Lenovo SL400 Dead. Need Help

[Jesse James]

I have a Lenovo Rocky 40-50 board that battery light comes on and charges but thats it. I know its old but in mint shape. I have traced power sequence and found SIO is seeing the following
power button
SUS_PWRGD
RSMRST
My 3.3v and 5v are present but what i did notice was no
SYSTEM_PWRGD at SIO
no PM_PWRBTN out of SIO
no +3vs on pin 11 going to SIO
I get confused if 3vs is always present or not.
I have attached schematics i am working with.
Any help would be appreciated
Thank You

[Techtiger]

Re: Lenovo SL400 Dead. Need Help

test TPS51120 pin 19 & 21 , you need +3VA for SIO BIOS ect ,+3VS comes after PWRBTN ,do you have 3.3V on RSMRST ?

[khaahk]

Re: Lenovo SL400 Dead. Need Help

PWRSW# comes to sio?
LID_SW# is high?
How much current is drawn from adapter?
Does sio get warm? (if current drawn is higher than 30mA)

[Techtiger]

Re: Lenovo SL400 Dead. Need Help

Test U8101 pin 5 +12VSUS , SIO pin 14 EC RST

[Jesse James]

Re: Lenovo SL400 Dead. Need Help

Thanks for the quick info. Here is what i have

Bios pin 8=3.3v
EC RST= 2.82V
U8101 pin 5=12v
Lid_SW# =3.3V
RSMRST=3.3v
PWRSW# =3.3V and goes to 0v on sio when pressed
TPS51120 pin19=3.3v
pin21=5v

Current draw with psu is 10mA
It goes to 15-20mA when power button pressed
Nothing on the board warms up

Does this look like a dead sio

[Techtiger]

Re: Lenovo SL400 Dead. Need Help

Does it have activity on BIOS CS# pin?
Any activity on pin 121 & 25 SIO PM SUSB PM_SUSC
Check pin 3 & 7 , try and flach Bios save the OLD Dump first

[Jesse James]

Re: Lenovo SL400 Dead. Need Help

No activity on CS# 3.3v
sio pin 121 & 25 no activity
No activity on any pins but all i have is volt meter
I flashed the bios with one found online and still no change (saved old dump)

[khaahk]

Re: Lenovo SL400 Dead. Need Help

what do you mean by:

no PM_PWRBTN out of SIO

[Jesse James]

Re: Lenovo SL400 Dead. Need Help

I assume PM_PWRBTN is the output from sio to ICH but not sure
It has 3.3v but no change when pressing power button
My input from power button to sio goes to 0 when pressed

[khaahk]

Re: Lenovo SL400 Dead. Need Help

It should go up to 3V after pressing powerbtn and then low for a moment but you can not see it with multimeter. ICH should respond with susb and susc going high, if i am correct. Does it happen?

[on/off]

Re: Lenovo SL400 Dead. Need Help

RTCRST# and SRTCRST# signal?

[Jesse James]

Re: Lenovo SL400 Dead. Need Help

Sorry wrote that wrong and too late to edit
PM_PWRBTN 0v and does not change
susb and susc 0.23v and does not change
I have not been able to trace RTCRST# and SRTCRST# as this board does not have any reference other than JP and H.

[khaahk]

Re: Lenovo SL400 Dead. Need Help

Does this look like a dead sio

Looks like it.

[Jesse James]

Re: Lenovo SL400 Dead. Need Help

I found a boardview that is similar and have been able to test further. It looks to me like a faulty TPS51120 chip. Does anyone know if there is a chip equivalent to this as I have some used boards to use.