Strange laptop battery power issues?

[dtech12]

Hey guys, I am having a very strange Issue when it comes to my "Dell M5010". I have received this laptop as a gift from a previous owner because of the power issues. Normally I am very good when it comes to troubleshooting hardware issues on computers because of my experience and Google skills. (I have googled this for a few days and I still can't figure it out.) Except I have no idea what is going on. Also this is my first post on this forum so sorry if I don't have the best formatting. So here goes:

My Dell M5010 will shut off immediately when the AC power cable is disconnected from the laptop. However, I am certain that this is not a battery issue since I have purchased another battery and the problem still remains. (batteries charge fine.) Also, If I charge the batteries to 70 - 100% and then disconnect the power cable the laptop will run off of the battery until it reaches around 70% and will immediately shut off. Again, if I disconnect the AC power cable from the laptop below 70 - 100% it will shut off immediately. I cannot turn on the laptop whether or not the battery is charged to 70 - 100% (Power button just flickers on for a brief second.)

I have:

1. Tested both Windows and Linux, both OS do the same thing. Messed with countless power settings, no luck.

2. Reseated the RAM and reset the CMOS battery, no luck.

3. Updated the BIOS to the latest version, no luck.

4. Checked the battery pins, they're fine.

5. Cleaned the fans, not overheating.

Chances are some power management circuit on the motherboard is fried and will need to replace the motherboard, and I'm probably in denial. Unfortunately, I am a student so it will be hard to get the money to replace the motherboard so if you guys have any ideas on what could be going on I will greatly appreciate it!

 

[thx1138v2]

This will take a bit of time but very little money. Disassemble the laptop and remove the motherboard. At each step where you disconnect something electrical (ribbon cable, etc.) inspect it closely for dirty pins and/or socket particularly looking for evidence of something spilled like soda, coffee or whatever. Inspect any daughter boards the same way. If you find such evidence clean it with 90% rubbing alcohol and put it aside for later reassembly.

Also look for bad capacitors on the motherboard and any other circuit boards you expose. Try to isolate the power management circuit and determine if there are any physical signs of circuit damage like bad capacitors and/or overheated resistors, etc. Your diagnosis sounds correct.

Once you have the motherboard removed look in the exposed parts of the case for the same thing and clean it up if you find any. If it looks like a particular spill leaked into or under any other parts, go through the same procedure with those parts.

If you find this kind of problem and are able to clean everything up put it back together and try it again.

If not, at least you are at the point where you need to be to replace the motherboard. The only cost to this point would be the rubbing alcohol and some Q-tips.

I can't tell you the number of times I have taken computers apart and put them back together with no changes other than cleaning and re-seating the connectors and they magically work again. So you might want to try that even if you don't find problems.

 

[dtech12]

This will take a bit of time but very little money. Disassemble the laptop and remove the motherboard. At each step where you disconnect something electrical (ribbon cable, etc.) inspect it closely for dirty pins and/or socket particularly looking for evidence of something spilled like soda, coffee or whatever. Inspect any daughter boards the same way. If you find such evidence clean it with 90% rubbing alcohol and put it aside for later reassembly.

Also look for bad capacitors on the motherboard and any other circuit boards you expose. Try to isolate the power management circuit and determine if there are any physical signs of circuit damage like bad capacitors and/or overheated resistors, etc. Your diagnosis sounds correct.

Once you have the motherboard removed look in the exposed parts of the case for the same thing and clean it up if you find any. If it looks like a particular spill leaked into or under any other parts, go through the same procedure with those parts.

If you find this kind of problem and are able to clean everything up put it back together and try it again.

If not, at least you are at the point where you need to be to replace the motherboard. The only cost to this point would be the rubbing alcohol and some Q-tips.

I can't tell you the number of times I have taken computers apart and put them back together with no changes other than cleaning and re-seating the connectors and they magically work again. So you might want to try that even if you don't find problems.

Okay, I will try that out tomorrow! I'll tell you how it goes, thanks!