Tannoy active monitor schematics required

[Nigelo234]

Could anyone help ? We have a pair of Tannoy 66D active monitors, both have ceased functioning with different faults. The owners manual has no schematics and I would prefer to try diagnostics and repair, with assistance from the Forum.

[Enzo]

Have you contacted Tannoy and asked for the drawings?

I don;t know the units, but may I assume the powers inside are IC based? Either some chip like the LM3886 or the TDA7293, or maybe one of the STK series?

What are these faults?

Start inside with powr supply - both powr amp and preamp. All present?

[Nigelo234]

Enzo. Thank you for your swift response. I have contacted Tannoy, but at present have a zero response.
The faults are as follow, the monitors were un used for months, the were stored in a warm dry dust free enviroment.
* **One unit with power applied and the standby switch active = red led on the standby switch.. press the standby switch, the led on the press switch turns green and the drivers flex to a thump then nothing.
* **The second unit with power applied and the standby switch active = red led on the standby switch.. press the standby switch, the led on the press switch turns green then nothing. but a red led lights on the rear of the cabinet adjacent to the spdif inputs, this led is not labelled or listed in the owners manual.
As you have suggested I am going to proceed testing through the power supplies. The monitors are active and consist of 2 x 6" drivers and a 1" tweeter.