I have found the problem on my M-Audio BX5a monitor is also a 25V 6800uf power filter capacitor problem, only mine popped like a party popper---the other one is okay. The question I have is that it i

http://mr-ives.blogspot.nl/2011/09/mending-pair-of-m-audio-bx5a-monitors.html

its most likely bad capacitors inside the monitor. take it apart and look for 2 big black caps, there located right by the plug for the power supply on the PCB. they should say 25v 6800 uf.

if they are bulging out on the top and or have goo oozing out of them, there bad. these caps commonly go bad in these monitors because there rated WAY too low.

If you have to replace them, id go with some 50v 6800uf caps. they will be bigger and you'll have to solder leads and mount them elsewhere off the PCB, but you will NEVER have to change them again in your lifetime! (prevented no one else messes with it! )

get some higher rated speakers as this will happen time after time, or you could turn the bass down lol

Check the capacitor, if its swollen or rusty it needs replacing, also check the fuse.

I have a pair of BX5a monitors hooked up to a video editing suite. One of the monitors is off. They are powered to a working electrical supply. They are driven off a Mackie DFX-6 with a 1/4" unbalanced connection. No blue light on the monitor, no sound or hissing on that...

It is most likely that the filter capacitors on the power inverter board have failed. I took mine apart and found seven swollen capacitors on the this board, they fail prematurely and seem to be the only thing wrong with the unit. I replaced them and now it is working just fine.

six 470uf 25v electrolytic capacitors and one 220uf 25v Capacitor.

you should not attempt to repair this yourself unless you have some electronics training since there is a shock hazzard involved and also these capacitors will blow apart if they are installed incorrectly (very messy experience).

Not sure i can help with the led problem but i just fixed a hissing problem with one of my BX5a monitors. It developed a hiss when on (both tweeter and bass) and a very loud thump when switched off. I found a slightly swollen power filter capacitor on the internal board. They are the two biggest black capacitors, labelled as 25v 6800uf. Only one of these was bulging. The tops of these should be totally flat. The indented X on top of the caps make any bulge easy to spot. Worth opening it up and having a quick look. I could only find 35v 6800uf caps at my local electronics store but they did the job ($3 each). I swapped both out and it's now working great. An easy DIY fix, just be sure to always have the power cord unplugged before you put your hands anywhere near the guts of the thing. Hope it helps.

If the power supply is not wqrking then it is the invertor unit that has dies.
Replace the monitor is the best advice- If it that recent out of warranty may be worth contacting 'viewsonic to see if they will discount you one.

You can use a higher voltage capacitors without problems its the value of uf that should remain the same. But sometimes you can use a higher uf like a 330uf can be replaced with 470uf but never go lower than the original value on uf and voltage. But you can safely use 6800uf 25v or 35v.