(347) 552-2258 [email protected]

820-3437 no pp5v_s0

P

PPVCC_S0_CPU

Member
Previous repair attempt board,
pp5v_s0 is missing and so is pp5v_s4rs3 but as soon i remove u8080, pp5v_s4rs3 comes back, resistance to ground on 5v_s0 line is around 90k and diode mode reading is .440.
this the second board with same problem And I don't know what else to do.
when i pht u8080, diode mode measurement on 5vs4rs3 drops to 0.71 and it goes normal when u8080 is removed.
i have measured voltage drop across ppvcc_s0_cpu_ph2 and its close to 0.011.
any ideas??
 
2informaticos

2informaticos

Administrator
Staff member
"resistance to ground on 5v_s0 line is around 90k and diode mode reading is .440.
-----------------------------------
when i pht u8080, diode mode measurement on 5vs4rs3 drops to 0.71"
0.71=0.710 > 0.440
I'm really get confused.
Please provide accurate information.

Does it stay on in SMC bypass mode?
 
P

PPVCC_S0_CPU

Member
I have changed few components, and now pp5v_s4rs3 and pp5v_s0 are pulsing, and fan is repeatedly coming on and off
What should be diode measurement on ppvcc_s0_cpu_ph1 and ph2?? I am getting around 0.07
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Just found .027 in a scrap board here,
But that value depends by CPU type...
i7 shows less than i5, higer value for i3; DMM used also counts.
This board should make 3 start intents before stays on.
Check resistors/traces around SPI chip U6100.
Try new BIOS too.
Be sure U1950 has pulses (at least) at pins 7 & 3 too.
BTW VCORE pulses?
 
P

PPVCC_S0_CPU

Member
U8080, earlier old u8080 was causing short in pp5v_s4rs3 line, i changed it and all rails from pp5v_s4rs3 to vcore started pulsing if i remove it i get stable pp5v_s4rs3, but there is no short on pp5v_s0 line
 
You must log in or register to reply here.
Top