HP432 Repair Part 2 - It's not all good news
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- Опубліковано 4 лип 2024
- This is a quick part 2 video in the series I'm doing on repairing the HP 432A. We'll take a look at whether the A1 board actually works and at the proposed replacement component.
- Наука та технологія
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why don't you use permanent clamps when measuring the resistance of the potentiometer? That's quite cumbersome and in the end confusing how you're doing that measurement.
That's a great point - I was expecting to just make a measurement at one end and then the other and call it done - I wasn't expecting that the potentiometer was also bad - Should have stopped and set up for a better test.
BTW After your comment, I did do that so I could see how the potentiometer reacted while turning it (just in case there was some update to the unit that enabled them to use a lower value pot) - It rises to its max value about 4-5 turns in and then sits there for a few turns before dropping back down to around 1K.
Just to add some more detail for those wondering - The potentiometer in the donor unit is HP part number 2100-2849 which, according to the manual I have, was added starting with the prefix 919.
In any case, it is supposed to be a wire wound 50K 5% 1.5W potentiometer - This one clearly isn't.