Edgardo, Two possibilities: Cathode poisoning or bad tantalum caps. I'm not sure if "cathode poisoning" is really the correct term for this effect, but it's similar. There have been a number of tutorials out there about rejuvenating VF displays.
The one I have direct experience with is bad caps. We bought an HP 6612C power supply with a bad display for an automated test setup. It's basically the same VF display used in a lot of the instruments from that family. We didn't really need the display because it was for an automated setup, but I wanted to fix it anyway. When I removed the display board I found that it had 3 or 4 large tantalum caps on one edge. One of the caps was toasted a crispy brown color instead of the usual yellow. After replacing that cap the display came right back to life and has been working fine for a couple of years, now. BTW: those display and button boards are a bit of a trick to remove. They're slide in from the side under some "L" shaped plastic features in the case front. There are instructions in the service manual for dealing with them. -John -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Edgardo Molina Sent: Friday, November 02, 2012 11:24 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP-53132A Faded and flickering display Dear Group, Good morning! I just got my first HP-53132A frequency counter and Prologix GPIB-USB converter. Now I can do some measurements and I am excited about it. Everything looks promising. Condition of the instrument on the outside is like new, controls responsive and no fading in lettering at the buttons. Connectors are not worn or damaged, original connectors. The unit has been tested and works OK, probably not with adequate calibration but that is not an issue now, I can always calibrate it later. What worries me is the display. Even though being an Agilent built unit, it has probably more hours on it than a seldom used HP built unit. The flourescent display is fading, not all the digits show consistent illumination levels. The left-most digits show some flickering at some of their segments. It is readable in the end, but I am terribly disappointed about it. Does anybody know if there is a cure for this? Or should I start saving for a better unit. I am not afraid of the screwdriver or the soldering iron if someones suggests a display overhaul. Thank you! Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
