HP-19C Repair Odysee

[Artur - Brasil]

Your machine can be restored somehow, I'm sure. If the motor moves to HOME position at power up, this proves that at least ACT and PIK and ROM chips are working, because moving the motor is an active software part. Did you check the Display Enable signal VDISP ? 1818-0432 U7/pin 5 must be High

Bernhard
[/quote]

Yes, there is 5V on it, but I had to remove the display for taking such measure, as IC is under it.
Well, if you don't mind, here my measures for top board (without keyboard and display), taking pin 1 of 12 pins connector as 0V reference:
1 0V (reference)
2 5vdc
3 0
4 -12.3
5 0
6 square signal 5V 10.42kHz
7 6.20V - some little ripple (100mV)
8 5V
9,10,11,12 5V

The 1818-0432 IC (also pin 1 of 12 pins connector as reference)
123468 sawtooth 3.289kHz signal, 3.19V
5 5vdc
7 9 0vdc
10 6,16vdc
11 thin-pulse 3,289kHz
12 0
13 thin pulses
14 0
15 183,8kHz, 19,8vpp, 7,08v rms
16 same as 15
17 -12Vdc
18 0

DISPLAY PINS (display installed) - from left to right
1 2 3 4 5 7 sawtooh from 3V to 5V - 3,289kHz
6 8 0Vdc
9 ... 21 3,79vdc

And the other IC - 1820-1629?
I tested the display inserting + probe to holes on the left (1-9) and - probe on holes 10 - 21
The left ones controls the segment on each digit; the right ones the digit.
Comparing the voltages present on its pins, it will not turn on, as the left ones are above 3V and the right ones at 3,8V - only 1,2Vmax of difference...

Again, I move the printer head by hand, turning the axe, and when the power is applyed, the head goes full left and goes full right and stop.
Best regards and many thanks for your precious knowledge!
Artur