No bootload from Linux laptop

Arduino:1.8.13 (Linux), Tarjeta:"Arduino Uno"

El Sketch usa 1636 bytes (5%) del espacio de almacenamiento de programa. El máximo es 32256 bytes.
Las variables Globales usan 202 bytes (9%) de la memoria dinámica, dejando 1846 bytes para las variables locales. El máximo es 2048 bytes.

ioctl("TIOCMSET"): Invalid argument
ioctl("TIOCMSET"): Invalid argument //after this msg, about 10 secs before the next

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00
Problema subiendo a la placa. Visita http://www.arduino.cc/en/Guide/Troubleshooting#upload
para sugerencias.

Error al configurar los parámetros del puerto serial: 9.600 N 8 1
........

Computer: Lenovo ThinkPad T410s, with Linux Mint 20
Card: generic Uno clone. Works & uploads perfectly with other laptops, like
Sony Vaio and hp14 (also running Linux Mint)

  • I ran the arduino-linux-setup.sh script; all req'd groups are in place;
  • I have tried the reset button before upload, to no avail;
  • The board is identified in Tools as "Uno"; port as /dev/ttyUSB0;
  • I even tried the trick "sudo chmod 777 /dev/ttyUSB0"; doesn't help (it works
    for the Sony Vaio)
  • Tried the downgrade to 1.8.7, as somebody suggested; did not help
  • The laptop has 2 USB ports; both work perfectly (with mouse, printer & scanner)

I'a at a loss about what else to try. Does anyone know about incompatibilities
with a Lenovo T410s? I will really appreciate any suggestions!

You say "bootload". Are you doing a standard "Upload" or are you doing a Tools > Burn Bootloader?

Sorry, I actually meant "uploading". No "Burn Bootloader"

Does the problem happen if you try uploading to the Uno with no external circuitry, shields, etc. connected to the Uno. The external circuitry can interfere with the upload sometimes.

The Uno is running bare, with nothing attached to it. The sketch is also the simplest, like Blink.