Repairing a 82022B charger (with P.S. to Geoff Quickfall) - 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: Repairing a 82022B charger (with P.S. to Geoff Quickfall) (/thread-179112.html) |
Repairing a 82022B charger (with P.S. to Geoff Quickfall) - Karl-Ludwig Butte - 02-20-2011 Dear all, one of my 82022B chargers broke some days ago. A first investigation showed that the fuse was melted. But after replacing it, the same thing happened again immedeately. A further search for the root cause showed that transistor Q3 shortcircuited. It's a NPN power type with a "M726" printed on it. Alas I couldn't find any datasheet at the Internet. Does anyone know with which transistor available today I can replace it ? Any hint will be very much appreciated - thank you very much in advance. Kind regards Karl
P.S.: By the way, Geoff, if you're reading this, may I ask how about your book ? Will it be ready for ordering soon ?
Re: Repairing a 82022B charger (with P.S. to Geoff Quickfall) - Ignazio Cara (Italy) - 02-21-2011 Hello Karl, http://www.jacques-laporte.org/HP35%20power%20unit.htm Take care and regards.
Ignazio
Re: Repairing a 82022B charger (with P.S. to Geoff Quickfall) - Karl-Ludwig Butte - 02-22-2011 Hello Ignazio, thanks a lot for your answer - I'll try my luck. Best wishes and kind regards
Karl
Re: Repairing a 82022B charger (with P.S. to Geoff Quickfall) - Karl-Ludwig Butte - 02-23-2011 Dear All, thanks again for the link Ignazio and thanks Jacques for the excellent technical content. I succeded to repair the charger by replacing the defective Q3 with a BD128 which should be available at any electronic shop. A bit more difficult was to find a supplier for the fuse, a so called pico-fuse, which also was defect. For people living in Germany I found it at Reichelt Elektronik. Best wishes and kind regards Karl
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