HP 8470p, Battery isnt Detected.

[echo26]

Hi, Ive read the pinned Charging Circuit memo. It was advised to check the Charging SDA and SCL. However I believe these must be checked using an ocilloscope. I only have an analog multimeter along with me. I needed help as I have changed the battery already but still isnt detected. Drivers were uninstalled and reinstalled however still no sign on sucess. The amber lights up when plugged in, laptop hangs up with keyboard and mouse unresponsive except power button, sometimes doesnt boot on battery. Now the new battery I believe is already drained as not being charged. When Left charging on adapter, teh amber light non-stops on blinking. Laptop is working fine without the battery but I badly needed it to be having a working battery for ease.

As I am asking for help, I would like to know what Voltages I needed to post here in order for you to be able to help. I would have to disassemble the laptop and will be deemed unusable so I ahve to use my phone. I have a schematic so it wont be a problem identifying pins and pads.

Tried new Charger btw, still have the same issue baout the battery not being detected. I tried finally to test the battery with th T-pin(pin 6) pulled down to ground (pin 8) with a multimeter and no Voltage isnt showing anymore with pin 1 to pin 8. probably the battery already shut off because it was drained. I am trying to aquire a new battery again. If I can get the desired voltages, maybe that will send me to a resolution for the problem. Thanks.


I have attached the boardview and the schematics for anyone to look to make it easier.

[mon2]

Re: HP 8470p, Battery isnt Detected.

Analog meter is fine. Need to check if the I2C (SMBUS) lines; SCL & SDA are stuck or not.

Meter in DC volts scale.

Check the voltage on SCL (red meter probe); black meter probe to ground. What is the reading ? It should be ~3v3 if ok.

Repeat for the SDA line.

Post your readings.

PS: You are working late

[echo26]

Re: HP 8470p, Battery isnt Detected.

Analog meter is fine. Need to check if the I2C (SMBUS) lines; SCL & SDA are stuck or not.

Meter in DC volts scale.

Check the voltage on SCL (red meter probe); black meter probe to ground. What is the reading ? It should be ~3v3 if ok.

Repeat for the SDA line.

Post your readings.

PS: You are working late

Hey Thanks for the quick reply, will do it right now.

[mon2]

Re: HP 8470p, Battery isnt Detected.

I see 2 different I2C bus connections for the battery - not sure why but best to check both of them for stuck logic levels.

Which connector is using your battery pack ?

[echo26]

Re: HP 8470p, Battery isnt Detected.

I see 2 different I2C bus connections for the battery - not sure why but best to check both of them for stuck logic levels.

Which connector is using your battery pack ?

Cn6050 to be exact.

[mon2]

Re: HP 8470p, Battery isnt Detected.

Ok - confirm the voltage @ SDA_MAIN & SCL_MAIN.

[echo26]

Re: HP 8470p, Battery isnt Detected.

Analog meter is fine. Need to check if the I2C (SMBUS) lines; SCL & SDA are stuck or not.

Meter in DC volts scale.

Check the voltage on SCL (red meter probe); black meter probe to ground. What is the reading ? It should be ~3v3 if ok.

Repeat for the SDA line.

Post your readings.

PS: You are working late

SDA 3.3v
SCL 1V

[echo26]

Re: HP 8470p, Battery isnt Detected.

Ok - confirm the voltage @ SDA_MAIN & SCL_MAIN.

Sda 3.3
SCL 1v

No battery, just adapter.

Resistance in respect to ground showing 4.5ohms to 4.7ohms

[mon2]

Re: HP 8470p, Battery isnt Detected.

Your SCL line is stuck. It should be 3v3.

Remove all power. BRB.

[echo26]

Re: HP 8470p, Battery isnt Detected.

Your SCL line is stuck. It should be 3v3.

Remove all power. BRB.

Ok, no power is applied. Board is at rest.

[mon2]

Re: HP 8470p, Battery isnt Detected.

Check the resistance to ground of the same lines. No power while testing the resistance.

[echo26]

Re: HP 8470p, Battery isnt Detected.

Check the resistance to ground of the same lines. No power while testing the resistance.

7.8-8ohms. both are measured from the #3 pin of the fets in respect to ground.

[mon2]

Re: HP 8470p, Battery isnt Detected.

The readings do not sound correct but ignore for now. They sound very low in resistance.

See attached. Remove the ESD diode @ D7500 off the board.

Then check the voltage again on the same SDA & SCL lines.

Post the readings.

[echo26]

Re: HP 8470p, Battery isnt Detected.

The readings do not sound correct but ignore for now. They sound very low in resistance.

See attached. Remove the ESD diode @ D7500 off the board.

Then check the voltage again on the same SDA & SCL lines.

Post the readings.

Sorry, got the values mixed. It was the 7501 that is stuck on 1.1v. should I remove that instead.

[echo26]

Re: HP 8470p, Battery isnt Detected.

Removed 7501, still stuck to 1.1V, SCL is 3.3 just as earlier.

[mon2]

Re: HP 8470p, Battery isnt Detected.

Well noted. Check the resistance of R6050. Is it 2k2 ?

Remove the diode @ D7504 (right side of the schematic). My bad, this is the ESD diode for the SDA line.

Check the voltage again after this removal of the part.

You can solder back the D7501 part since it is not the guilty party.

[echo26]

Re: HP 8470p, Battery isnt Detected.

Well noted. Check the resistance of R6050. Is it 2k2 ?

Remove the diode @ D7504 (right side of the schematic). My bad, this is the ESD diode for the SDA line.

Check the voltage again after this removal of the part.

You can solder back the D7501 part since it is not the guilty party.

I was actually looking into the Resistor haha, I can't still find it. It's hard without having a board view. Forgive me if I reply slow because I only use my eyes to locate the parts 😂😂

[mon2]

Re: HP 8470p, Battery isnt Detected.

If it helps, post pics. Should be nearby the battery connector. Likely black in body color and it may or may not have a white band.The part is not polarized so may not have a band on it.

[echo26]

Re: HP 8470p, Battery isnt Detected.

If it helps, post pics. Should be nearby the battery connector. Likely black in body color and it may or may not have a white band.The part is not polarized so may not have a band on it.

Yep, can't still find that Resistor, I only found the 100ohms Resistor on top the pin 3 of the diodes.

[mon2]

Re: HP 8470p, Battery isnt Detected.

Could it be on the other side of the logic board ? Post those pics. About to take my late lunch.