620lx replacement adapter voltage?

Picked up an HP620LX palmtop. To use one of these universal ac adapters, does anyone know the voltage it should supply?

3? 4.5? 6? 7.5? 9? or 12?





Congraduations on finding the HP-620LX. Although a little slow, still a fun unit to play with. As to the AC adapter, I found the following info about a "house brand" substitute ac adapter. 12V at 1.5 amp. See following link:


If you didn't get manuals with it, then the following links may be of some help:

The 620 Zone web page:


The HP Palmtopper Page - Most of this is about the HP200lx, but it does include some 620lx items also:


Have Fun with it.



I've got it plugged in at 12V of DC (but it's not 1.5 Amps - only 1/3 of that).

The "orange" charge light is now on. I'll give it a few minutes and then see if it will turn on.


It'll take a while (few hours) to turn the light into green,

at least with that 'weak' AC adapter;-)





Normally it will power on,

but if not, you could try a reset.

The (red) reset button is behind the

small door where the backup cell also sits.

You can press that reset button with

the stylus for a second.


Tried that. Nothing. :-(

When in the dock, it will glow "orange" or if I wiggle the adapter cord, it will sometimes be blinking "green".

I have the universal AC adapter set to 12.5V, but it is providing 500ma, not the 1.5 amps the original adapter gave.



0.5 amp should be enough to operate the 620lx. I can't remember if the docking station directly puts the adapter power to the coaxial adapter connector on the 620 or if it's transfering the power through the multi-pin connector. I would try removing the unit from the docking station and pluging the ac adapter directly into the unit.

I would also try the following:

1. Remove the Lithium battery and check to see if show's any effect from the charging. If after plugged in for several hours, the battery voltage is still low, then the battery is probally done for. You'll need a new battery.

2. If battery seems to be accepting the charge, and unit still won't power up, remove both battery and backup battery and let unit set for a day or two. Then reinstall and see if it will power up. I'm assuming that the backup batter is good? But even with a dead or missing backup battery the unit should power up and then give you a message saying "replace backup battery".

3. Last resort - remove main lithium battery. Plug in the adapter and see if it powers up. this "should" be safe, but I'm not 100% sure that it won't damage the unit. That's why I say last resort.

4. If you do Item (3) - and all is well, then check the unit's battery contacts to see if the adapter is apply voltage to them.

Good luck,



A small addition:

I think I remember that my old 620LX

sometimes stuck in the same way.

Somewhere I read (maybe in the manual?)

that removing both batteries and then pressing

the reset pin for 10 or 30 seconds would do s.t.

like a hard reset.

At least worth a try.



Sorry for the Star Trek line.

I think the 620LX is dead.

Took both batteries out for 45 minutes. Pressed the red reset pin for 30 seconds, etc.


When in the dock, it will display an orange light which indicates it should be charging. Sometimes, it will show a solid green light, which indicates charged, and sometimes it flashes green (which isn't defined in the manual) :-)

In no circumstance can I get it to turn on.

I think she goes back to the seller. Oh well. Thanks for the efforts, folks!


Sorry for the Star Trek like answer,

but to get on-topic again:

Have you checked if the WinCE

module is plugged correctly?

It's a small pcb which sits in a slot

inside the main battery compartment.

When the batt is removed, you'll

see a strip of black film,

optionally covered by an aluminium shield.

If there's no plug-in module,

the unit is just a no-brainer;-)

In that case I could offer a fully

working 660LX module with 32MB RAM,

which is left from a 660LX with bad display.

If there is a module, maybe it doesn't sit correctly.

To verify this, just pull it out carefully,

and reinsert it. You'll know when it's fully inserted,

because it's edge is aligned with the slot edge.

Just another idea.


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