HP-97 Display flickering

[davorin]

Good morning from Switzerland ;-)

Just received a HP-97 this morning and after some resoldering it seems to work.

One question though:

Is the noticeable display flickering normal?
Especially the flickering is heavier in the left hand digits.

Or something to do we have here 50Hz instead of 60Hz?

[Marcus von Cube, Germany]

Do you have a good battery? The battery is required to regulate the supply voltage.

[davorin]

Pretty dead battery pack ;-)

But thanks for pointing me in the right direction...

Added a small 100uF capacitor across the 5V power supply, close to the AC input where it says "+" and "-" on the PCB...now the flickering has gone and also the printer motor moves...though one gear is worn out...

[davorin]

Well....voltage is a little too high now with the capacitor....

Gonna use a standard 5V USB power adapter now to be on the safe side ;-)

[Marcus von Cube, Germany]

Replacement battery packs are available online on a well known auction site.