Display 3478A - Page 1
Forum section: electronics / repair

author: hnjmkl
author_rank: Regular Contributor
timestamp: November 16, 2022, 09:32:39 am
content: In an attempt to rotate the LCD (DSP1) of my 3478A it went KO, P / N 5061-1166. On YT someone managed to replace the 3457A LCD with different displays, even nixie, do you know a feasible project for this intervention? Is the 3478A's LCD different from the 3457A? In appearance they are identical but in the 3457A Service manual I did not find the P / N of the display.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 16, 2022, 11:58:28 am
content: I think one of the most comprehensive discussions about replacing HP3478A displays is at the following thread:https://www.eevblog.com/forum/projects/led-display-for-hp-3457a-multimeter-i-did-it-)It starts with an LED replacement but there is also mention of using small OLED graphical displays.(edit) found the other OLED thread.https://www.eevblog.com/forum/testgear/hp3548-hp3457-oled-display/(edit) fixed URL

author: ledtester
author_rank: Super Contributor
timestamp: November 16, 2022, 12:26:17 pm
content: Quote from: rsjsouza on November 16, 2022, 11:58:28 amThe first link has a paren at the end which doesn't get included as part of the URL by the forum's editor.Here's a working link:https://www.eevblog.com/forum/projects/led-display-for-hp-3457a-multimeter-i-did-it-%29/

author: M0HZH
author_rank: Regular Contributor
timestamp: November 16, 2022, 01:59:58 pm
content: I used a display from a cheap HP 3488A Switch/Control Unit to restore a HP 5385A Frequency Counter and did some reasearch at the time.Many of the HP gear of the era use the same displays, there are 3 revisions "groups" where displays are compatible with eachother (so 3478A would work with a 6622A display) but no proof that they're compatible between groups (for example 3478A with 3488A display).LCD PN: 5061-5212HP 3478AHP 6622AHP 6630A/BLCD PN: 5181-2813, 5063-2305 or 5083-3473HP 3457AHP 3468AHP 3488AHP 3852AHP 5384AHP 5385AHP 5386AHP 6624AHP 6645AHP 6674ALCD PN: 5065-7075unknown models, after 1995I'd still get a cheap 3488A unit off eBay and try its display out on yours, not much to lose.Some of my pics / comments from when I did the swap:https://twitter.com/YO9IRF/status/1339663054053789696

author: sagias
author_rank: Newbie
timestamp: March 09, 2024, 07:04:33 am
content: Tested oled on 3478

author: ZGoode
author_rank: Frequent Contributor
timestamp: April 01, 2024, 05:27:53 pm
content: Quote from: sagias on March 09, 2024, 07:04:33 amSagias,That is awesome! I'm trying to do something similar to what you have done. Are you able to post any of the schematics/code for your work?

author: Miti
author_rank: Super Contributor
timestamp: April 01, 2024, 07:13:46 pm
content: Quote from: ZGoode on April 01, 2024, 05:27:53 pmThe second link in the second post is what you need.

author: kawal
author_rank: Frequent Contributor
timestamp: August 26, 2024, 12:14:45 pm
content: Quote from: M0HZH on November 16, 2022, 01:59:58 pmI have a few 3852A that came with 5061-5212 displays Rev A displays. these have triangular symbols on the bottom.I did take a display from 3457A model 5181-2813 and placed it in the 3852A and it works.I made a few OLED displays that work in the 3457A but the same OLED display will not work in the 3852A. Very strange.