ASUS X556UJ_MB rev 2.0 touchpad

[caprigtx]

My touchpad is not working , cant find the solution . i tryed 1 other toupad , but same problem. is it directly conected to cpu , or is it driven by other stuff?

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Hi. See attached. These are boardview screen grabs - no schematics exist from my search in my database.

1) The trackpad operates using the I2C signals which are 2 line interfaces. One is for data (SDA) and the other for the clock (CLK). Each pair of signals must reach the PCH to communicate.

2) Do you have a multimeter for testing ? Configure for DC volts scale of 5 volts or higher is ok.

Check the voltage with red meter lead to pin # 1 = should be ~3v3 and black meter lead to ground - a metal shield on the logic board is ok.

Start with this confirmation first.

Next, move the red meter lead to pin # 3 & ground. Voltage reading ?

Then pin # 4 & ground.

Then pins 6 and 7 in the same way.

We want to know the voltage readings for each of these test points when the logic board is powered up. Often such interfaces will get killed from a liquid short or ESD damage and prevent communication to the host (I2C Bus Master controller).

Post the measurements along with the pins you have tested. Recommend that you do this with the original trackpad unless you are 100% sure the replacement is a valid replacement.

[xpuko]

Re: ASUS X556UJ_MB rev 2.0 touchpad

My touchpad is not working , cant find the solution . i tryed 1 other toupad , but same problem. is it directly conected to cpu , or is it driven by other stuff?

Try to restore the default bios settings

[caprigtx]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Try to restore the default bios settings

I already did that , but no result.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Hi. See attached. These are boardview screen grabs - no schematics exist from my search in my database.

1) The trackpad operates using the I2C signals which are 2 line interfaces. One is for data (SDA) and the other for the clock (CLK). Each pair of signals must reach the PCH to communicate.

2) Do you have a multimeter for testing ? Configure for DC volts scale of 5 volts or higher is ok.

Check the voltage with red meter lead to pin # 1 = should be ~3v3 and black meter lead to ground - a metal shield on the logic board is ok.

Start with this confirmation first.

Next, move the red meter lead to pin # 3 & ground. Voltage reading ?

Then pin # 4 & ground.

Then pins 6 and 7 in the same way.

We want to know the voltage readings for each of these test points when the logic board is powered up. Often such interfaces will get killed from a liquid short or ESD damage and prevent communication to the host (I2C Bus Master controller).

Post the measurements along with the pins you have tested. Recommend that you do this with the original trackpad unless you are 100% sure the replacement is a valid replacement.

Thanks also for this. I just picked up the same laptop and it has three issues; battery not working/charging, trackpad not working and sound chip not detected.

I have another ASUS touchpad with 7 pins and it also didn't work so suspecting mainboard fault. I'll post back after testing as above.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Check the voltage with red meter lead to pin # 1 = should be ~3v3 and black meter lead to ground - a metal shield on the logic board is ok.

Next, move the red meter lead to pin # 3 & ground. Voltage reading ?

Then pin # 4 & ground.

Then pins 6 and 7 in the same way.

Here are my results. Do we think my trackpad is at fault or mainboard? Thanks!

1 3.3
3 1.4
4 1.4
6 3.3
7 3.3

EDIT: On the trackpad, pin 4 has no voltage!

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Remove the track pad cable and measure the same pins again. Post the voltage readings for each pin.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

remove the track pad cable and measure the same pins again. Post the voltage readings for each pin.

1 3.4
2 0
3 0
4 0
5 0
6 3.4
7 3.4
8 3.4

Oh and I didn't realise, slight difference; mine is a X555UJ rev2

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Add the track pad and post the voltage readings again.

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

See attached.

Remove all power / no battery -> with the trackpad cable attached & meter in resistance mode -> check the resistance to ground for each of the trackpad I2C pins (SCL & DATA).

One meter probe on the SCL; other to ground -> what is the reading ?

Repeat for the DAT_C line in the same manner.

Next, flux and remove D3101 ESD diode array. Measure the voltage again on the above 2 points of interest.

Post the readings.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

add the track pad and post the voltage readings again.

1 3.3
2 2.0
3 1.4
4 1.5
5 0
6 3.3
7 3.3
8 3.3

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

See attached.

Remove all power / no battery -> with the trackpad cable attached & meter in resistance mode -> check the resistance to ground for each of the trackpad I2C pins (SCL & DATA).

One meter probe on the SCL; other to ground -> what is the reading ?

Repeat for the DAT_C line in the same manner.

Next, flux and remove D3101 ESD diode array. Measure the voltage again on the above 2 points of interest.

Post the readings.

My pins appear different on x555UJ (attached)

1 9.2k
2
3
4
5 3ohm
6 14k
7 14k
8 18k

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

comparing with boardview, I don't have d or q 3101.

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

When you select pin #3 or #4 on the connector, which other parts are mating to these contacts?

Perhaps the esd diode is on the other side of the board?

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

When you select pin #3 or #4 on the connector, which other parts are mating to these contacts?

Perhaps the esd diode is on the other side of the board?

Well i'm more confused now. Those components are missing too and no signs of flux. It was sold to me as having a bad battery and no sound.

They then trace to other components also not present, pictures 3/4

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

This is nearly the exact board version I have:
https://devicedb.xyz/dev/file/3886-a...boardview-asc/

I think the boardview files here at badcaps for X555UJ are not quite for this one.
Mine is 60nb0ag0-mb1112

I traced continuity from pin5 to this chip:

[mon2]

Re: ASUS X556UJ_MB rev 2.0 touchpad

As a test, flux and remove this part. Test again without this part.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Will do! So far though, would you say there is anything obvious to suggest a mainboard fault? There isn't much on the touchpad and I have continuity to it via the ribbon cable but it's relatively cheap to replace. (albeit a 2 month shipping time)

[SMDFlea]

Re: ASUS X556UJ_MB rev 2.0 touchpad

1 3.3
2 2.0
3 1.4
4 1.5
5 0
6 3.3
7 3.3
8 3.3

Pin 5 is actually pin 4 GND

60NB0AG0-MB1111 boardview https://www.badcaps.net/forum/showpo...76&postcount=4
.

[steve.rand]

Re: ASUS X556UJ_MB rev 2.0 touchpad

Pin 5 is actually pin 4 GND

60NB0AG0-MB1111 boardview https://www.badcaps.net/forum/showpo...76&postcount=4
.

Yeah I think that's the same as my link above. I will triple check that pin.