Y580 works on battery, but not with charger

[pingaroon]

Re: Y580 works on battery, but not with charger

Those voltages are with the board off

[mon2]

Re: Y580 works on battery, but not with charger

Hi. See attached.

1) On the working (good) board - the BATT_OUT signal is +3v3 @ location 5 of the last shared schematic. This logic '1' signal will then turn ON the mosfet (2n7002) @ PQ308.

When PQ308 is turned ON, the resistor @ PR307 (20k) will then be connected to ground.

When PQ308 is pulled down to ground, the PQ301 & PQ302 mosfets will turn ON. These mosfets turn ON when their gate voltages are negative (ie. lower) than the voltages they are passing through on the source & drain.

So for the working board, the mosfets are turning on due to the BATT_OUT signal voltage being ~ +3v3.

For the non-working board, the mosfets are OFF as BATT_OUT signal is ~ 0V which means the mosfet PQ308 will remain OFF so PR307 is floating on one side.

2) update:

The gate voltage is too high for the non-working board. Your first mosfet may be defective.

Remove all power. Meter in resistance mode (2k).

Measure and post the resistance for the following:

PQ301

source (1-2-3) & drain (5-6-7-8)
source & gate (pin 4)
gate (4) & drain (5-6-7-8)

Perform the same resistance checks on the GOOD working board.

Post both values.

Will be a good idea to take measurements from both logic boards for also PQ302.


After we can confirm the mosfet is ok or replaced, then ...

3) Based on the posted measurements, take a piece of wire and connect one side to GROUND and the other side to the PR307 resistor, pin # 2.

This bypass is effectively performing the task of PQ308 as thought it was ON.

Be sure that you are on pin # 2 of the PR307 resistor for this test.

See attached. Post your results from this testing.

4) Moving forward, the wire bypass is not the solution for this repair. We need to study how the convoluted BATT_OUT signal is generated and compare notes against the working logic board. By continuing to compare this section of the design, it should be possible to repair this board.

Post the above test results and then we can continue...

[mon2]

Re: Y580 works on battery, but not with charger

Not enough coffee for me... the mosfets are passing through the voltage on both boards.

Still confirm again the mosfet resistance readings on both boards so we can compare.

[mon2]

Re: Y580 works on battery, but not with charger

Ok. After reviewing this thread again, I think I am now in sync ('bye bye bye'?).

You have a charger fault.

Can you measure and post the voltage @ ILIM pin #10 of the charger IC PU301?

Compare the ILIM voltage against the working board. If they are indeed the same or very close in value, then it will be a good idea to measure and post the voltages for all pins of PU301 for the non-working board. Then do the same for the working board.

[pingaroon]

Re: Y580 works on battery, but not with charger

Hi, last I checked all the voltages on pu301 on all pins on both boards were the same, but I'll check again and post tomorrow. Mosfet Resistances on PQ301 and PQ302 are also similar on both boards.

The Lenovo charger is good as it's the charger from my own laptop (a Y580, surprise!) - works faultlessly. My error earlier on was to use universal adapter as I needed the Lenovo charger to actually use my laptop. That universal adapter was causing the board to immediately power off and possibly give erroneous readings posted earlier, so I took it fully out of the equation.

I thank you for your help with this thread - I realise it is taking up a lot of your time and am truly grateful.

[pingaroon]

Re: Y580 works on battery, but not with charger

Hi, here we go - voltages for PU301.

On the bad board the actual voltage of the battery is about 0.5v too low.
What should I do next?

BAD Board (brackets value is when board is on with battery - if different)

1 19.5
2 19.5
3 0
4 0.15
5 0
6 2.76
7 0
8 3.3
9 3.3
10 1.32
11 0.28 (0.37)
12 2.4 (11)
13 2.36 (11)
14 0
15 0
16 6.02
17 5.8 (10.3)
18 2.39 (11)
19 2.27 (11)
20 19.1 (19)


GOOD Board (brackets value is when board is on with battery - if different)

1 19.5
2 19.5
3 0
4 0
5 0
6 2.76
7 0
8 3.3
9 3.3
10 1.33
11 0.28 (0.4)
12 1.83 (11.5)
13 1.83 (11.5)
14 0
15 0
16 5.99
17 5.76 (11.24)
18 1.83 (11.5)
19 1.82 (11.5)
20 19.5 (19.3)

[mon2]

Re: Y580 works on battery, but not with charger

Test with the battery from the other working board. Same results ?

Respectively, if you take the non-working board -> remove the battery from this case, connect this battery to the working board -> does the battery proceed to charge properly with the good board ?

The issue could be a faulty battery since the logic board is booting with the adapter and charging does proceed, at least for a bit before halting.

Also, see attached. According to the internet, amber light on Lenovo = battery is being charged.

[pingaroon]

Re: Y580 works on battery, but not with charger

Hi, battery and charger work perfectly in my main Y580 laptop.
The battery light is amber only when it's getting low. Above a certain point it's white, like on my main laptop right now.

On the bad board, it charges (amber or white light depending on how fully charged battery is), then it blinks amber, and tries to charge again, before abandoning with the flashing amber and after several attempts it stops trying to charge the battery (no lights).

Both battery and charger are original, and the battery checks out on a battery analysis machine I have too.

Darn weird eh?

[mon2]

Re: Y580 works on battery, but not with charger

If you apply a charged battery onto the non-working board and boot into Windows, is Windows able to properly gauge the battery level ? (ie. xx %)

Respectively, you should be able to operate normally with Windows using only this pre-charged battery. After xx minutes, does the battery gauge indicate that the battery is depleting ?

Then, when you attach the adapter, does the battery charging icon appear to indicate that the battery is charging ?

[pingaroon]

Re: Y580 works on battery, but not with charger

Apologies for the delay - will be back onto this project in the New Year, so will report back findings then. Have a great Christmas!

[pingaroon]

Re: Y580 works on battery, but not with charger

Apologies for the delay - will be back onto this project in the New Year, so will report back findings then. Have a great Christmas!

Update - I've abandoned this board! When the original spec mosfets arrived, it started misbehaving in other ways. I think a previous owner has made too many changes, some incorrect, which makes it impossible to diagnose - too many moving goalposts. I thank you for all your assistance.