Lenovo Miix 300 Tablet: Slow Battery Charging with Docking Station After Motherboard Replacement

Hello. I have a Tablet with a docking station, which is basically just writing the topic. Lenovo miix 300 - I replaced the motherboard in it, the previous one had some strange load on one of the three-legged systems (it was heating up). After the board has been replaced, everything works as it should. Touch, display, Windows came in without a problem ... the only problem I have is charging the battery. When connected to the laboratory power supply, it pulls about 0.160A, which is actually quite a small current. The tablet hardly charges even though the 2A charger is connected.
Where to look for the problem? I have the impression that if I bought an original charger (2.1A), it would be OK, but it costs PLN 120, and I would rather make some extra money. I also tried a 3A step-down converter, from the 12V power supply I went down to 5.14, and then the current like blood from the nose ... I will add that I charged the battery on an external charger, and it accepted the current normally ... it took about 2 to fully charge, 5h. [/ U]

niemawolnychnickow wrote:

I have the impression that if I bought an original charger (2.1A) it would be OK

I see you don't trust your lab power supply

niemawolnychnickow wrote:

she had some strange load on one of the three-legged systems (heating up)

Are you talking about a specific layout or about connectors from a detachable keyboard? Specify as precisely as you can what you mean.
This tablet is not charging via USB? Only through the power supply, yes?

Did you change the disc yourself or some service?
Was the disc new or used?

What exactly model do you have?
What are the markings on the motherboard?

Thanks for the answer.

This arrangement is not a problem, I actually mentioned it, I don't know why. I threw the old CD into a box, and replaced it with a completely different one, from a different broken tablet.

It does not charge via USB, as far as I know, the USB here only functions as an OTG. The tablet is charged with a DC charger, with a pin at the end, according to manufacturer 5V 2.1A, I made a 5V 2A charger, I agreed that the charging would be 0.1 ampere less, but I did not know that it would be such a problem :)

I replaced the board myself, but there is no philosophy there ... a few ribbons, two screws and two copper strips as heat sinks .. I plugged everything as Mother Nature commanded, and I doubt that there is a problem here - the charging connector is directly on the motherboard.

@Edit
I do not know the disc marking, it looks like this:
http://www.ebay.com/itm/OEM-LENOVO-MIIX-300-1...NT-64GB-LOGIC-BOARD-MOTHERBOARD-/162172379141

However, the specific designation of the model is: Lenovo Miix 300-10IBY

The motherboard has any markings?
Since the tablet was broken, it may be affected by undefined forces and during the fall it could have caused some damage which manifests itself in this and not another problem.
Did you buy the motherboard itself or the entire broken tablet?

I was buying a broken tablet, ok on the back, even the back was moved because it was nicer. In the front, the digitizer is damaged at the top edge, from the right side seen from the front (on the other side than the plate).

If I soldered directly to the board with the charger, could I rule out a problem with the socket?

So the battery was also so you have two?
Have you checked on both?
On the old disc, despite the element you mentioned, loading was without a problem?

I don't know how many pins you have on the battery, but you can unplug it, connect the charger and check the + and - what voltage is on the board?

Take a photo of the old CD or give its markings

Voltage approx. 4.11 volts on the red pins of the battery connector (from the motherboard side). It seems okay.
I checked two batteries.
I will send the CD markings soon.

Motherboard: M1205BFP-MB-V1.4

Added after 40 [minutes]:

I have plugged in the second battery now, just to be sure ... For 20 minutes, 1% has been charged (and this is progress, because the one on the switched on did not charge at all).
BatteryBar shows charging with 1776mW, is it correct? Theoretically, at 5V it is about 0.3A ... 2A charger, not much, a little, right?

Leave it for longer, then charging the charging current changes, it depends on the battery and the charging system itself. Since the charging voltage on the pins is 4.11, it should be ok.

I was looking for some data only what I was able to find in the attachment.

Alternatively, give the markings from the back cover, you have something like this: 80NR004WCD or 80NR0042PB

I think this battery will be released, it's hard to say ... it will change permanently tomorrow, and I will try to charge it. I changed the charger, I made it from a 3A converter and a 19V power supply for HP.

Today I noticed that the battery is around 3.87V, that's a little bit in total: /
Thanks for the help and the diagram. Have a nice weekend.

gradek83 wrote:

Leave it for longer, then charging the charging current changes, it depends on the battery and the charging system itself. Since the charging voltage on the pins is 4.11, it should be ok.

I was looking for some data only what I was able to find in the attachment.

Alternatively, give the markings from the back cover, you have something like this: 80NR004WCD or 80NR0042PB

Hello
I need m1205bfp-mb-v1.4 schematic full. Please help me

The secret is in the cable.

>>17604620
Hello, I know it's an old thread but if someone can upload the m1205bfp-mb-v1.4 schematic in full, I would be happy about it.
Much thanks.