I bought used Samsung SCX-3405FW printer but can't connect to Wi fi due to wrong password. Kindly assist

10 year old printer, with super tiny old LCD on front.
the manual covers that, did you read that first, no 2 printers made have the same steps and rule
in generic form sure, but not the same in practice
can I guess you are at home, Not told
and have computer do you , not told
and have and OS on that computer not told (windows 10)_ but is a wild wild guess me....
do you own your own wifi router? or does your ISP own it and be locked down by them. IDK, only you know that

first off if at home,
do you have a cell phone or computer that that can test your home wifi>? yes/no
if yes, does it work? that?
yes good, not set the printer up the same way, with SSID ,WPA2 and your wifi passphase
I guess you lost your wifi credentials,? that It AT HOME.

IF ALL THINGS FAIL FOR WIFI AT HOME THEN ASK (your self or hubby or? dad) WHO OWNS IT NEXT.
IF YOU OWN IT SET THE PASSWORDS IN THE WIFI ROUTER YOUR SELF (RTM READ THE MANUAL IN IT)
OR IF NOT Yours but is owned by the ISP, internent service provider ask them
or even look on the rear of the router for a tag saying there are your CREDENTIALS

some printers must be reset.
if some are in USB mode the WIFI option is dead. so must be reset.
then read the manual how.https://www.manualslib.com/manual/201800...

read page 156
if wps method is not allowed on your router , you just do it by hand.
most modern routers do not allow PIN method now, its unsafe this way.

the manu's on this printer are complex but what you need is Wi-Fi Direct
not usb, not ethernet that both work better to any PC.
Wi-Fi Direct
there is in the same menu's wifi on and off, so turn that on first.

I found the manual way to set up wifi, on page 162, and 163
USING THE MENU BUTTOn
it tells you this
Before starting, you will need to know the network name (SSID) of your wireless
network and the network key if it is encrypted. This information was set when
the access point (or wireless router) was installed. If you do not know about your
wireless environment, please ask the person who set up your network
that means you need to know YOUR WIFI CREDENTIALS
press
menu
network
wlan
press wizard
it asks for wifi key and you tell it that.
or not wizard
Custom: In this mode, users can give or edit manually their own SSID
, or choose the security option in detail.. this always works, doing it MANUALLY
https://www.manualslib.com/manual/201800... 10 year old printer, with super tiny old LCD on front. the manual covers that, did you read that first, no 2 printers made have the same steps and rule in generic form sure, but not the same in practice can I guess you are at home, Not told and have computer do you , not told and have and OS on that computer not told (windows 10)_ but is a wild wild guess me.... do you own your own wifi router? or does your ISP own it and be locked down by them. IDK, only you know that first off if at home, do you have a cell phone or computer that that can test your home wifi>? yes/no if yes, does it work? that? yes good, not set the printer up the same way, with SSID ,WPA2 and your wifi passphase I guess you lost your wifi credentials,? that It AT HOME. IF ALL THINGS FAIL FOR WIFI AT HOME THEN ASK (your self or hubby or? dad) WHO OWNS IT NEXT. IF YOU OWN IT SET THE PASSWORDS IN THE WIFI ROUTER YOUR SELF (RTM READ THE MANUAL IN IT) OR IF NOT Yours but is owned by the ISP, internent service provider ask them or even look on the rear of the router for a tag saying there are your CREDENTIALS some printers must be reset. if some are in USB mode the WIFI option is dead. so must be reset. then read the manual how. https://www.manualslib.com/manual/201800/Samsung-Scx-3405.html?page=156#manual read page 156 if wps method is not allowed on your router , you just do it by hand. most modern routers do not allow PIN method now, its unsafe this way. the manu's on this printer are complex but what you need is Wi-Fi Direct not usb, not ethernet that both work better to any PC. Wi-Fi Direct there is in the same menu's wifi on and off, so turn that on first. I found the manual way to set up wifi, on page 162, and 163 USING THE MENU BUTTOn it tells you this Before starting, you will need to know the network name (SSID) of your wireless network and the network key if it is encrypted. This information was set when the access point (or wireless router) was installed. If you do not know about your wireless environment, please ask the person who set up your network that means you need to know YOUR WIFI CREDENTIALS press menu network wlan press wizard it asks for wifi key and you tell it that. or not wizard Custom: In this mode, users can give or edit manually their own SSID , or choose the security option in detail.. this always works, doing it MANUALLY https://www.manualslib.com/manual/201800/Samsung-Scx-3405.html?page=162#manual

the used printer is using the old owners PW and will never work, like that. (but usb does and ethernet wired)
learn to RTM
learn to do page 162, manual way, using only YOUR credentials.
SSID name
wpa2
wifi pass phrase, AKA password. the used printer is using the old owners PW and will never work, like that. (but usb does and ethernet wired) learn to RTM learn to do page 162, manual way, using only YOUR credentials. SSID name wpa2 wifi pass phrase, AKA password.