# UNO BOARD ?.Unknown source **URL:** \ **Category:** 3rd Party Boards\ **Created:** [September 14, 2026, 7:57am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508 "2026-09-14T07:57:28Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 14, 2026, 7:57am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/1 "2026-09-14T07:57:28Z")
I obtained a UNO from a friend and when i tried using it i could not get a com port to suit. On checking Devises it comes up with USB SER. Any hints ? ![UNO 1](https://europe1.discourse-cdn.com/arduino/original/4X/e/f/9/ef912c84a544ac8b6be9263b5da870ad9774d16a.jpeg) ![UNO 2](https://europe1.discourse-cdn.com/arduino/original/4X/3/0/f/30f8b9f3fc676c8fcacfd8d19a4f11be96e1e574.jpeg) ---
**Author:** ![InquisitiveMind](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/inquisitivemind/32/1272398_2.png) [@InquisitiveMind](https://forum.arduino.cc/u/InquisitiveMind)\ **Post date:** [September 14, 2026, 8:28am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/2 "2026-09-14T08:28:23Z")
> [@newby\_pete](#): > > Any hints That's not an original Arduino Uno. It appears to use a **CH340/CH341 USB-to-serial converter** instead of the ATmega16U2 used on an original Uno R3. You most likely need the **WCH CH340/CH341 USB-Serial driver**. Search for: **`WCH CH340 CH341 Windows driver`** or **`CH341SER driver`**. After installing it, the board should appear in Device Manager under **Ports (COM & LPT)** as something like **USB-SERIAL CH340 (COMx)**. If it still doesn't, open the device's **Properties → Details → Hardware Ids** and post the `VID_xxxx&PID_xxxx` value here. That will identify the USB chip exactly. ---
**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 14, 2026, 9:51am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/3 "2026-09-14T09:51:21Z")
> [@newby\_pete](#): > > On checking Devises it comes up with USB SER. I assume you're using Windows. You can check the VID and PID by opening the device in Windows device manager, select the _Details_ tab and select _Hardware Ids_. For the mentioned CH340 it should look like ![image](https://europe1.discourse-cdn.com/arduino/original/4X/9/a/8/9a8c0febc8301a8ee19158c6b06bede03ceda62e.png) If you have problems, the VID and PID can help us to help you. The serial-to-USB converter (IC closest to the USB port) does not seem to have visible markings on it. That can cause upload problems in which case [UNO stopped working after having worked for years - #24 by ptillisch](https://forum.arduino.cc/t/uno-stopped-working-after-having-worked-for-years/1427477/24) might provide a solution. > [@newby\_pete](#): > > I obtained a UNO from a friend Can your friend provide details? E.g. did it work when he was using it? On the same operating system (Windows, Linux, Mac)? PS Apologiesd at @InquisitiveMind, I see that he posted the VID/PID story already. ---
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 14, 2026, 11:13am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/4 "2026-09-14T11:13:49Z")
Hi. i have unistalled and reinstalled the CH340 driver and still not working. Under properties- drivers not installed(code 26). When update driver- none found. It looks like a bin job. ---
**Author:** ![InquisitiveMind](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/inquisitivemind/32/1272398_2.png) [@InquisitiveMind](https://forum.arduino.cc/u/InquisitiveMind)\ **Post date:** [September 14, 2026, 12:11pm UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/5 "2026-09-14T12:11:30Z")
> [@newby\_pete](#): > > It looks like a bin job Before you bin it, please post the **VID and PID that sterretje asked for in post #2 + #3**. Reinstalling the CH340 driver won't help if the USB chip isn't actually a CH340. ---
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 15, 2026, 3:37am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/6 "2026-09-15T03:37:34Z")
Hi. I tried everything with no joy. I tried using windows 10 and it works. It must not like windows 7. Thanks for your suggestions. ---
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 15, 2026, 3:46am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/7 "2026-09-15T03:46:24Z")
The VID 0x0834, PID 0x5740 as shown on Windows 10. ---
**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 15, 2026, 4:28am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/8 "2026-09-15T04:28:41Z")
Where did you find the VID/PID? In Windows 7 or in Windows 10? That VID/PID is for a STM IC; see [Virtual COM Port — USB 0483:5740 — DeviceHunt](https://devicehunt.com/view/type/usb/vendor/0483/device/5740). You can try to find a driver: [windows driver for vid 0483 pid 5740 at DuckDuckGo](https://duckduckgo.com/?t=ffab&q=windows+driver+for+vid+0483+pid+5740&ia=web). From the [first result](https://www.driverguide.com/driver/company/STMicroelectronics/index.html) ![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/5/0/a502267e23357bab7df1506745fefbf1c6467e9f.png) So maybe you can install a driver using the information on that page. ---
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 16, 2026, 5:52am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/9 "2026-09-16T05:52:50Z")
Found using Windows 10. I will look into those drivers. Thanks ---
**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 16, 2026, 5:58am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/10 "2026-09-16T05:58:09Z")
You should be able to see which driver is used in Windows 10; might give an indication what you need. ---
**Author:** ![newby\_pete](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/newby_pete/32/1126914_2.png) [@newby\_pete](https://forum.arduino.cc/u/newby_pete)\ **Post date:** [September 16, 2026, 6:00am UTC](https://forum.arduino.cc/t/uno-board-unknown-source/1459508/11 "2026-09-16T06:00:25Z")
I will check on that. Thank you.