Thank you for the feedback.
It’s nice you got both of the EDU09 kits working now !
It seems there was no connection between C30 and C31.
You measured -4.97V on C30 but there was no -5V voltage on C31, as should be.
Hello, im another newbie looking for wisdom and some pointers in the right direction, having put together the edu09 kit i’m getting a similar problem of failed calibration.
Ive checked T1, T2, T3 and ive got them in the right places;
Voltage across ZD1=0.69v
checked the charge circuit and get the following;
A=1.69V
B=0.37V
C=4.36V
D=2.5V
E=-4.84V
F=0.69V
Checked Diodes
D1= 0.290
D2=0.282
D3=1.00
D4=0.286
D5=0.287
D6=0.285
D7=0.165
based on this i’ll get a replacement D3
R18=2.66kohm
R19=4.33kohm
R23=8.43kohm
R25=10.57kohm
R27=19.89kohm
R23 and R25 have changed significantly now they are in the board, is this right have i damaged them in soldering them in place?
ive checked C20 and C21 and the link is in place and also to T1 and T3
I too had a problem with IC2 orientation
chip now orientated to dot bottom right pin1 (closest to SK1)
with USB plugged in i get the following voltages
Pin1=0.69
Pin2=0.37
Pin3=0.17
Pin4=0.69
Pin5=0
Pin6=1.56
Pin7=0.69
Pin8=4.93
USB connector
Pin1=4.93V
Pin2=0.01V
Pin3=3.03v
Pin4=0V
Will post results again after swapping out D3 and D7
should i be looking to do anything else?