Digimess Concept Mastech HY3003-3 powersupply test repair
ฝัง
- เผยแพร่เมื่อ 6 ก.พ. 2025
- This DC powersupply is from 2007 from date codes, main problem Volt Amp switches to clean,
i found old bad type of cleaning chemicals in them, so that might explain why my Contact 61 did not work like normal for one of the units, a few LED replaced, minor adjustments, current limit for 5V 3A output was way over 5A, not good. Design is cloned many times, go under many names. if you need to find the schematic search for Mastech HY3010 or HY3020, PCB is called HY068
I did not find the schematic for the 5V add on board so i can not explain how the current limit works.
the two relays switch over points, output voltage :
0.0 - 7.5V
7.3 - 15.0V
14.7 - 21.8V
21.5 - 30.9V
Mains power usage idle at 2 x 0V output 10Watts. and at 2 x 30V = 19 Watts.
---
#teardown
#repair
#powersupply
--
I use auto generated subs, i am sorry there are a few spelling errors,
maybe one day they can do it better..
--
(Thanks to all my Sponsors / Traders / Swappers / Sellers / Buyers, without your support and constant flow of cool items in/out, none of this would be possible)
Thank you!!! I just fixed mine using the schematic and your tip about the grounding point.
that is good to hear
Digimess once was a brand of the German consumer electronics company Grundig.
I have a function generator labeled Grundig Digimess FG100.
No breathtaking features but solidly designed.
I wonder what happened to the T/M branch after Grundig went down.
P.S. obviously a British company bought the name and continues selling T/M equipment
I've never met a psu from this kind of construction with a well working display. And they fail again few time after cleaning, even more faster for unused units. I gived them away, all of them to keep better built unit with current and voltage display.
I have used a different rebrand of one of these (one with separate voltage and current displays) for years and years. Once about 5 years ago i had a fault and just emailed mastech asking for schematics and they sent it to me with no further questions being asked. If i can find them and the email did not ask me not to share them i will put them up somewhere.
I will say with things like this i have rarely had any blocks just emailing about schematics, i believe i have the schematics for every one of my power supplies even the fairly modern switching ones.
thanks a lot mate, i know several of the share sites, i be happy to help, my email is easy to find under my profile
I have seen similar lab PSU's with different names, TTi, Thurlby-Thandar and so on. Quite good for their price range, construction quality not very high, naturally..
Digi-mess haha. Looks like the tektronix PS280 which " appears to be a Goodwill Instruments (Taiwan) / GW Instek OEM product, model GW GPC-3020D"
Give me your thish meter