[SOLVED]820-00165-a, shut down by itself after 20 sec

[Don Anton]

Hi, This is liquied damaged and some one has cleaned before. There is no visible corrosion or damaged as I cheked with microscope. board is pretty clean. cheked only with dc in board and fan same out come.
All the power rails present accurately then after 20 sec missing pm_slp_s4. ppvcc_s0 12.1 ohms resistance to ground. smc reset works. doesnt respond to pram reset when it boots. takes 12 secnds to get the chime . u7100/u6100 pretty clean and voltages are accurate. greatly appriciate your help.

 

[dukefawks]

Disconnected keyboard? Check SMC_ONOFF, it may be getting pulled down.

 

[Don Anton]

Hi Duke, Thanks for the quick reply.nothing connected other than DC in board. SMC_ONOFF stable 3.4v even after fan stoped.

 

[dukefawks]

Does the board boot, is there an image?

 

[Don Anton]

Hi Duke, Yes it is boots after 12 sec fan spinging I get the chime and apple logo. then auto turn off . now nothing connected other tha dc jack as soon connect the magsafe fan spins then after 20 sec auto turn off

 

[dukefawks]

Could be anything really, possibly crap under the SMC? Can you turn it back on by shorting R5115/6?

 

[Don Anton]

yes I can turn it on back shorting R5115 or 16

 

[Don Anton]

Smc you recon I should replace the smc and check?

 

[dukefawks]

First try a reflow of the SMC. Inspect board closely for other corrosion too.

 

[Don Anton]

Hi Duke. SMC Replaced. and thanks to you it is working again smoothly . Thanks lot for your guidance Duke.