I bought another Shanze 232 cable, and again the port wouldn’t open. (Actually, the one I’d bought before also wouldn’t open, but I’d forgotten.)
This time I went back and forth with Shanze’s Taobao customer service for ages. They insisted that I send the cable back for a replacement. First, I didn’t want the hassle; second, I was almost certain this wasn’t something a replacement would fix. I decided to dig into exactly why this cable couldn’t open the port.
I won’t post the screenshots of that exchange. They said it definitely uses the CH340 solution and told me to try another CH340 cable. Anyway, there was no productive communication.
Even though the port wouldn’t open, data still had to be flowing over the USB link, so I gave a USB hardware packet sniffer a try.
That capture exposed the problem right away: the chip’s handshake IN packet reads “USB2.0 SER”?
So is that really what it is? I tried a very expensive isolated serial adapter, also based on the CH340 solution, and they definitely use solid components. One look showed something was off: that adapter reads “USB SERIAL”.
Then I searched online for a driver for “USB2.0 SER” and found this.
After flashing that driver, this piece-of-junk Shanze cable actually opened the serial port!
Of course, their enable packets and configuration packets are also different. I saved the screenshots but won’t post them. That’s exactly why my original driver couldn’t open the port.
Notice that the driver that works with this cable is from 2009. Combined with their claim that they’ve now “switched” to the CH340 solution, it’s fair to assume they got a batch of ancient stock chips and used them to make this batch of cables. I last bought one a year ago, so they’ve been using these stock chips for at least a year.
This kind of thing wreaks havoc on your computer’s driver environment and causes very serious problems. The main issue is that both old and new drivers show up as CH340 (even CH341), so you simply can’t tell whether the USB-to-serial adapter is broken, the hardware itself is broken, or the serial monitoring software has a bug. It adds a whole new dimension to troubleshooting, and it’s really infuriating.
August 27, 2025: I don’t know what changed in some system update, but that driver and the cable are now completely dead.