A31 battery will not charge or power laptop.

[photon_wrangler]

My A31 laptop will not charge it's battery or run off battery power, however it runs fine when used with the power supply. I have reset the bios to default and that did not improve the situation. The battery is definitely not the problem as I have charged and tested it with a different computer, and it holds a good charge. I have been trying to identify bad components in the vicinity of the battery socket. Does anyone know of any weaknesses in the battery charging circuitry in this particular model?

There was another thing, this laptop's original power adapter's voltage when being operated would fluctuate +-4 volts when connected to a multimeter. Maybe this is the cause of this problem and perhaps it could provide some clues on how to fix it. I have also tested the SMB fuses near the battery socket and they appear to have continuity. If anyone has any ideas or leads on fixing this problem then please tell me anything could help.

I was concerned this capacitor in the image could be damaged, but I don't know how to identify it's type.
http://s30.photobucket.com/albums/c307/ ... ture18.jpg
This part seemed odd to me, it's a copy of the plug for the battery, what is it's purpose?
http://s30.photobucket.com/albums/c307/ ... ture21.jpg

[AMATX]

If you've tested the A31 battery in another laptop, then try that laptop's battery in the A31 and see what happens. Should be interchangeable.

[rkawakami]

re: picture18.jpg The capacitor appears to be a 22uF 20V polarized (i.e., electrolytic) unit. This is based upon the numbers on top of the "can" and the "+" on the board (next to C747). Regarding the battery terminals, I'm not sure where it is on the motherboard but maybe it's for the Ultrabay?

[photon_wrangler]

Could a bad adapter like the one I described cause a fuse to blow on the motherboard and therefore cause the charging circuit to not receive power? The adapter was acting very strange with fluctuations in voltage and amperage. If a fuse did blow, are the fuses labeled with F<num> for identification? I also see some components labeled fl<num> and I am unsure what they are.

[rkawakami]

re: your adapter. Sure, that's within the realm of possibility. It could also be due to other component(s) that's either been electrically damaged or simply disconnected from the board. For example, T23 boards have a problem with keeping a couple of the inductors attached to the board. The usual problem is caused by two on the bottom side of the board and you end up with a nearly dead system. There's another inductor on the top side next to the battery terminals. When that one works loose, the battery fails to charge.

Yes, fuses are identified by the F<num> designation on the board. I can't say that all of them are labelled but many of them are. If you look in the lower left corner of your picture21.jpg image, that white block with the silver endcaps is a 10A fuse that probably protects the Ultrabay battery. Based upon what I've seen on T23 motherboards, there should also be a smaller fuse next to those battery terminals which looks like the one labelled F9 in this photo:

http://www.kawakami-ca.com/ibm_t2x/main_fuses.jpg
(You can also see the same kind of 22uF 20V capacitor in my photo. The inductor is the black "square" above the capacitor and has 150 N21 printed on it. To the left of the inductor is the ADP3806 chip. That is the heart of the battery charging circuit.)

FL<num> designations are typically filters; essentially a coil of wire. As such, you can test them for continuity just like a fuse (0 ohms = good). If you do find a filter that reads infinite resistance (i.e., open), then you have the problem of figuring out the correct value for a replacement. They are too small to have any kind of markings so the usual advice is to find the same kind of motherboard and swap the part.

[photon_wrangler]

Well, I tested 20 fuses on the motherboard and all of them had continuity. You have mentioned inductors coming loose, but they all look to be mounted quite well. Is it possible that this is a bios problem? Keep in mind I reset the bios to factory defaults. I also upgraded the bios and EC firmware to the newest release. I am pulling my hair out over here and I feel my possibilities for fixing this board are dwindling.

[rkawakami]

I don't know that a update made to either the BIOS or EC that went wrong would render your system unable to be powered by the battery or prevent the battery from being charged. However, if your problem occurred immediately after said update(s) and nothing else was changed, then I guess that's something to consider. However, I doubt that you could now rollback the BIOS or EC since one of the requirements to do these updates is having a fully charged battery connected and the system being able to see it.

I assume that when you have the battery attached to the A31 and the AC adapter connected, the battery LED on the LCD bezel is not lit? If so, then I would think that there's something wrong with the battery input or charging circuit. If you can't find anything visibly wrong like what is circled in black in this photo:

http://www.kawakami-ca.com/ibm_t2x/let.jpg

then it may be hard to pinpoint the problem. If it were me and I could not find any obviously smoked part and that all of the fuses that I could find are checking out okay, then I would trash the motherboard and get a replacement. Even if I did manage to find a blown fuse and replace it, I'd still worry that whatever killed the fuse in the first place is still present on the board. Since you say that the original AC adapter was varying in voltage prior to the system developing this issue, I would suspect that was the source of the problem. It's possible that the overvoltage was enough to kill the battery/charging circuit, yet allows the rest of the system to work normally.

And as a last-chance suggestion, I would say try pulling all of the socketed hardware out of the system (except the CPU) and see if that changes anything. Remove all memory, Ultrabay devices, hard drive, MiniPCI card, CDCs (modem, ethernet, Bluetooth), etc. and try powering up with just the battery. If it does miraculously power up and you get the 1-3-3-1 "missing memory" beep code, then one of the things you just took out of the system is the real problem. Odds are if it does power on, then I'd bet that the MiniPCI card is bad. I've seen some really weird system problems with malfunctioning MiniPCI cards.

[photon_wrangler]

Actually when I have the battery inserted and the ac power on, the battery light is lit. I was able to perform the bios and ec upgrade without any issues. The computer detects the charge currently in the battery and reports it correctly in Ubuntu. I also removed every piece of hardware and connected the battery, yet the problem remains. The battery will not charge or power the computer. It seems very strange. There is one visible piece of damage that I found on what I believe is an inductor, it is marked with an ellipse and the number 2. The components surrounded by the rectangle are what I think are resistors, however when tested with the multimeter they are registering as zero ohms. One other thing, would a malfunctioning IC, inductor, or capacitor raise in temperature while the computer is powered on?

http://s30.photobucket.com/albums/c307/ ... oblems.jpg

[rkawakami]

Group of parts indicated in the area you have designated as "1" are slightly bigger than normal resistors, even though there appears to be an R525 next to one. If they are reading near 0 ohms then they may actually be extremely low resistance resistors, say somewhere less than 0.5 ohm. Those are used in some of the power supply controllers as current sensors. If you are familiar with some circuit schematics, then check out this:

http://datasheets.maxim-ic.com/en/ds/MA ... AX1635.pdf

Resistors R1 and R2 on page 8 is what's relevant here. If the controller detects excessive current at power up, then it basically shuts down to prevent damage. This might be what is causing your problem. I can't tell what or how bad the damage is to the inductor but I would bet it has to do with one of the main voltage supplies in the system.

[photon_wrangler]

Well, I think I am going to call it on this one. I'll use the rest of the laptop parts for parts and maybe find a new board.