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.
Please do not work on this unless it is unplugged, using an external, isolated DC supply.
Otherwise it is extremely dangerous.
Otherwise it is extremely dangerous.
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/