820-3209 no vcore

[G.Beard]

Board history: Liquid, attempted repair.

All the usual rails are fine.

Been all over testing this board am lost at this point.


L7550 to ground 1.5 ohm
L7510 to ground 2 ohm (get the same on donor boards but nothing working to reference)

PPVCORE_S0_CPU = 0v
PPVCORE_S0_AXG = 0v
CPUIMVP_TON = 0.7v
CPUIMVP_PGOOD = 0.5v


PPVCCAS_S0_CPU = 0.9v
PP1V05_S0 = 1.5v
PP1v8_s0 = 1v8



What do I need to be looking for please?

 

[Gurmon]

Whats the value of ALL_SYS_PWRGD ?

 

[G.Beard]

Whats the value of ALL_SYS_PWRGD ?

ALL_SYS_PWRGD 0.07v

 

[dukefawks]

ALL_SYS should of course be there. There is a rail missing.....

 

[G.Beard]

ALL_SYS should of course be there. There is a rail missing.....

Sure, I did miss one. R2805 was missing from the board (Not a no stuff right?) Fan spins now.
Now there is no chime, no mouse LED, no PRAM reset.... Now to find the issue there.

 

[G.Beard]

ALL_SYS_PWRGD now 3v3. PP1V5 is now present.

Still no vcore

 

[dukefawks]

Yeah and how did that resistor end up missing? Inspect for more damage, there is more you missed.

 

[G.Beard]

Yeah and how did that resistor end up missing? Inspect for more damage, there is more you missed.

eBay board. And yes clearly.

This board is really doing my nut.

Could this be SPIROM? Missing PM signal? PCH? Fucked up trace / Resistor / cap?

Here are few measurements but what do I need to be looking for please..... Any clues?

ALL_SYS =3v3
CPUIMVP_TON = 0.35v
CPUIMVP_VR_ON =3.3v
CPUIMVP_PGOOD = 0.06v

CPUIMVP_BOOT1G is 4.8v
CPIIMVP_BOOT1_RC is 4.8v

 

[dukefawks]

Ebay garbage. Any missing/damaged resistor can cause this. Why do you pick up this garbage?

 

[G.Beard]

Ebay garbage. Any missing/damaged resistor can cause this. Why do you pick up this garbage?

I'll send it back for a refund.

 

[dukefawks]

Uhm I assume you bought this as non-working?