I bought a broken Yamaha 640 Powered Mixer.Can I fix it? Let's take it apart and see...

I broke my own rules and bought a used piece of audio equipment without bringing test equipment with me to verify it works before handing over the cash. when I finally got around to resting it, the main 300 watt amplifier did not work. the sound came through very cracked up and with the slightest amount volume the protection light kicked in. I suspected a cold solder joint... Let's see if I was right....

[@jackking9208]

Consistent problems with oxidation in the amp buss / bridge assign switch on the front of these. Outside of that, I seldom encounter trouble.

[@maxdelmonte724]

Glen saw your whole video and was glad you were able to fix your amp. I also bought a similar amp on Offerup. Mine is EMX 660. It turns on but no sound coming out. I have no experience in fixing electronics. Might take it to a local music shop in Grayslake Illinois. Take care

[@GlennsSpeedShop]

Are you familure with how they operate? I have about 12 Powered Mixers, and a couple times I brought one home and was scared that it was broke, then played with it a bit and found it to be operator error.

[@revup67]

Glenn thanks for this upload. Encouraging. We have an EMX 640. The RCA inputs keep cutting out as when using an Ipod with a male 3.5mm into the iPod and RCA outs to the 640. When that began failing, I began using the 1/4" inputs with the same cord and 1/4" male adapters. This too began shorting out. I then took a sock wrencg and tightened down the female 1/4" inputs adjacent to the RCA inputs. That work for a short while and it shorts out again thus gave up on the RCA and Aux Input 1/4". Currently, I'm using Input #6 with 1/4" stereo inputs from the Ipod and it sounds unnatural. Hoping to get the RCA inputs working again but have not taken apart this EMX 640. Might you have any suggestions as to what you believe has gone wrong? - Thanks for any help.

[@thedailybench2527]

I have 2 peavey powered mixers and 1 Sampson. I also have a old sunn amp. As well

[@leonboz5690]

Hello Glenn, I bought a used Yamaha emx 640. But when I connect my keyboards there is a noisy sound. It can't be due to the keyboards and cables. Because I've been using them until now. Do you have any idea how I can solve the problem? I suspect a couple of capacitors need to be replaced.

[@nickbelluomini3381]

Not 300 watts a side thats the 660. Yours is 200 a side hence 6 -channel 40 -400 watts

[@Fireship1]

Would this be a good powered mixer to use for a small karaoke setup in a bar?

[@GlennsSpeedShop]

Yes it would be perfect!

[@Fireship1]

Thanks for responding. I picked one up!