Calibtation Failed

Edukits EDU09
1

I have just finished to sold my EDU09 and I have the messge “CALIBRATION FAILED”.
I read all the posts concerning this problem and perform all tests, but it does not work.

Calibration results are :

CH1 offset at 5V/div : 161 OK
CH1 offset at 1V/div : 201 FAIL
CH1 Y-position low 32
CH1 Y-position mid 128
CH1 Y-position high 219

I have measured the points as pointed out by VEL255 and my results are:

A = 1.65 V
B = 0.43 V
C = 4.47 V
D = 2.81 V
E = -2.58 V
F = 0.75 V

Thank’s for your help.

2

The voltage F is not OK. Should be -5V.
Please check D3, D4 connection and ZD1 polarity.
viewtopic.php?f=46&t=9325

3

[quote=“VEL255”]The voltage F is not OK. Should be -5V.
Please check D3, D4 connection and ZD1 polarity.
viewtopic.php?f=46&t=9325[/quote]

Thank’s for you answer. In fact I made a mistake, I check again and the voltage F is -5,14V. D3 and D4 and their connexion seem to be good. I do not known what I have to do ?

4

I mesured these voltages for IC2 :
1 5,07
2 0,21
3 1,28
4 -5,15
5 0
6 0
7 -1,67
8 5,15

Reading the posts it seems not good ! I tested the resistors, which seem ok !!!

5

I return today the EDU09 for inspection/repair to you at Gavere.