If you have display brightness problems with your expensive handheld multimeter VOLTCRAFT VC890, here is a solution for it!
A few month ago the OLED display of my not often used multimeter (bought ~2015 on conrad.de) was getting darker and darker. Now I can't see anything on the display anymore. After little research I found a forum thread in which the people discuss exactly my problem. But no one has found a compatible display, yet. And the Conrad support has not responded to this day.
So I decided to search for displays on alibaba.com. Previously I disassembled my multimeter and removed the display, it's very easy only few screws! After few pages of OLED displays I found a very very similar looking one with same dimensions for 36USD = 31€. So ... let's purchase and wait for it :)
The package arrived after a month. I quickly installed it and ... cool it works :D The display color is now white.
1) Display Mode: Passive Matrix
2) Display Color: Monochrome (white)
3) Drive Duty: 1/64 Duty
4) Wide viewing angel: >160 degree
5) Brightness: 100 cd/m2
6) Dark Room Contrast: >2000:1
7) Operating Temp.: -40---85°C
2. Mechanical Specifications
1) Number of Pixels: 128 × 64
2) Panel Size: 73(W) x 41.86(H) x 1.82(T)(mm)
3) Active Area: 61.41(W) × 30.69(H) (mm)
4) Pixel Pitch: 0.48 × 0.48 (mm)
5) Pixel Size: 0.45 × 0.45 (mm)
From user Bluebrain
To make the display brighter and crank up the voltage from 13V to 15V (which is within the specs of the display), install a 100k resistor between GND and the step-up regulator feedback pin as shown:
Bernhard (Dienstag, 23 November 2021 10:47)
Hi Otello, many thanks for your research and the effort, to spread the information. I've bought the display as well and after some minor modifications on the frame, it worked fine in my VC890. Thanks a lot, best regards, Bernhard