820-4924 keyboard and trackpad only work in EFi

[ALB-Repairs]

All power rails seem to be there but it doesnt recognise the keyboard and trackpad in OSX only in EFI.

Hate these sorta issues. Board has been tested in a know good shell

 

[dukefawks]

Firstly inspect all SPI lines to the connector, or just diode mode all pins while you are at it.

 

[ALB-Repairs]

I really need to get a bench meter with diode mode dont i?

Using a vintage fluke 8840A at the moment and hate handheld multimeters.
Got out my handheld meter

1,3,5,7,9,11,13 OL

15,17,31,33,39,47,51,52,40,34,34,30,24,18,16,50,49 0 because GND


TPAD_ACTUATOR_EN_L 0.8454

SMBUS_SMC_2_S3_SDA 0.7322

SMBUS_SMC_2_S3_SCL 0.7344

PP5V_S4_TPAD_F 1.538x

PP3v3_S4 1.0045

USB_TPAD_P 0.5940

USB_TPAD_N 0.5941

IC2_IOXP_SCL OL

IOXP2_INT_L OL

TPAD_SPI_MOSI_R 1.169

TPAD_SPI_CS_CONN_L OL

TPAD_SPI_MOSI_R 1.14

TPAD_SPI_CLK_R 1.117

TPAD_SPI_IF_EN_CONN. OL

TPAD_SPI_INT_L 1.27

SMC_LID OL

SMC_PME_S4_WAKE_L. OL

TPAD_ACTUATOR_THRMTRIP_L OL

TPAD_VBUS_EN OL

GND_ACTUATOR 0.00

 

[dukefawks]

I doubt pin 1 is OL as it should connect to PPBUS. F4800 dead? Also buy a multimeter these readings look all weird. Any $5 one will do better than this.

 

[ALB-Repairs]

I can remeasure if you like duke but i should probably recharge the battery of my Agilent U1512B. Will remeasure later, i think its one of the rails that starts low and then quickly rises to OL.

Im confused, are you suggesting my top end Agilent multimeter is not up to standards?

Other than some very negligible difference i had it side to side with a working board when i took the measurements and didnt see anything wrong with the value.
I also inspected the SPI lines, all traces and resistors are good.

 

[Gurmon]

I had this shit yesterday. I just remapped the trackpad/keyboard. . All was ok again.

 

[ALB-Repairs]

Did it show as a device? i get the bluetooth keyboard assistant pop up. Ive also tried it on a different SSD.

Ive done all the other stuff like PRAM reset and reflash the bios

 

[Gurmon]

There was no activity for keyboard or trackpad in OSX. I didn't bother testing too much as figured it was trackpad related,since logic worked perfect in known good 2015 top case.

I might have just got lucky.

Do you have a pre-programmed trackpad in stock ?

 

[ALB-Repairs]

the trackpad is confirmed working (i always seem to have more than 1 4924 system in stock that i get to use as a testing shell.

 

[dukefawks]

Looking at your measurements "SMC_LID OL" just makes no sense. I cannot trust any of those measurements.

 

[ALB-Repairs]

No Title

Had a brainfart.
Ignore old measurements. New measurements here, compared to two good boards. Cant see anything suspect, but the second good board seems a bit our of whack. (second good board has some corrosion on its trackpad connector though)
Measurements uploaded as a picture to keep the formatting

 

[dukefawks]

Can you measure 3v3_s4, PPVIN_S4 and 5V_S4 with trackpad connected? If they are ok then I suspect crap under the connector, or bad connector.

 

[ALB-Repairs]

All voltages you said are present and healthy with the tpad connected.
Removed the connector, no crap under it, connector replaced, no improvement, I think im done wasting time on this one.

 

[dukefawks]

Yeah, SPI goes straight into the CPU. I have a few boards here that I can't get the trackpad to work. I assume the CPU has a dead SPI line.