…I was having issues with the calibration process, so I will use that instead.
With Transistor Testers that were previously in use,
I go into the menu and select “Self Test” which works its way through several different screens, first with “probes shorted,” then with “probes isolated,” and finally with a film capacitor connected to pins 1-3. I use a 1.0uF capacitor for this. Don’t rush it by pressing the button to move on to the next screen. It will advance all by itself after each section finishes. I had to practice this several times before I was patient enough to wait and let it proceed at its own pace.
In particular it appears that capacitor ESR results are more accurate after performing this full menu-driven “self test” with the 1.0uF film capacitor connected to 1-3 when the display message calls for it.
I’ve also used the faster self-test with probes shorted before pressing power button. But this “fast self-test” by itself
didn’t permanently shut off the
“not calibrated” message. It was only after the longer self-test (from the menu) that the
“not calibrated” message disappeared permanently.
I discovered this “not calibrated” issue with an unmodified “GM328 color-kit” tester running the original Chinese factory firmware it came with. This firmware displays “1.12k” but I suspect the Chinese modified it. Unfortunately its ATmega328P is locked.
Among several transistor testers in my workshop I use this one the most. I’ve had only one issue with it: I accidentally toasted its SRV05-4 overvoltage protector with a charged capacitor. The tester worked well again after removing the failed SRV05-4 except it began showing the
“not calibrated” message. I observed no damage to the ATmega328P or any other parts. But I did need to run the full menu-driven self test after that incident in order to clear the “not calibrated” condition.