HP-97 Display flickering - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: HP-97 Display flickering (/thread-249014.html) |
HP-97 Display flickering - davorin - 08-28-2013 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? Or something to do we have here 50Hz instead of 60Hz?
Re: HP-97 Display flickering - Marcus von Cube, Germany - 08-28-2013 Do you have a good battery? The battery is required to regulate the supply voltage.
Re: HP-97 Display flickering - davorin - 08-28-2013 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...
Re: HP-97 Display flickering - davorin - 08-28-2013 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 ;-)
Re: HP-97 Display flickering - Marcus von Cube, Germany - 08-28-2013 Replacement battery packs are available online on a well known auction site.
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