Incorrect voltage

Hey guys,

I started testing the voltages and it seems that i am not getting -8V on the blue pin. Other voltages are ok ( 3.3 , 5 and 8 ).

I have the feeling there is something wrong with IC5 ( 7908) because i see no voltage on any of the three pins (same when measuring D4).

What could the problem be ? How can i further debug ?

Are you using the right kind of power supply? Tell us more about it.

Make sure you are using an AC/AC adpater not and AC/DC adapter.

I have a lab supply (Rigol) and limited the voltage to 9V and current to 1 Amp. But it is a DC lab supply, that is for sure. I guess that seems to be wrong

You need a 9V AC supply. It’s written in many places, including on the board :slight_smile:

Yeah, you are right, apologies for not having read it all through. I will get myself tomorrow an AC power supply

Who wants this as a Sticker? :wink:

Hah - Those would be excellent stickers. It’s always good to have a reminder of sound advice.

heh. I got an AC power supply and now I do receive the -8V. One step further.