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Posts: 15
Registered: ‎08-16-2011
Location: Sweden
Message 1 of 7 (560 Views)

Battery not charging despite being reported as good and as charging

Hi,

 

I have an X220 Tablet that's about 3 and a half years old -- so unfortunately just out of warranty -- and I'm having battery/charging problems. A few months ago the original 6-cell battery that came with the laptop died: Power Manager reported it as dead and needing replacing. It had had 500-something cycles, so it seemed reasonable. I went ahead and bought a new 6-cell battery from Lenovo, the 67+, and then my system was fine again. But one day a few weeks ago this battery suddenly stopped charging. Power Manager reported that "The battery is in good condition", and it was reported as "Status: Charging", but it was not actually charging and was instead very slowly discharging its way to 0%. Something suspicious is perhaps that PM reported "Current: 0.00 A".

 

I thought it might be the battery, so I got another one, but that has exactly the same issue -- now I have two batteries, each discharged completely and with no way to charge them.

 

Charging doesn't happen regardless of whether the computer is on or off, or whether I'm in Windows (7) or Linux.

 

I checked the AC adapter/charger with a multimeter and it is reporting 20V as it's supposed to, so I guess that's okay. Plus, the laptop runs fine on just the AC adapter, even if it's a little bit slower (which I gather is due to it being 65W rather than 90W).

 

The only slightly unusual thing I can remember from the day charging stopped functioning is that I was using the 'always on' USB port to charge my phone. But I've done that many times and never had a problem, and I've tried changing the settings for that both through Windows and the BIOS.

 

So, what gives? How can I diagnose what the actual problem is? Should I check the pins that the battery slots into under the computer when the AC adapter is in? Any other ideas?

 

It would be a great shame if this machine stopped functioning as a laptop just because it's not charging the batteries.

 

Most grateful for any help!

 

 

 

Community Moderator
Posts: 6,580
Registered: ‎01-01-2010
Location: US
Message 2 of 7 (541 Views)

Re: Battery not charging despite being reported as good and as charging

It is hard for me to be certain without seeing it, and Sweden is a long way from San Francisco. The symptom point to a blown fuse or power transistor (mosfet). Either can cause your problem, and usually require motherboard replacement. If nothing was going on when the problem started, (no power failure, lightning storm, failure of power adapter, tripping over the cord) I would guess mosfet. Some shops can repair fuses, but they require fairly good soldering equipment. I have had much poorer luck fixing mosfets, because usually, more than one chip is bad. You might be able to find a motherboard for a reasonable price. I have one for sale on eBay for under $100, but international shipping is expensive and you might do better locally. Send me a private message if you wish to discuss


I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

I am not an employee or agent of Lenovo.
Fanfold Paper
Posts: 15
Registered: ‎08-16-2011
Location: Sweden
Message 3 of 7 (535 Views)

Re: Battery not charging despite being reported as good and as charging

Thanks for the reply! Is there some kind of schematic of the motherboard or whatever I would see if I were to take the back off the laptop? E.g. to show me what I need to do to get to the fuse so that I could test that?

 

I'm hoping one could do that without special equipment. I have some basic soldering equipment, but perhaps that won't be enough even if it's just the fuse?

 

I think I did drop the AC adapter on the day charging started failing, possibly while it was plugged in to power and the laptop (but I'm not sure about the latter). Could that cause the fuse to blow? Or the signal part of the AC adapter to somehow malfunction? (I don't have another adapter to test right now unfortunately, but will probably buy a 90W one soon anyway to be able to run at full speed without a battery.)

 

 

Community Moderator
Posts: 6,580
Registered: ‎01-01-2010
Location: US
Message 4 of 7 (524 Views)

Re: Battery not charging despite being reported as good and as charging

[ Edited ]

Minimum soldering equipment would be a temperature-controlled rework station and a quartz preheater. There are no schematics for anyone other than Lenovo engineering. I've never seen one.. I'm not sure where the fuse is on x220 tablet, but they are usually near the LCD connector on either side of the board. (usually under stick-on black plastic) The fuses are extremely fast burning, so any sort of minor surge can cause the problem. I would guess that 90W and no battery would still run at a reduced speed. Fuses tend to be the little parts with 2 connections that are not the resistors or capacitors. Resistors are black, and capacitors are beige. Often, backlight fuses are 1.4mm long and 3-amp. The solder used is lead-free so it has a very high melting point.



I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

I am not an employee or agent of Lenovo.
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Posts: 15
Registered: ‎08-16-2011
Location: Sweden
Message 5 of 7 (506 Views)

Re: Battery not charging despite being reported as good and as charging

Thanks for all this info, richk -- it's very useful. I guess you repair these? Shame I'm not in SF!

 

I took a look at some of the motherboards on ebay, and I'm not sure to what extent they are interchangable. My machine is a 4299-2PG which has mobile broadband -- do I need a particular motherboard for that? Or does the mobile broadband adapter just plug in somewhere on the motherboard?

 

In any case it seems like it would be pretty wasteful to swap a whole motherboard if it's just a faulty fuse. Do you know if it's reasonably straightforward/safe to open up the machine and get to the actual fuse, just to take a look? The motherboards I saw on ebay seem to be covered in some kind of black plastic -- can one peel that back and put it back on easily? I'm guessing the fuse is under that somewhere.

 

Do you, or does anyone else, know what happens with the charging circuitry if one gets a battery slice? In this case the 19+. I got the impression that this has its own charger, so that one can charge it directly from the AC adapter. With this plugged in, would this slice charge the main battery too, or would a faulty fuse or mosfet on the motherboard still hamper the main battery charging?

 

Thanks!

 

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Posts: 15
Registered: ‎08-16-2011
Location: Sweden
Message 6 of 7 (505 Views)

Re: Battery not charging despite being reported as good and as charging

p.s. The 90W AC adapter and no battery running at reduced speed -- is that because of the particular problem that I'm having, or do you mean that in general?
Community Moderator
Posts: 6,580
Registered: ‎01-01-2010
Location: US
Message 7 of 7 (487 Views)

Re: Battery not charging despite being reported as good and as charging

[ Edited ]

All the boards have a WWAN slot. Any of them will work in your machine.  You have i5-2520 CPU. It is a very common CPU. (Note: The CPU is soldered, and comes with the board.)  I have never run an x220 without a battery, but in general, thinkpads run at reduced speed without a battery. I have no experience with slice batteries, although I think I have one around here somewhere. The plastic comes off. I put it on waxed paper so I can reapply it. It is not simple to find the fuse and to figure out which fuse it is. There are lots of fuses. (more than 10 and fewer than 100) They range in length from about 1.2mm to about 3mm long. Rather than saying I repair these, I would say I try to repair these. I am often successful, but not always. It is easy to dislodge another part. It is easier on larger boards, like T and W series. Also, after replacement of the fuse, sometimes it doesn't work. I assume that means something else was damaged or that I screwed something up. I will add that Lenovo considers fuse problems non-repairable. Dealers and service centers swap the boards, although they send them away and I assume that many or most come back as serviceable used parts or remanufactured parts.



I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

I am not an employee or agent of Lenovo.
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