M-Audio Studiophile AV30

[MerceanCocout]

I'm looking for a schematic for M-Audio AV30 Studiophile speakers.

[doctor]

I'm looking for a schematic for M-Audio AV30 Studiophile speakers.

What is a revision of the board?

[MerceanCocout]

What is a revision of the board?

V2.0

A couple capacitors and at least one zener diode has blown. I'm trying to determine the part number of the zener diode. If I test it, it looks like 8 V, but from what I can make out from the part number it looks like it should be 12 V, so I'm at a bit of a loss.

[doctor]

V2.0

A couple capacitors and at least one zener diode has blown. I'm trying to determine the part number of the zener diode. If I test it, it looks like 8 V, but from what I can make out from the part number it looks like it should be 12 V, so I'm at a bit of a loss.

Version 2.0 does not exist in the M-Audio database,
but I hope that ver.3.0 will be suitable as well.

Good luck.

[MerceanCocout]

From what I can see the schematic matches what's on the board, so it should be good for my purposes. Thanks, doctor!

[stuckinstandby]

Thanks for posting this doctor. I have the same problem with my AV30 speakers. Zener diode Z1 completely burnt out and a lot of failed caps. The board is V1.0. I'm guessing it'll be more or less the same but do you have the schematic for it? or a parts list?

Assuming the diodes are the same on the V1.0, can anyone suggest a replacement?

Someone on the m-audio forum thought the markings read 1n4742A, which is a 12v zener - (1N4742A - VISHAY - DIODE, ZENER, 12V, 1.3 W | Farnell)

[MerceanCocout]

Someone on the m-audio forum thought the markings read 1n4742A, which is a 12v zener

That was me. The markings are very faint so I am not sure of that part number, but the V3 schematic shows a 12V zener, so even if it's not the exact part number it should work.

[oc disorder]

Maybe as it's a common fault and likely to be repeated it may be worth redoing the power supply with 12v regulators.
Or at least without cutting the leads from the new zener wrap them around a small screwdriver making little heat dissipators
between the diode and the board at either end.

[doctor]

Maybe as it's a common fault and likely to be repeated it may be worth redoing the power supply with 12v regulators.
Or at least without cutting the leads from the new zener wrap them around a small screwdriver making little heat dissipators
between the diode and the board at either end.

Hi users of the AV30,

In the ver. 1.0 the 15V zener diodes are used, while the ver. 3.0 uses the 12V.

If the zener’s package is through hole, the ZPY series zener manufactured by Diodes Inc.
is preferable due to its high reverse current. Any of the ZPY12/ ZPY13/ ZPY15 may be used.

Two conditions must be checked:

1. In order to zener works properly the current (Ir) through the current-limit resistor (R57 and R58 for both versions) must not exceed max reverse current (Izt) of the zener diode

Ir = Ur [V] / R [Ohm].

Measure the Ur - voltage drop on the resistor (R = 100 Ohm) and compare Ir with Izt
from datasheets for used zener.

2. Power dissipated on each resistor Pr = Ur [V] x Iz [A] must not exceed 1÷1.5W
(due to used 2W resistors).

Good luck.