820-3437 power on problems

[tlough75]

Hello, got yet another 820-3437 with problems. This one has PP3V42 at 3.41V, PPBUS is 8.59V. I am missing PM_SLP_S4_L. When I power it on, the current spikes to .452A then drops to 26mA. Seems to me like it is trying to power on then shutting down. I checked some power rails but these boards I get with this issue and no apparent corrosion anywhere are baffling. I have 2 of them.

 

[2informaticos]

If board tries to start PM_SLP_S4_L pulses at least; check if PM_SLP_S3_L too.
This board should make 2 attempts before starting.
Check if all voltages pulse, including VCORE.
Any history available?
Check for corrosion, especially at U1950.