I have two dead Allen and Heath Zed6 mixers.
Mixer 1 is a zed6fx
Mixer 2 is a zed6
I was listening to music on mixer 1 when it lost power. No lights. Switched off and on. Nothing. Dead.
I checked continuity of the mains cable and fuse and checked mains was coming out of the mains cable into the 3-pin socket on the mixer.
I opened the mixer followed the volts to an internal pcb mounted fuse and ordered a replacement.
I replaced the internal fuse.
Switched the mixer on. Nothing. No lights. Dead.
I swapped it with mixer 2.
For several weekends, I would listen to music through it for a couple of hours until a week ago it lost power. Exactly the same as the first mixer1.
What is killing my mixers?
How do I check this?
How do I fix this?
Does anyone have a clear pdf of the process circuit diagram?
Mixer 1 is a zed6fx
Mixer 2 is a zed6
I was listening to music on mixer 1 when it lost power. No lights. Switched off and on. Nothing. Dead.
I checked continuity of the mains cable and fuse and checked mains was coming out of the mains cable into the 3-pin socket on the mixer.
I opened the mixer followed the volts to an internal pcb mounted fuse and ordered a replacement.
I replaced the internal fuse.
Switched the mixer on. Nothing. No lights. Dead.
I swapped it with mixer 2.
For several weekends, I would listen to music through it for a couple of hours until a week ago it lost power. Exactly the same as the first mixer1.
What is killing my mixers?
How do I check this?
How do I fix this?
Does anyone have a clear pdf of the process circuit diagram?
This appears to be the supply schematic.
Much of the power supply circuit has no isolation from the AC line.
This is a very bad and unsafe idea. Probably there has been a cascading failure.
To troubleshoot the circuit, look for bad parts before the transformer.
To check operation, do not plug the unit into the AC line.
Instead, connect a variable DC power supply across C7.
Raise the DC voltage gradually and check the operation.
Much of the power supply circuit has no isolation from the AC line.
This is a very bad and unsafe idea. Probably there has been a cascading failure.
To troubleshoot the circuit, look for bad parts before the transformer.
To check operation, do not plug the unit into the AC line.
Instead, connect a variable DC power supply across C7.
Raise the DC voltage gradually and check the operation.
Its a standard SMPS as far as I can tell.
This is a known issue apparently: https://community.allen-heath.com/forums/topic/zed-6-power-supply-issue
also here: https://www.eevblog.com/forum/repair/smps-repair-allen-and-heath-6-channel-mixer/
Diode D7, the SB1100 may be shorted.
https://www.eevblog.com/forum/repair/smps-repair-allen-and-heath-6-channel-mixer/