noisy power from Viewsonic LCD screen 12V SMPS

[bestsystem]

is there anyway to condition the output current from a Viewsonic LCD screen 12V SMPS??

Can i pass the current through an array of (low esr+ polyesters) capacitors to filter some noise away?


exactly this one

[tom66]

Re: noisy power from Viewsonic LCD screen 12V SMPS

Probably a loose coil vibrating due to magnetorestriction. The coil needs to be glued.

The trouble with these supplies is that they are welded shut. You can break them open but after repairing them you're going to need a lot of glue to stick them shut.

A new supply can be found for less than $10, though...

[bestsystem]

Re: noisy power from Viewsonic LCD screen 12V SMPS

not the sonic noise, actually I mean ripple current

[PCBONEZ]

Re: noisy power from Viewsonic LCD screen 12V SMPS

Why do you think it's noise from the brick?
.
You can get junk on the screen by using video cables without a Ferrite.
See pic.
.

[Th3_uN1Qu3]

Re: noisy power from Viewsonic LCD screen 12V SMPS

He didn't say if he actually uses the supply for the monitor... maybe he's trying to power something else with it.

[PCBONEZ]

Re: noisy power from Viewsonic LCD screen 12V SMPS

That's right.
He didn't say - either way.
.

[filesponge]

Re: noisy power from Viewsonic LCD screen 12V SMPS

Hi. I'm not sure of the actual problem you're having on this one on this one, but i'm assuming that by saying you want to remove noise from the display itself? Possibly a very slight blurring or shimmering of the picture ?

If that's the case, it's possible that the fault is on the actual board at the rear of the screen, and no amount of other changes will affect it
As a wild stab in the dark, i'd say . . . .

Check the screens menu, and see if you can alter its phase settings from in there,

or try a different PSU (i guess thats already been tried?),

or, have a look at the back of the screen on its board, reseat all the connections.

I've had a few older screens where they are even adjustable inside by a tiny pot, though i've not seen such a thing for a while on the bigger sizes now like 19 and above.

With things like this, i usually just throw another screen in and see if it's doing the same. Any screen will do, though the picture may be off to the side, and if you use a widescreen for testing you'l only get a square picture instead, but all normal screens below 22 inch are interchangeable as long as the connections match (from what i've seen in the UK anyway).

[bestsystem]

Re: noisy power from Viewsonic LCD screen 12V SMPS

I am using it for a 25W speaker amp.

Read it first: I know all auidio guys will say use a toridal transformer instead. but there are 3 reasons for me to use smps.
1. very convient, light weight
2. efficient, low temperature.
3. The most important point is I have achieved a very good result without a tiny trace of noise and hum before, using another 12 V SMPS. (1'm sure it's a smps)
(borrowed from a router with longer 12V plug so that I have to put it back after a few weeks.)
The only changed variable is the SMPS, so it cant be other things but the purity of 12V DC

[Toasty]

Re: noisy power from Viewsonic LCD screen 12V SMPS

Crack or cut it open along the seam and re-cap it. Probably all it needs.

[kc8adu]

Re: noisy power from Viewsonic LCD screen 12V SMPS

and some good supply bypass caps at the amp.
i see lots of these bricks die of bad caps.esp the ones on sanyo sets.

Crack or cut it open along the seam and re-cap it. Probably all it needs.