Lenovo G505 la-9912p not charging

[Bisketti]

Hi I have an issue with this laptop charging, the battery is ok as I charged it with similar model. The charging ic is BQ24727.
pin 1-20v
pin 2-20v
pin 5- 0v
pin 6-2.8v
pin 7-0v
pin 8-3.3v
pin 9-3.3v
pin 10-0v
pin 11-.49v
pin 12-11.8v
pin 13-11.8v
pin 14-0v
pin 15-.1v
pin 16-6v
pin 17-11.6v
pin 19-11.8v
pin 20-18.3v

Any ideas welcomed.

[piernov]

Re: Lenovo G505 la-9912p not charging

You've got 11.8V on the battery line, so it is charging or is already fully charged as far as I understand it. Check what's the battery nominal voltage is on its sticker.

[Bisketti]

Re: Lenovo G505 la-9912p not charging

You've got 11.8V on the battery line, so it is charging or is already fully charged as far as I understand it. Check what's the battery nominal voltage is on its sticker.

It seems that way but if the battery drops to say 70% when plugged in it will say 70% charging but wont actually charge above the 70% or 80% or whatever it was currently at.

[Bisketti]

Re: Lenovo G505 la-9912p not charging

I just let it drop to 31%, I plugged into bench supply and its only drawing .442ma while on . It says 31% charging 3 ions to full charge. But thats over an hour ago.

[piernov]

Re: Lenovo G505 la-9912p not charging

And what are the voltages on the BQ24727 now (at below 40%)?

[Bisketti]

Re: Lenovo G505 la-9912p not charging

Which pins specifically ?

[Bisketti]

Re: Lenovo G505 la-9912p not charging

When its powered off it only draws .013ma.

[Bisketti]

Re: Lenovo G505 la-9912p not charging

Also looking for the boardview of this model as well. La-9912p

[Levi]

Re: Lenovo G505 la-9912p not charging

So in effect the system indicates charging but it is not actually putin in any juice into the battery therefore no increase in battery percentage. Check for short between source and drain of first 2 charger FETs.

[Bisketti]

Re: Lenovo G505 la-9912p not charging

Hi thanks for the reply, yes thats correct theres voltage but no current flowing. Both pq301 and 302 are reading ok. I changed pq309 and 310 but still no current and still batt level is 70% as I partially charged it in another laptop

[fester]

Re: Lenovo G505 la-9912p not charging

11.8V is nominal voltage for the battery,for full charge you need 4.2V pro cell(3 lion cells in series) -> you need 12.6V.

[Bisketti]

Re: Lenovo G505 la-9912p not charging

The same battery in a different Lenovo laptop charges and the voltage on pin 19 of charging Ic is 11.6v, .2v lower than the one not charging

[Bisketti]

Re: Lenovo G505 la-9912p not charging

I have changed pq301/302/pq309/310 but still exactly the same, no current flow

[fester]

Re: Lenovo G505 la-9912p not charging

current sensing resistor PR324 is ok?

[Bisketti]

Re: Lenovo G505 la-9912p not charging

yeah PR324 read .6ohm and PR301 .8ohm

[Bisketti]

Re: Lenovo G505 la-9912p not charging

Solved..it was actually faulty schottky diode Pd301. Replaced it then all working fine now.