Putty hangs when connected to 3502i

[Steven B]

Let me start by saying this is for my homelab and I bought the 3502i off of ebay, i'm trying to factory reset it for use in my personal networking setup for study.

As a premise, I've never had issues with my Cisco 3750-x, 3850, or Juniper srx320 security appliance when connecting to the console line via usb to rj45 serial through Putty as a terminal emulator. However, today I started to attempt to factory reset a 3502i aironet wireless ap and it prints its own info just fine in the terminal emulator, but when I try to enter something it takes 30+ key presses and makes it impossible for me to navigate even passed the login prompt.

Right now after holding down the button to factory reset the ap I'm stuck at "ap:" and nothing I type is actually displayed which presents a real problem with configuring the ap. Again no other devices have this issue, just the ap. What could be the issue?

my settings are standard 9600 baud 8 data bits no parity 1 stop bit no flow control.

I'm on windows 11 latest Putty release 79.

The switch for example works fine as seen above with the same settings

[balaji.bandi]

have you tried :

use no flow control.

[Steven B]

I have tried that to no avail 

[balaji.bandi]

at this not sure what went wrong, as it mentioned the IP address 10.0.0.1 connect to network and try to access using GUI or SSH see if you can access it.

follow below config guide :

https://www.cisco.com/c/en/us/td/docs/wireless/access_point/15-3-3/configuration/guide/cg15-3-3/cg15-3-3-chap4-first.html

[Steven B]

So I tried several things including that guide and nothing has worked but I was able to ping it after enacting a DHCP server to assign it an address. The default 10.0.0.1 address was not pingable however I blocked every address except 10.0.0.3 for DHCP and plugged it in to my switch, then it accepted the address which was pingable but only from a normal boot not from recovery mode. So then I scanned it with nmap using the -p 1-65535 flag and the only TWO ports that were open were 37540 and 37550 which means ssh, telnet, ftp etc was blocked. so I tried an informal approach and attempted to use ports 37540 & 37550 with telnet, ftp and http anyways down below is the result for the http but the results were similar regardless of what method I used.

thats alright though I think with DHCP working I may be able to just buy a cheap WLC and attempt to access it from there.

[balaji.bandi]

i will try different cable or different PC see if that fix the console access.

if you like you can try converting AP to autonomous AP (if that is your requirement)

https://blog.router-switch.com/2014/12/how-to-convert-a-cisco-3502i-ap-to-operate-in-an-autonomous-mode/

[Rich R · Accepted solution]

I've posted this on numerous other threads but here goes again.  This is 99% probably a problem with your cable.  Cisco APs are very fussy about console cable, even if it works fine with other Cisco devices.
I use https://www.amazon.co.uk/gp/product/B07MYQPYKR but any similar cable will work.
Generally speaking cables with genuine FTDI chipset work well, but other chipsets and counterfeit FTDI based cables often don't.
Always check product reviews before ordering to make sure somebody has tested the specific product with Cisco APs and make sure the cable you get sent is what was described (sellers sometimes substitute other products without telling you).
Even with a working cable I find they sometimes just stop receiving anything as if going to sleep (USB power saving?) and pressing a key will wake it up.

[Steven B]

Alright, I'll give it a try, I've pretty much exhausted every other possibility and that's the last thing I haven't tried, cable coming in tomorrow, FTDI usb to serial rj45, hopefully that's it and I can finally get these APs up and running.

[balaji.bandi]

sure good luck. keep us posted, as we suspect the cable only here.

[Steven B]

It was indeed the FTDI chipset. Works perfectly now, thank you both Rich & Balaji! 

[balaji.bandi]

glad all good.