Nokia 1661 Security Code | Phone/Device Issues and Features | Consumer forum

I had this same problem, but I called the SO rep.

She told me that it's now a known defect with this phone. She basically asked me to "power cycle" the phone.

Meaning to turn off the phone, take out the battery, wait 15mins. Put in the battery, wait 15mins, then turn on the phone for 15 mins. Then eventually the code 12345 will work. I did that for the entire afternoon and finally got it to unlock.

Today another scary "defect" showed up. The phone was reporting NO SIM CARD. I restarted the phone a few times and finally it was able to detect the sim card, but all my phone settings including time and date were wiped.

I feel that this Nokia 1661 phone is not very reliable. So many problems for a phone with so little features.

A similar thing just happened to me. I used the phone yesterday and shut if off for the night, but when I tried turning it back on today the phone (Nokia 1661) would not respond at all -- just a black screen. I had to remove the battery, re-insert the battery, and then the phone would turn on; however, I was then prompted for a security code. 1-2-3-4-5 did the trick, but now all of my settings are gone. I also can no longer select a new ringtone. When I try, the phone turns off, turns back on, and I need to re-enter the security code again. I got the phone free when I purchased a $100 airtime voucher, so I really shouldn't complain -- but c'mon... ... ... If the phone has this kind of widespead malfuction, you'd think Nokia would recall all of them.

same thing happened to my nokia 1661 when i turn it on this morning
fortunately found this thread

For some reason the phone ask me to enter security code every time i turn it on, and all the call history information are erased. Also I have been wondering why I missed so many calls in the past few weeks - perhaps it was because the phone wasn't even ringing. It seems that there are a lot of problems with this phone.

just wana extend my thanks to nancam for your post helped. for a while, i thought of pawning this 1661 nokia away.

...i've been using this nokia 1661 for 11 months(start feb2010 and going), so far no problem and then
one day, when i check to see if i have some messages on my phone, the screen asked for a "security code" and what can i say, i entered 1234, did not work, i entered my PIN, also did not work. i entered a lot of number and other combination i know off. all did not work. since you can just plug in some number, i just keep on plugging. no maximum limit of try anyway. then i gave up. this phone is bricked i assume. so i googled some info about this and it seems, this is a common problem for this (sorry) crappy but goody cheap nokia 1661 phone.

my first try actually did not work. what i did is that i removed the battery from the phone for one night. then i put back the battery, and when it asked for security code, i entered, 12345 = does not work. so i review again what possibly did i miss on this forum. and this is what i did miss (from nancams post):

"do what nancam said".... then
....
– press and hold POWER button for at least 10 seconds
– replace battery and cover
– turn phone ON
– do not touch keyboard for at least 15 minutes
– default 12345 code will now work

so it did work. after waiting for about 20 minutes i put on 12345 and now i am IN.
i turned off my phone. turn it again, and it asked again a security code. i put 12345 and i am in.
i then set the security level (from the phone settings) to off so i dont need to plug that 12345 everytime i turn it on. so far so good, im back on using my old phone. so what basically happened on my phone after this "security code" brohaha?

well, all call lists are gone. (dialed numbers, missed calls, received calls, etc) but phonebook and messages data are still there.