# Troubleshoting ZK-4KX V3 It displays incorrect information **URL:** \ **Category:** General Electronics\ **Created:** [September 14, 2026, 1:07am UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489 "2026-09-14T01:07:41Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![pejman1977](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/pejman1977/32/1227633_2.png) [@pejman1977](https://forum.arduino.cc/u/pejman1977)\ **Post date:** [September 14, 2026, 1:07am UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489/1 "2026-09-14T01:07:41Z")
I have a buck-boost module of this exact model. For the past few days, all the displayed readings have been incorrect. It shows higher-than-actual values ​​for both input and output voltages, even when adjustments are made. How can I reset this module or re-flash its original firmware? I would appreciate some guidance from those with more experience. There is space on the board for a dedicated serial communication setup, but I am unsure if a specific file is required for it—and if so, where I can download it. I searched extensively, but the only guides available are in Russian—and they are completely false, incorrect, or intended to mislead. Many thanks to all the friends and everyone who helps those with less experience. Please forgive me if my English isn't very good. I wish you all the best.😘 ---
**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\ **Post date:** [September 14, 2026, 1:30am UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489/2 "2026-09-14T01:30:38Z")
> [@pejman1977](#): > > For the past few days, all the displayed readings have been incorrect. I do not have a clue as to what you have, so I will assume you are using an Arduino Uno R3. What are you using to measure the voltages to determine that they are off? What voltage reference are you using for your voltage measurements? I assume you are using the Arduino's 5V supply as the reference. Posting an annotated schematic will help us help you. Be sure to show all connections and note any wire over 25 cm/10". Also show how everything is powered and provide links to the technical information for the hardware items, such as the SEPIC (buck-boost) converter. Just as an FYI, the Arduino Uno R3 normally uses its 5V supply (AVCC) as the reference for the A/D converter. If you are using the default ADC reference, a lower VCC can cause the ADC reading to increase, provided the voltage being measured does not decrease proportionally with VCC. The 10-bit ADC approximately calculates: ADC = 1023 \* VIN / VREF With the default reference: VREF = VCC For example, if the input remains at 2.50V: VCC = 5.00V ADC = 512 VCC = 4.75V ADC = 538 VCC = 4.50V ADC = 568 Therefore, a 10% drop in VCC will produce approximately an 11% increase in the ADC reading for a fixed input voltage. If the voltage being measured is derived directly from the same VCC, however, both VIN and VREF may change together and the ADC reading may remain approximately the same. Hopefully this helps. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [September 14, 2026, 11:12am UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489/3 "2026-09-14T11:12:28Z")
> [@pejman1977](#): > > all the displayed readings have been incorrect. How do you know this. Do you have an accurate DMM? ---
**Author:** ![sterretje](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sterretje/32/391294_2.png) [@sterretje](https://forum.arduino.cc/u/sterretje)\ **Post date:** [September 30, 2026, 9:11am UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489/4 "2026-09-30T09:11:38Z")
A post was merged into an existing topic: [How to use Arduino with ZK-5KX dc-dc buck boost converter](https://forum.arduino.cc/t/how-to-use-arduino-with-zk-5kx-dc-dc-buck-boost-converter/1461545/2) ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [September 30, 2026, 5:09pm UTC](https://forum.arduino.cc/t/troubleshoting-zk-4kx-v3-it-displays-incorrect-information/1459489/5 "2026-09-30T17:09:03Z")
This seems to be a common issue without resolution... [Troubleshoot ZK-4KX BUCK-BOOST calibration](https://forum.arduino.cc/t/troubleshoot-zk-4kx-buck-boost-calibration/1393848/)