Univolt DT-2020 F.G. - / Seg Display Damaged - Page 1
Forum section: electronics / repair

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 26, 2015, 08:03:18 pm
content: Hi;I've got a F.G. DT-2020 from univolt, but some segment of digit 3 of the display are damaged. I already desoldered the display and tested. I've googled but i can't find anywhere. Can somebody help me.Also, if someone has the service manual for this F.G. i would appreciate!Photos BellowThank You!

author: pmcouto
author_rank: Unknown
timestamp: November 26, 2015, 09:10:45 pm
content: Hi,That’s a custom display – Unless you find a donor instrument, forget about finding a replacement part…

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 26, 2015, 09:14:42 pm
content: Quote from: pmcouto on November 26, 2015, 09:10:45 pmI know, but i have to try! ( Concordo contigo, mas pode ser que por aqui alguém tenha, ou conheça quem tenha. Tenho de tentar! )

author: pmcouto
author_rank: Unknown
timestamp: November 26, 2015, 09:21:12 pm
content: Boa sorte!

author: Gyro
author_rank: Super Contributor
timestamp: November 26, 2015, 09:27:17 pm
content: It is a custom display, but that doesn't mean you can't have a reasonable chance of fixing it.Those old displays have led dies on the PCB with white plastic frame and overlay on top. If you separate the plastic from the PCB you might well be able to replace the dies with small (0603) leds soldered to the tracks. You'll need to replace them all because of the low brightness of the originals - It depends how important repairing it is to you!Alternatively you could maybe just keep end pieces with the indicators and bodge in some standard 7 segment displays for the digits.Could be a fun project...P.S. Don't try peeling the overlay film off the front - the silk-screen ink will stick to the frame and flake off.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 26, 2015, 09:49:45 pm
content: Quote from: Gyro on November 26, 2015, 09:27:17 pmHummm..... That's an interesting thing to do..... Maybe i will try that.I will wait a little more, just to know if someone have one, we never know!

author: Gyro
author_rank: Super Contributor
timestamp: November 26, 2015, 10:30:14 pm
content: Yes, certainly something to leave until the display has no further value to you! (Edit: sorry, thought you were pretty much at that stage, maybe not though!) The led dies will each have a bond wire on top.The only thing difficult about that display is that it has indicators with legends at the ends, aside from that you can maybe make a complete physical replacement with a bit of matrix board, some 7 seg displays, leds and header strips - there are enough pins that it doesn't look multiplexed.The firsts thing to do is work out its pinout using a meter on diode test range (if the segments are bright enough). or 5V power supply and series resistor. Hopefully you will find a common connection, either common anode or cathode, and a pin for each segment / led, and comprehensible gaps for the dead ones.For the indicators you could maybe use rub down lettering on the front panel, rectangular LEDs with lettering,... or if really confident by that stage, the ends of the existing frame!