QSC Audio Players & Recorders - Recent Questions, Troubleshooting & Support

See page 6, left side of printed circuit board, "AC LINE FILTER", fuse F1 (MS-10.250-FU, F10AH 250V) :

QSC Audio... | Answered on Jul 05, 2019

You have a high power amplifier and the work you propose leaves no room for either error or compromise. If, as you suppose, the output is by complementary pair, the transistors must be matched pairs providing equal gain characteristics.

Unless you have seen inside a complete amplifier of the type you are only guessing at the output stage(s) that could be by module or a multiple transistor output. There also might be other driver stage(s) sharing the same heat sink.

The least you will need is a service manual and an internet search produced a number of results on the below link.


QSC Audio... | Answered on Oct 11, 2018

Power supply could be failing

QSC Audio... | Answered on Dec 23, 2017

Are you then saying you have no sound, yet the amp is on? If so, with the unit off, listen carefully to the top of the amp. When you first push the power button, you should hear one click, followed by another click, about 5-20 seconds later. I'm guessing you hear the first click, but not the second. Is that correct? If this is correct, and you are interested in having your QSC repaired, Please visit my website at audioserviceclinic.com. You may contact me there. Thank you.

QSC Audio... | Answered on Feb 06, 2016

As always with stereo amps the two channels are identical, so if one goes wrong you have the other as a control for testing purposes. So if you start by looking and comparing the two channels. that's a start! If a part looks odd on the faulty channel, but is fine on the good channel you have found the problem. You can also do tests, such as touching the two channels with an insulated screwdriver, while powered up. If it buzzers on the good channel, it should buzz on the other channel at that point. Keep away from the power supply and ignore anything that is on it's own, that has no duplicate, or is common to both channels.

QSC GX5 2Channel... | Answered on Dec 31, 2015

That sounds like it could be a power supply issue to the main amp board. Possibly a voltage control regulator function issue?

QSC MX1500A... | Answered on Dec 31, 2015

When you buy anything used there is always the possibility that someone has messed around inside it.
Are these two amps the same you bought? If they are you can open both of them up and see if anything has been changed.
Again if they, are I suspect you will find that someone might have rigged it so the power switch is bypassed. Presumably the switch broke, the person either couldn't find a switch or just couldn't bother to get a new one!
If they are the same model, then the one with the working switch should show you how it is wired correctly.
Don't rewire the other model the same as your good one, till you have replaced the switch. As it could be a safety hazard. I would also advise not using the amp with no power off switch working, till it is replaced. Again due to safety concerns.

QSC Audio... | Answered on Dec 31, 2015

You would have to replace them. If they are no longer available, you would have to modify the amp to accept another brand of terminals. If you need more assistance, or would like to inquire about repairing it, please visit my website at audioserviceclinic.com. You may contact me there. Thank you.

QSC RMX 4050HD... | Answered on Dec 06, 2014

The output of the mixer goes to the input opf the QSC rmx850.

QSC Audio... | Answered on Nov 27, 2014

Try a Google search, or contact QSC. They are still in business.

QSC Audio... | Answered on Nov 19, 2014

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