Pravir Chawdhry's notes on using the HP iPAQ h5550

WLAN problem

Problem: The iPAQ WLAN does not turn via:
Start -> IPAQ wireless -> WLAN (click): even though WLAN icon turns orange-to-green, the Orange WLAN LED does not turn on.

Solution: Take out the battery for a minute, then put it back in and do a soft reset.

Credit: Solved with the Help of official HP/iPAQ customer support via online chat within minutes.

Re-Charging problem with flat battery (and screen freezes on switch on)

Given: a flat battery, recharging directly from the AC adapter did not work as expected. Possible cause: the WLAN was set as ON (with Skype running) when last used. The authentication was set to PIN or fingerprint with fingerprint as the option used in the last login.

Problem: The iPAQ freezes up after turning on.

iPAQ starts with the authentication screen (set for finger print recognition in this case), but freezes up at this screen. It would not responded to anything: scan finger, screen taps, try to turn power off; not even attempts to do soft reset or hard reset. ... The screen also did not go in powersave mode, but finally it drained the battery and the iPAQ 'died'.

After this it refused to recharge through the AC adapter - even when the adaptor was applied for 24 hours. No attempts to soft or hard reset would work. Taking out the battery pack and replacing it made no difference.


Place the iPAQ in the cradle - connected the cradle to the AC mains charger as well as to a PC (both USB and serial leads were connected to the PC).

After 24 hours, the soft reset worked.
Authentication with fingerprint was needed (as set before it died). Worked fine. Asked user to calibrate screen, reset clock, etc. as expected. The power level now was 100% on the back up battery and 84% on the main battery. The Charge LED now flashed indicating further charging was in progress.

Question: While on the cradle, did it recharge from the USB port or the mains power?

Some tests

General comment

Based on the above two problems, it would appear that there is some undesirable interaction between the WLAN and the rest of iPAQ software, this causes the iPAQ to hang occasionally when it is turned on.

Conclusion: Turn WLAN off and close Skype before switching off iPAQ; to avoid problems.

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Latest update 29 November 2005
© Pravir Chawdhry ( and G. Q. Maguire Jr., KTH/IMIT

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