[Elecraft] Test serial-to-USB converter

[Rick WA6NHC]

A multitude of USB 'sins' can often be cured by a complete powering down 
of the computer, including pulling the power cord (on desktops) and 
removing the battery (laptops).  A soft reboot doesn't always reset the 
hardware but 10+ seconds of zero power to them usually does.  In this 
condition, the only power in the computer is the RTC battery.

All this test costs is time and most of the time, it works here.

Then make sure that the OS hasn't assigned it/them a new port value 
(com2 instead of com5).  You may have to use Device Manager in Windoze 
to force it to accepting the value you want.

This is why when I built the shack computer, I went back to using real 
serial ports, which are far more stable.

Good luck.

Rick nhc


On 7/18/2016 4:05 PM, Don Wilhelm wrote:
> Jan,
>
> The best way to test a USB to serial converter is by substitution with 
> a known good one, or by substitution of a known good working serial 
> device connected to the questionable converter cable.
>
> Yes, a power surge or a lightning event can damage serial interfaces 
> as well as USB interfaces.
>
> Since your USB ports on the computer seem to work, borrow a known good 
> USB to serial converter and try it out - preferably one with an FTDI 
> chipset.
>
> If you have any other devices that use a serial COM port interface, 
> see if they work with your USB to serial adapter - if so, the adapter 
> is probably OK, but remember that in the event of a power surge, 
> multiple failures are possible even though in normal troubleshooting 
> we assume only a single failure.
>
> You can test the USB to serial converter with a 'scope and an RS-232 
> breakout box, but you have to know the proper RS-232 levels to 
> understand what is happening.  A null modem loopback cable can be 
> helpful if you have to proper driving software application for that 
> testing.  I did that during my years of PC modem testing, but that was 
> more than 30 years ago and the software ran under DOS - not helpful now.
>
> 73,
> Don W3FPR
>
> On 7/18/2016 6:36 PM, Jan Ditzian wrote:
>> I have a K3 that lost communication with my computer. It uses an 
>> Elecraft serial-to-USB converter and cable.  This probably happened 
>> during a known power surge.  I also lost communication to my MDS 
>> rotor, which uses a built-in USB cable, which I believe may also be a 
>> serial-to-USB arrangement.  I checked things out a bit, and I can 
>> tell that my USB ports all seem to work.  I also tried the K3 with 
>> another computer and was unable to communicate with it.  However, I 
>> also tried a direct serial-to-serial cable from the K3 to the first 
>> computer, which has a serial port, and was also unable to 
>> communicate.  I am now unsure of the location of the problem.  I am 
>> willing to go with whatever works.
>>
>
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