Path: utzoo!attcan!uunet!cs.utexas.edu!know!sdd.hp.com!hp-pcd!hpcvra!prestonb
From: prestonb@hpcvra.CV.HP.COM (Preston Brown)
Newsgroups: comp.sys.handhelds
Subject: Re: Melting 48 Display
Message-ID: <25590065@hpcvra.CV.HP.COM>
Date: 15 Oct 90 16:56:48 GMT
References: <9095@helios.TAMU.EDU>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 14


The melting is caused by messing up the drive voltages going to
the display.  The system control registers start at #00100h and
you are poking invalid codes into the display voltage control
registers.  The effect is caused by putting a large DC voltage
across the pixels in the display.  The LCD material responds
well to the low AC voltage normally used but a large DC voltage
produces the effect you see.

If you leave the DC voltage on the display for long periods it
may cause a reliability problem.  The [ON]-C corrects the control
registers and restores the proper voltages.

Preston