Tech2 – RS-232 Loopback not connected

We also bought a Tech2 device. Our supplier Cathy from Hippotech from Shenzhen Hippo Tech Co., Ltd. sent us fairly quickly the device. After a few days we received the boxed “car diagnostics sample unit”. Playing around with the it all seemed to work. However connecting it to the TIS2000 was a problem. The Tech2 failed to pass the RS232 loop back test every time. We reported this instantly to Cathy Wong (a.k.a. “cathy11005” and “”) and here is where it went downhill.

Connected the RJ45 RS-232 loopback plug and the 25-pin loopback plug into the Tech2:


This is the result. Bummer!


The communications between Hippotech and us became dreadful and after weeks and numerous emails eventually we received only lame excuses from Cathy and vast moments of silence. Up till now not a single solution was mentioned by Cathy.

Now we are stuck with a non-communicating Tech2.

So if you like to buy a Tech2 be sure to think twice before you order at Cathy Wong at Hippo Technology Co. LTD, see other contact details to avoid.

Just sharing our experiences…



Now we have to take fate in our own hand and try to fix the problem. So searched the internet for a while and i stumbled upon this article at “diy-tech2” blog from “lol_ka” at which described in minimalism style that the RS-232 chip could be flaky, translation:

“And here is how to fix the error rs232 and if its not there then an error connecting to the computer. Any chip series max232 sop, often instead max232 is max 202, the same principle, and they differ by the presence of protection. They cost a penny. Also it will not be superfluous to solder the connector pins around the max232.”

2014 by lol_ka

This told me that the most likely suspect is the RS-232 chip. This led me to search for a replacement. MAX232D Transciever MAX 232 Texas SMD was easily tracked down on eBay. So i bought a couple (as they happen to sold as a couple, i have received 4 SMD ICs. The soldering of the SMD component can be tricky so some experience is very handy.


After the replacement of the SMD component the Tech2 reported “Passed” on the RS-232 Self Test. So, project Tech2-RS232 has been completed successfully.




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3 Responses to Tech2 – RS-232 Loopback not connected

  1. Anonymous says:

    May I suggest you to disassemble the Tech 2 (which is very easy) and check the RS232 connector soldering ? All the connectors seem to be manually soldered in those chinese clones and sometimes only partially done…

    Another way would be to check or rebuilt a fresh new RS232 loopback as you can find here

    Good luck !

  2. Rusnak-COBRA says:

    So, did you try something with that TECH2? is it working now, with new chip, or replaced by Cathy? Or any further communication?
    BTW, you don’t need WIS communication for many things, what you want to do?

    • Berry says:

      Actually i fixed the problem myself by replacing the MAX232. Cathy was communicative as a rock.

      What i wanted with the RS232 at that time… i just wanted to work!

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