Hello,
at the end I was? able to resurrect my X5105 !? I? explain you how .
As described in previous post trying to update the firmware my X5105 remained in "waiting mode" after having erased completely the firmware.
I had bought from Xiegu.eu? the "original" blu plastic cable, but there was no connectoin between PC and Radio. In particular there was no letter C? in the monitor?
of Teraterm. Problem was that inside this cable there is a FTDI clone, and? recent drivers from FTDI are disabling the chip. I was? asking Xiegu. Eu for? help and they sent me a new? cable for free. This time was a FTDI chip cable original, model TTL-232R-3VR-AJ? , USB to TTL Serial 3.3 V.? But also this? cable didn't work . No letter C, confirming the communication and? no sign of activity. My feeling is that even if this cable has surely an original FTDI Chip working with the latest VCP drivers, there is an issue of? contact with the 3.5 mm audio jack that is too short. I've read somewhere that this jack for X5105 has to be a bit longer as the photo hereunder

In the meantime the person that sold me the X5105 ( I had bought second hand)? found the cable that he utilzed to update the firmware in the past and sent it to me.
I connected the cable and ...... the PC? ? read the cable as Prolific chip,? but a clone? again. In particular in the device? windows manager in the COM port? there was written? "PL03HXA? phased out? since 2012 . Please contact your? supplier" . I was expecting something like that because the Prolific clone? chip issue is known.
An English dealer? , Sinotel, is publishing a small guide? with instructions to workaround? ???
In particular it's explained that it needs to have an old? driver 3.3.2.102? dated 24.09.2008 and is offering a link to download. But the link is wrong, and on his download page? there are many prolific drivers? but not? that one .? I found it on the web? here???.? ? After having installed and updated the COM port? with this driver , I had immediatley? signs? of? connection, and the letter? C? appeared on the monitor. I tried to upload the firmare and it worked but the uploading process failed at 24%? every? time. I? don't? know? why. I made several attempts without? success and the % of loading? became everytime smaller? and smaller. I supposed that was an issue connected with the battery. I left the power? cable inserted? for? 1 hour in "waiting" mode . Tried again.... and? success , I? was able to upload the firmware. !
It was a nightmare . It's unbelevable? why Xiegu is not able to offer? cables? that works.? I hope that this? story? could help somebody else that could run in the same trouble. I? wish to thank all of you for the suggestions you gave me . In particular thanks to??Jim? ?G4EQX