Hello,
I’m at the check step of the power supply. I’m supposed to get +5,0,-5V at various places on the board, but I only obtain something like +4.5, 0, -3.9V.
I double checked the orientation of the components, but I couldn’t see my mistake… Any tips ?
thx,
s.
What is the voltage of your power supply?
I have a configurable one, tested 6.5, 9, 12.
I also tried with a non-configurable one, a 12v from my m-audio audiophile, I get the same results.
Which voltage you read at SW0 (the pads for the on/off button or the “bridge” to short it)?
configured with 9V, I read 9 dot something, I have an analog voltmetre…
My voltmetre is configured at 50V (At 10v the needle would reach the limits…)
I had the same issue. This was caused by bad contact at J3 level. Since my DC plug was too big to fit in boards hole, I driled it. and the metal that link the two sides was removed … I was reading 3.3 V at the switch level.
So if you drilled J3, take care of this.
I brought the board to work, but had not time to test it, I’ll do it tomorrow and check what you suggest.
Meanwhile, I remember that when I touch the metal plate of LM 7905 voltage regulator, I get some voltage, but when I touch the other one (LM7805), I get nothing in terms of voltage.
This may give to my kind helpers some cues 
s.
No, this is correct… The metal plate is connected to ground on the LM7805, and to the negative rail on the 7905.
ok, so I obtained -4.99V and 5.60V with a working voltmetre and a working alimentation. Still, this is not correct, what would make such value (5.60) ?
It turns out that it was the 7805. I tried another one, I get the right voltage now.