开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育

Re: HP 3403C True RMS Voltmeter display fault


 

开云体育

Yes, Ed, I know exactly what you mean regarding the orange leadless tantalum caps. ?Sprague used to make them, and they told us that the orange material prevented them from printing the value, voltage, etc on them. ?A real bummer because many times the wrong voltage rating parts were installed and blew up! ?I stopped designing boards with them for that reason. ?Life’s too short to have exploding caps in your products. ?Too short not to intentionally blow them up on the bench, though! ?LOL!??

Jim Ford?
Laguna Hills, California, USA?


On Mar 3, 2025, at 10:59?AM, Joel Setton via groups.io <setton@...> wrote:

?
Hi AArnaud,
?
Congratulations for the successful repair, and for having saved another valuable HP instrument from the scrap heap !
My conclusion is somewhat identical to my initial thoughts : start by checking the "usual suspects", supply voltages and clocks.
The obvious next step for your 3403C is a complete performance check and recalibration, if you have the appropriate equipment. If you're lucky, first adjusting the calibration in DC-only voltage mode may bring the instrument back into full compliance, which of course would be great news.
After that it'll be time for another instrument repair project, and for more fun !
Cheers,
Joe;

Join [email protected] to automatically receive all group messages.