Gp2X F100 Power Switch


Well-Known Member
Jan 4, 2004
Pennsylvania, USA
Despite the age of my GP2X, I still love using it to play my favorite older games and some of the homebrews as well. But I seem to be having some sort of power problem. I estimate that the GP2X uses about 1.2 watts. I haven't done it in quite a while, but there is a power program that your can run that displays a fire on the screen and writes to the card every 10 minutes or so and it consitently lasted about 5 hours on a freshly charged set of 2500MAH cells. So it's not really taxing the cells with a 500ma draw. Lately I have been having the problem of the machine not wanting to start up, it makes the chime and then switches to the loading device screen and then starts having a quirky screen and fails to boot. It will do this on a freshly charged set of cells.

For a while, I though it was the battery connectors. On the top battery I installed a spring and on the bottom battery I put cardboard behind the (terribly designed) 'leaf' type spring connector to get a tighter fit. I also rubbed on the connecters with aluminum foil to remove any surface defects on the connectors.

I have an old Colecovision and it does the same thing and the fix is to open it up and spray electronics cleaner into the on/off switch. It makes me wonder if my problem is in the switch and not in the battery compartment. Also, once I get it to successfully boot, the red light will sometimes blink on when it's writing to the card. Is the GP2X F100 known to have a problem with the power switch? Is this something worth pursuing? I've never opened it up and I don't have an anti-static wristband handy and I don't want to open it if it's most likely not the problem.

Also, the machine came with 4 batteries and I never bothered with them because I had other ones. Thinking my batteries (despite them being relatively new, less than a year old) might have been damaged in another project, I took the (gp2x branded) batteries out of the box and they are totally dead. I put them in a charge and the charger doesn't even know they are there. Is this normal for NIMH cells? I have Ni-Cad cells that are 20 years old and still work fine. Is there a way to fix them (like how you fix internally shorted Ni-cad cells)? Would it be worth hitting them with 9V (which is what I do with Ni-cads that short or won't hold a charge) to see if they can be brought back to life?

If anyone can help, I would greatly appreciate it.



Certified Guru
Jan 31, 2008
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While there have been issues with the power switch, from everything you've written I'd say it's the batteries. Try a power adaptor (they can be purchased in pretty much any Maplins, RadioShack, Amazon or eBay) for less than $10. The screen going bizarre while trying to boot up is a typical sign that there isn't enough power being supplied. At least that'll confirm one way or another if it's a problem with the switch, batteries or the GP2X dying.
I don't recall the card LED blinking while accessing, but I haven't used my GP2Xs in a long, long time.
As for electro-static wrist strap - that's not necessary. You can earth yourself by touching anything metal - a radiator is good. But you're really unlikely to do any damage as long as you don't poke around the PCB, and even if you do its unlikely to cause harm.
It can be extremely dangerous to overcharge batteries - they can explode, so I wouldn't do anything with them. Just buy brand new high MaH ones rather than trying to bring life back to dead ones. Modern batteries are more efficient than older ones anyway. Get a good set of rechargables.


Still making GP2X and Pandora games, stay tuned!
Jul 11, 2013
Remember to get a proper-spec wall charger if you decide to use one.
None of the rechargeables I used years ago with my GP2X work anymore either, definitely try a new high-capacity 2500mAh+ set.


Dec 20, 2006
This sounds very similar to a problem I had with my f100.
I ran battery tester (name?) and if i'd just nudge the switch there would be a change in the battery metre reading from ~100% to ~80 or something.
In the end I opened it up reheated the solder and sprayed some wd40 into the power switch (contact cleaner would be better) - This solved the issue.  I think there may be some crud/debris on the switch contacts creating random resistance?
I have many other open handhelds now but still think the old GP2X is awesome, it had the best community and buzz.