HP Forum Archive 14

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HP 21 changing batteries Message #1 Posted by raze on 22 Jan 2004, 6:30 p.m. Hello all, I need help please, I have an almost mint condition HP 21. IT is in perfect physical order, but I cannot open the battery door. I tried to use a knife to open it, but I don't want to break the the battery door. So, does anybody know how to open it? (I tried pressing and slide it down and nothing) Any help with me greatly appreciated.

Re: HP 21 changing batteries Message #2 Posted by hugh on 22 Jan 2004, 7:47 p.m., in response to message #1 by raze i had this problem. dont use a knife! in the end i opened it using the heel of one hand and some force whilst holding it in the other hand. it helps to yell a lot too :-) incidently, i found a neat way to open the battery case by making one small cut. http://voidware.com/calcs/woodstock_repairs.htm [aside: i have to finish the page which will cover a feature of fixing the keyboard]

Re: HP 21 changing batteries Message #3 Posted by David Smith on 22 Jan 2004, 8:50 p.m., in response to message #1 by raze If you have a lot of trouble opening the battery compartment it almost always means the battery pack has spewed massive amounts of corrosion in there... You can usually slide the pack down a millimeter or so then lever it out with a fairly wide thinn bladed screwdriver. Be careful not to slip or gouge the case.

Re: HP 21 changing batteries Message #4 Posted by Larry Corrado on 22 Jan 2004, 8:59 p.m., in response to message #3 by David Smith I have often had this problem with my Woodstocks, even without corrosion. I've had good success with a 1" wide aluminum ruler that I used to push against the protruding ridge on the bottom of the pack (pushing in the direction of the arrow.) As David mentioned, this moves the pack forward a bit, and then the screwdriver can be wedged in place at the bottom of the pack, to be used as a lever. Ditto on being careful not to gouge the case. Good luck. Larry

Re: HP 21 changing batteries Message #5 Posted by David Smith on 23 Jan 2004, 1:05 p.m., in response to message #3 by David Smith The adventureous out there in HPLAND may also want to try soaking the machine in a glass of warm water to disolve the battery barf. You then would need to open up the case, rinse everything with distilled water a few times, shake as much water out of the keyboard, etc and let everything dry for a couple of days. Also whenever a machine gets this corroded you will probably have to clean some of the key contacts.

Re: HP 21 changing batteries Message #6 Posted by Michael Meyer on 23 Jan 2004, 1:43 p.m., in response to message #5 by David Smith My only concern about soaking the whole thing is the LED display module, which isn't waterproof in this model. The plastic magnifier is staked onto the LED module, but getting water inside of it can't be good.... I'm sure there's lots of spares out there, though. Michael

Re: HP 21 changing batteries Message #7 Posted by David Smith on 24 Jan 2004, 11:19 a.m., in response to message #6 by Michael Meyer And lots of them with a dead dot/segment/digit/etc... I have bathed a few of the display modules before without any ill effects. I usually dry things in a low oven (<150 F) overnight.

Re: HP 21 changing batteries Message #8 Posted by Randy Sloyer on 24 Jan 2004, 12:15 p.m., in response to message #7 by David Smith Prying from the back gets ugly, so when I get a siezed woodstock, I remove the top feet and screws, push on the charger pins, pop the front off and then deal with the crusties inside from the front of the logic board. I have found that to be the easiest way to free a battery being held hostage. Just be careful when it pops apart not to bend the keboard connections.

Re: HP 21 changing batteries Message #9 Posted by Veli-Pekka Nousiainen on 24 Jan 2004, 8:18 p.m., in response to message #8 by Randy Sloyer If you do bend the display connector pins (a fork-like constuct) however you can open them up witha small crewdriver [VPN]

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