Lenovo Thinkpad E15 board NM-D011 power

[warsztat]

Hi, Lenovo Thinkpad E15, board NM-D011 problem with power in USB-C.

The problem is the low voltages on the gates of the transistors as shown in the pic1.
The slightly conductive transistors got very hot until they broke the connection.
Transistors need 4.5V at the gates to conduct, so the voltage should be around 25V.
It seems that the fault is in the transistor control system, in the photo TP565994, I found a pdf TPS65994 which is probably the same system in a different housing.
If I understood the pdf correctly, the system is programmable, so buying a new one without software will not be successful. Please correct me if I misunderstood it.
TP565994 works with UB9 CAT24C256 memory, so it's possible that there is some configuration in it. I wonder if reprogramming this memory wouldn't solve the problem. I'd like to try a file for it.
Regards.

MOD Edit - link to schematic https://www.badcaps.net/forum/showthread.php?t=106574

https://cdn.badcaps-static.com/pdfs/...ca08711b51.pdf

[mon2]

Re: Lenovo Thinkpad E15 board NM-D011 power

These are N-channel mosfets so yes, the gate should be HIGHER than the voltage being passed between source/drain pins to enable.

Respectively, the voltage should not be passing if the gate voltage is so low at 4v5.

Remove all power. Remove fuse F6101 for now.

Power up again. What is the voltage to ground of the 2nd dcin mosfet at F6101 pcb pads? It should be ~0 volts.

If not, remove all power, meter in resistance mode.

Measure the resistance across:

Source (1-2-3) & drain (5-6-7-8)
Source (1-2-3) & gate (4)
Gate (4) & Drain (5-6-7-8)

Post each measurement. Do these checks for each of the DCin mosfets. Suspecting that the 2nd mosfet (at least) is defective and leaking.

[rediii]

Re: Lenovo Thinkpad E15 board NM-D011 power

Hi, Lenovo Thinkpad E15, board NM-D011 problem with power in USB-C.

The problem is the low voltages on the gates of the transistors as shown in the pic1.
The slightly conductive transistors got very hot until they broke the connection.
Transistors need 4.5V at the gates to conduct, so the voltage should be around 25V.
It seems that the fault is in the transistor control system, in the photo TP565994, I found a pdf TPS65994 which is probably the same system in a different housing.
If I understood the pdf correctly, the system is programmable, so buying a new one without software will not be successful. Please correct me if I misunderstood it.
TP565994 works with UB9 CAT24C256 memory, so it's possible that there is some configuration in it. I wonder if reprogramming this memory wouldn't solve the problem. I'd like to try a file for it.
Regards.

https://cdn.badcaps-static.com/pdfs/...ca08711b51.pdf

i doubt that they are programmed, these usb c controllers tend to fail, especially when using fake chargers

[warsztat]

Re: Lenovo Thinkpad E15 board NM-D011 power

Thanks for answers.

These are N-channel mosfets so yes, the gate should be HIGHER than the voltage being passed between source/drain pins to enable.

Respectively, the voltage should not be passing if the gate voltage is so low at 4v5.

Remove all power. Remove fuse F6101 for now.

Power up again. What is the voltage to ground of the 2nd dcin mosfet at F6101 pcb pads? It should be ~0 volts.

If not, remove all power, meter in resistance mode.

Measure the resistance across:

Source (1-2-3) & drain (5-6-7-8)
Source (1-2-3) & gate (4)
Gate (4) & Drain (5-6-7-8)

Post each measurement. Do these checks for each of the DCin mosfets. Suspecting that the 2nd mosfet (at least) is defective and leaking.

I replaced both transistors with AON7400 which seem to be good replacements but the effect is the same, the voltages are as in Fig.1. No VINT20 voltage without transistors.
Using a tabletop power supply set to 25V, I applied this voltage through 68 kohm resistors to the gates of the transistors, but the TPS pulled it down to 20.6V as if it were a zener diode.

[Sephir0th]

Re: Lenovo Thinkpad E15 board NM-D011 power

It can't work like this.

You want a dodgy solution? Then just jumper the mosfets. Of course you would lose some important protection for the board, so nobody serious would share a advise like that.

Otherwise we need more informations. What voltages do you get at VCC3_LDO_PD, ACDCIN1, ACDCIN2 and TBTA_VBUS20? Resistance to GND of VINT20_IN?

[warsztat]

Re: Lenovo Thinkpad E15 board NM-D011 power

1. VCC3_LDO_PD ~ 84Kohm for GND, voltage = 3,44V.

2. VINT20_IN over range, in the diode test the same no resistance to GND, voltage = 18,3V.

3. TBTA_VBUS20 ~ 135Kohm, voltage with power supply = 20,3V.
Power Supply Lenovo 65W USB-C after plug voltage 5V changes to 20,3V so control works.
I find only a similar boardview, haven't found ADCIN1 and ADCIN2 yet.


I bridge only QB6 mosfet, then the laptop can be turned on and the battery charging works but the qb5 heats up because there is a voltage drop on its diode.
The voltage at the QB5 gate is 0.3V higher than the voltage from the power supply, so something is going on there.

I hope I am understood, sorry for the mistakes.


ADCIN1 = 0,4V
ADCIN2 = 3,5V

I think the are correct.

[warsztat]

Re: Lenovo Thinkpad E15 board NM-D011 power

I noticed that the UB7 heats up after a while, I missed it before. It's too hot.
Thank you all very much, best regards.

[rediii]

Re: Lenovo Thinkpad E15 board NM-D011 power

I noticed that the UB7 heats up after a while, I missed it before. It's too hot.
Thank you all very much, best regards.

good luck!

[kris-ark]

Re: Lenovo Thinkpad E15 board NM-D011 power

Cześć, czy poradziłeś sobie z tym problemem zasilania w NM-D011 bo mam taki sam przypadek i już kopie temat dłuższy czas i nic.
Myślisz, że TP565994AD jest programowalnym układem?

Hello, did you manage to solve this problem in NM-D011 because I have such a case and I've been digging through the topic for some time and nothing.
Do you think TP565994AD is a software chip?

[mferna14]

Re: Lenovo Thinkpad E15 board NM-D011 power

Cześć, czy poradziłeś sobie z tym problemem zasilania w NM-D011 bo mam taki sam przypadek i już kopie temat dłuższy czas i nic.
Myślisz, że TP565994AD jest programowalnym układem?

Hello, did you manage to solve this problem in NM-D011 because I have such a case and I've been digging through the topic for some time and nothing.
Do you think TP565994AD is a software chip?

At the back of this board NM-D011., there two MOFETS AON7400 x 2... Kindly remove both the MOSFETs, you will notice the dry solder on the pads. Now either replace them with new one & use larger AMPs MOSFETS or clean these FETs with alcohol & add new solder. The original are 30A but I used AON7702 which is 37A & after this replacement use a rubber coolant pad covering the IC & both the MOSFETs, the problem get resolved. Try it & you might figure out yourself.

[mustangank]

Re: Lenovo Thinkpad E15 board NM-D011 power



At the back of this board NM-D011., there two MOFETS AON7400 x 2... Kindly remove both the MOSFETs, you will notice the dry solder on the pads. Now either replace them with new one & use larger AMPs MOSFETS or clean these FETs with alcohol & add new solder. The original are 30A but I used AON7702 which is 37A & after this replacement use a rubber coolant pad covering the IC & both the MOSFETs, the problem get resolved. Try it & you might figure out yourself.

Thank you very much