On occasion I need an autonomous AP, but all I have is a drawer full of lightweights. Here is the process for getting them back to autonomous mode:
(This is from Cisco)
Step 1 The
static IP address of the PC on which your TFTP server software runs should be
between 10.0.0.2 and 10.0.0.30.
Step 2 Make
sure that the PC contains the access point image file (such as c1200-k9w7-tar.122-15.JA.tar
for a 1200 series access point) in the TFTP server folder and that the TFTP
server is activated.
a. Disable any software firewall products, such as Windows firewall,
ZoneAlarm firewall, McAffee firewall, or others.
b. Ensure all Windows files are visible. From Windows Explorer,
click Tools
> Folder Options > View; then uncheck the Hide extensions for
known file types check box.
Step 5 Rename the access point image file in the TFTP server folder to
c1200-k9w7-tar.default for a 1200
series access point, c1130-k9w7-tar.default
for an 1130 series access point, c1240-k9w7-tar.default
for a 1240 series access point, and c1250-k9w7-tar.default
for a 1250 series access point.
Step 9 Hold
the MODE button
until the status LED turns red (approximately 20 to 30 seconds) and then
release.
Step 10 Wait
until the access point reboots, as indicated by all LEDs turning green followed
by the Status LED blinking green.