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HP 32SII success and woes
02-28-2015, 03:52 AM (This post was last modified: 02-28-2015 04:35 AM by Sanjeev Visvanatha.)
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RE: HP 32SII success and woes
After purchasing the silicon diodes, some test leads and a new temp controlled soldering station, I embarked on repairing this 32SII. I was confident enough that the capacitor was alright.

The first step was to find a place to mount the silicon diode. The negative battery terminal was one spot I had considered, but the metal terminal there is thick, and it is not easy to work on that side. The positive terminal is connected to the PCB, and is very springy, so I decided to place it there.

The positive terminal has two small holes in the arm leading to the PCB, so I decided to cut a section between those holes and solder the silicon diode to the holes.

   

After cleaning the zebras, centering the LCD and reattaching the PCB (Twisties worked!), I was able to turn on the calculator and see positive signs of life. No more garbage display, and the self test passes with flying colours. I see about a 0.6V drop after installing the silicon diode. I read about 3.5V, a bit lower than what Katie had quoted. No low battery indicator either!

   

   

Last step is to close the case off. With the addition of the diode, I will have to enlarge the slot in the back case that goes over the positive terminal.

-- Sanjeev Visvanatha
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Messages In This Thread
RE: HP 32SII success and woes - renif - 02-10-2015, 01:56 PM
RE: HP 32SII success and woes - rprosperi - 02-11-2015, 02:12 PM
RE: HP 32SII success and woes - rprosperi - 02-11-2015, 10:55 PM
RE: HP 32SII success and woes - rprosperi - 02-12-2015, 12:21 AM
RE: HP 32SII success and woes - rprosperi - 02-13-2015, 12:51 PM
RE: HP 32SII success and woes - rprosperi - 02-13-2015, 06:53 PM
RE: HP 32SII success and woes - rprosperi - 02-14-2015, 02:03 PM
RE: HP 32SII success and woes - jebem - 02-16-2015, 09:36 AM
RE: HP 32SII success and woes - jebem - 02-16-2015, 03:22 PM
RE: HP 32SII success and woes - jebem - 02-17-2015, 03:05 PM
RE: HP 32SII success and woes - jebem - 02-20-2015, 03:39 PM
RE: HP 32SII success and woes - Sanjeev Visvanatha - 02-28-2015 03:52 AM
RE: HP 32SII success and woes - rprosperi - 02-28-2015, 04:32 AM



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