Windows with putty via USB serial cable to Linux serial port - output ok, input isn't

"Not saying this is your case, but in the past I used the same cable to connect a laptop to some working machines. Didn't work ... whatever we did, it didn't work. The cable was ok though.
Then we tried a different brand of cable (everything else, the same) ... worked!

Never found out what was wrong ... but heard from other people having the same problem.
This is not very helpful, just saying ..."