# OpenIPC Wiki
[Table of Content](../index.md)

CH341A Programmer
-----------------

### Fixing high voltage bug

Early versions, prior ver. 1.7, of the cheap and popular CH341A Mini Programmer
have a nasty bug where voltage levels on data lines remain at 5V despite the
programmer being set to 3.3V with the jumper.

@ddemos1963 came out with an interesting hack to fix the issue in an efficient
and artsy way.

![](../images/hardware-ch341a-hack-1.webp)

Sever the connection between between 5V power line and the CH341A chip.
With a sharp utility knife, cut the trace on the back of the programmer board.

![](../images/hardware-ch341a-hack-3.webp)

Connect 3.3v output leg of the voltage regulator to pin 9 of CH341A IC bridging
it to a corresponding trace at a nerby capacitor.

![](../images/hardware-ch341a-hack-4.webp)

Restore power to the chip re-routing 3.3V voltage from 3v3 pin to pin 28
of CH341A IC through 5V pin connector on the header.

![](../images/hardware-ch341a-hack-5.webp)