820-3787 PM_SLP_S3_L Power Cycling 15in retina

supamodz

Member
Hey guys i'm kind of stumped on this PM_SLP_S3_L is power cycling any ideas on where i should look next ?
 

2informaticos

Administrator
Staff member
Only PM_SLP_S3_L?
PM_SLP_SUS_L, PM_SLP_S4_L stable???
What about 3V3_S5, 5V_S5, 3V3_SUS?
ALL_SYS_PWRGD pulsing too?
 

2informaticos

Administrator
Staff member
Please, do NOT quote an entire message from 5cm above.

I asked for 25MHz oscillation, not pulsing at U1900?

"Also check for pulse at all big coils."
 

supamodz

Member
the reason i said pin 9 of u1900 is pulsing because i cant get a steady wave form its at about 78 to 133mhz constantly pulsing on and off there is a different reading everytime
 

2informaticos

Administrator
Staff member
Pin9/U1900 is normally 0.7V, or 1.7V DC (I do not exactly remember) when 25MHz oscillation is present.
However, only o-scope, or frequency meter can confirm 100% correct oscillation...
 
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