Thinkpad X31 won't charge

[KevJr]

Hello everyone.! I own a thinkpad X31 and just recently I believed that the original battery died because my laptop wouldn't charge and when it died the orange charge light would blink about 7 times and then there would be a quick green flash and a pause and tgen it would blink orange again 7 times and the cycle would repeat itself. Lastnight I got my new battery in the mail and I noticed that it wouldn't keep a charge and it eventually died and the charge light started blinking as it did with the original battery. Are there any suggestions on how I could fix this.?

[rkawakami]

Welcome to thinkpads.com!

There's a couple of things that could be wrong with the system. If you are sure that the AC adapter is working correctly (it's able to power the system normally with no battery in place), then the issue is probably on the motherboard.

Unless you have the skills, tools and patience to do component-level repairs of surface mount technology (SMT) parts, the easiest thing to do is to replace the motherboard with a known good unit. Note that this is also probably the most expensive repair option available. My guess is that there is a problem with the battery charging controller IC. I believe that the X31 uses an Analog Devices ADP3806 IC. It could be something like a blown fuse. There could be a loose component that's causing the charger to fail (somewhat a common problem on the earlier T2x systems). Something could have literally "blown up" and you'll see a charred part on the board. Or it could be some "invisible" problem like a defective (or missing) capacitor. With the numerous tiny SMT components on the motherboard, one part could have fallen off and you would never be able to find it, much less figure out where it goes back on.

ref: http://www.analog.com/static/imported-f ... DP3806.pdf (Datasheet for ADP3806)