Hi
This mixer uses a SMPS. When I turn it ON, it takes approx 3 mins or at times more for the power supply to start up. I heard someone saying it is normal for this mixer. Has someone worked on this mixer before and is it normal for the delayed SMPS start up.
Thanks.
This mixer uses a SMPS. When I turn it ON, it takes approx 3 mins or at times more for the power supply to start up. I heard someone saying it is normal for this mixer. Has someone worked on this mixer before and is it normal for the delayed SMPS start up.
Thanks.
Np startup, delayed startup or temperature dependent startup is not unusual in SMPS.
Usual cause is electrocap smoothing supply to controller chip on primary side of the SMPS.
I forget the details of this A&H supply, if you can post schematic I might be able to point out which caps need replacing.
Dan.
Usual cause is electrocap smoothing supply to controller chip on primary side of the SMPS.
I forget the details of this A&H supply, if you can post schematic I might be able to point out which caps need replacing.
Dan.
Replace with same value but 105℃
C1, 2, 3, 4(if fitted), 21, 28, 29, 30 and 31.
Common problem on older SMPS supplies.
You will not see a fault again for another 10 years.
C1, 2, 3, 4(if fitted), 21, 28, 29, 30 and 31.
Common problem on older SMPS supplies.
You will not see a fault again for another 10 years.
While you have it apart, check the startup resistor (R22, 150k, 1W). These have a habit of going high because they have such a high DC voltage across them.
If the desk was plugged in for a bit, but not long enough for it to come to life, then bear in mind the main smoothing cap (C27) will likely be charged, especially if R22 is o/c. Avoid touching the rear of the PCB until you've checked (and discharged if needed).
Service manual available direct from A&H: https://www.allen-heath.com/media/GL2200-SERVICE-MANUAL.pdf
Cheers,
Mark
If the desk was plugged in for a bit, but not long enough for it to come to life, then bear in mind the main smoothing cap (C27) will likely be charged, especially if R22 is o/c. Avoid touching the rear of the PCB until you've checked (and discharged if needed).
Service manual available direct from A&H: https://www.allen-heath.com/media/GL2200-SERVICE-MANUAL.pdf
Cheers,
Mark
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