Good diagnosis USB electronics are bottom of the barrel, the standard itself is ill-defined and it is pressed into far too many uses that it shouldn't be. Serial ports are a perfect example, anyone working with SoC boards that use +3v serial ports has run into the joy of multiple serial port cables some that work on some boards others that don't, some that work on some computers others that don't.....
Ted -----Original Message----- From: PLUG <[email protected]> On Behalf Of Keith Lofstrom Sent: Monday, March 9, 2026 9:49 PM To: [email protected] Subject: [PLUG] Failed KVM switch (fault tree then swap) Recently, I've had problems with "distant text echos" while editing text documents with web page screen editors. Insert in a line of text, and 5% of the time, some of the characters are inserted in a different line as well. Weird. I won't go through the whole debug sequence ... I tried easy stuff first; a different keyboard, different mouse, different software, remote login, etc. Remote login worked. My first clue. What I could not easily test was a different USB+DVI Keyboard/Video/Mouse switch (I drive two different computers with it). So I purchased (eBay) a used ioGEAR GCS932UB "identical" to the switch I've used for decades. After moving 16 cables to the new one ... IT WORKS! The old one goes to scrap recycle; a re-purposing scrapper like Free Geek might test it incompletely and give someone else a debug headache. I post this not to brag, but suggest a few more debug and replacement ideas for the rest of you. Electronics can do the darndest things. And I post this to the main list, rather than PLUG-TALK, because an adept software geek may spend way too much time looking for a software problem, rather than a weird hardware problem. I'd rather help them with hardware problems, and they can help me compile "hello.c". :-) Keith L. -- Keith Lofstrom [email protected]
