I have a Mackie cv1604 which suddenly stopped working. all lights on the channels light up and no sound. help?

Simplest is to use the LR button at the bottom of the channel strips you want to send to the main mix. Make sure you set the gain for each channel in use so that the clip light just occasionally blinked then back off a fraction.
If you want to use sub channels assign the strip to the appropriate one 1/2 or 3/4 and the assign the sub to the main mix and bring the subs up.

That sounds like the amp board died. Mackie parts can be hard to source, and Mackie is really slow to ship, so I suggest taking it to a Mackie authorized service center. Here's a link-

Contact Support Mackie

You need to contact Mackie support for their recommendations. Here's the links-
Warranty Repairs Parts Mackie
Contact Support Mackie

I believe there is an internal fuse in these which, according to a friend who has these, seems to blow occasionally for no apparent reason. He has also had to send two back for replacement and would not buy again, they seem to be inherently unreliable although they sound great.

You say the clip light is always on, as the only clip lights on this mixer are on the effects channel and the master output and you do not say which is on there are a number of possibilities. You may have the effects turned up too far as this should not be showing, just maybe blinking, turn them down on efx2 on all strips as well as on the effects processor and see if this helps. If it does you may be able to find where the hum is coming from by gradually increasing each until you find it.

If you are getting the clip on the main mix master and you are not being deafened and the humming sound is coming from the speakers not the mixer you may have a subsonic signal getting into the mixer. Disconnect all inputs and if this cures it go through until you find where it is getting in and sort that.

If the humming is coming from the mixer it is possible that the smoothing caps on the PSU are dying, you do not say if you are getting normal sound as well as the humming from the mixer.

When asking for help please try to give as much information as possible

You should return it, that's what the warranty is for. Don't even think about trying to sort it yourself

This is vague,,, there are so many outputs, knobs, LED's that I suspect you have not tried the right combination. I have no idea what your signal sources are... mics... tape... etc.

To start, turn the trim control of one channel that you have a signal source connected. Set all the EQ controls and the pan CONTROLS TO 12 O'CLOCK.

Check that you can trigger the clip light with high level of input. Press the solo button for that channel and using a set of headphones listen for any signal... turn the headphone level up and the slider for that channel...

First do your basic checks,,, try EACH mute button and see the LED light... try each solo button and see that each will light AND also that ANY solo light will cause the RUDE solo light to come on...

If you havent ground looped the chanels. Most of the time the chanels need to be cleaned.

Hi kielhunt
It sounds like power supply issues.
You may have bad capacitors and/or bad regulators.
If you have a multimeter you can get in there and check the dc voltages for ripple(ac voltage mixed with dc) or over/under voltages along the +/- 15volts lines.
Good luck

If all other functions work for those channels, the most likely problem is the fader itself. These can fail and operate more like switches rather than faders. Without witnessing the behavior, I can not state that for sure. While these mixers are not the hardest to work on, they are time consuming. The faders can be purchased from Mackie directly. If you need to have this repaired, any shop that repairs audio gear should be able to erpair this for you. Where are you located?

Dan