[Kev4272]

Hi! I just finished a MP566, but I don't have any Mic Input. The signal on the DI seems to work but there's a lot of saturation on it, its almost distortion. I checked the click on the gain switch and I have a click between the Low and the Mid but nothing for the High. I also have no click when I insert a jack in the DI. 

Thanks!

[JPK]

The No Mic issue may come from a damaged 2N7000 (Q1). This component is sensitive to static electricity and is better handled without your shoes on (body grounded).
You can check this by creating a short between the 2 extreme pins of this component. It should activate the mic relay.

I have a click between the Low and the Mid but nothing for the High

This is normal, the high gain is directly controlled by the switch, without a relay.

Do you have a gain variation between the mid and high gain?
Check the DC voltage on TP4. it should be close to 0.

[Kev4272]

You can check this by creating a short between the 2 extreme pins of this component.

By the two extreme pins of the component, do you mean the 0V and the V+ ?

Do you have a gain variation between the mid and high gain?
Check the DC voltage on TP4. it should be close to 0.

I have a big difference of dB between the three of them. The Low gain is the loudest and the Hi Gain the least loud. But I don't really hear a lot of difference in terms of saturation between the three of them.

Do I have to put the black probe on the 0V and the red probe on the TP4? If yes, I am getting 0V

[JPK]

By the two extreme pins of the component, do you mean the 0V and the V+ ?

NOOOO!

Q1 is a component with 3 pins in a row. I mean between the 2 pins which are not the center pin.

Do I have to put the black probe on the 0V and the red probe on the TP4? If yes, I am getting 0V

Correct. This is OK.

[Kev4272]

Q1 is a component with 3 pins in a row. I mean between the 2 pins which are not the center pin.

Alright! So I did it, but I don't hear the mic relay clicking. Does that mean that the Q1 is damaged?

[JPK]

No, it means the issue is in the relay or R26 or D2.
If R26 and D2 are OK, try replacing the relay. Send me an email here for a replacement part.