks. Any ideas as to what would cause this?

If you have a multimeter, check the DC voltages on the connector between the power and logic board. I'm guessing you should see a stable 5V DC, and possibly 12V or 19V DC (depending on the board).

[alexanna]

Re: Viewsonic VX2235wm capacitor relpacement

Ok new caps came in and got them in place, but when I power up the display the blue led light just blinks. Any ideas as to what would cause this?

Thanks.

You did not indicate what your initial problem was. Did it have a blinking PLED?
Also do you have a video source hooked up?
Al.

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

If you have a multimeter, check the DC voltages on the connector between the power and logic board. I'm guessing you should see a stable 5V DC, and possibly 12V or 19V DC (depending on the board).

Yes, I do have a multimeter. Which connector are you speaking of that I need to check for voltages? Thanks.

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

You did not indicate what your initial problem was. Did it have a blinking PLED?
Also do you have a video source hooked up?
Al.

Alexanna, the initial problem was that this monitor had no screen light up (but was able to see the image with a flashlight) and there was a hum when it was on and hooked up to a video source. Thanks.

[alexanna]

Re: Viewsonic VX2235wm capacitor relpacement

Follow PlainBills's or Retiredcaps sugestions,For the proper way to post pticures of your boards.
It sounds like you may have created a problem.Check all of your soldering for loose joint's.I do what could be described as a wiggle test,By gently rocking the top of the capacitor and watching for any movement on the solder pad.
Just make sure every things unplugged,and discharged.
Al.

[egood71]

Re: Viewsonic VX2235wm capacitor relpacement

Wooooohooooo!!!

Monitor is up and working! Checked all solder points and one was loose, corrected it and now we are in business. This is great, someone gave it to me and said if you can fix it you can keep it! Thanks to everyone for all their help! My first capacitor replacement!!!

[alexanna]

Re: Viewsonic VX2235wm capacitor relpacement

Careful man it's like eating potato chips can't do just one!!!
Al.