hgoncalves
Active member
Hello, I have an A1990 that has no power. It only pulls 5V from charger.
On PP20V_USBC_XA_VBUS it only has 5V on F3000.
Can you help me?
On PP20V_USBC_XA_VBUS it only has 5V on F3000.
Can you help me?
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A1990 820-01814-01 No power (5V on ampmetter)
- Thread starter hgoncalves
- Start date
Do you get 5V on all ports?
PPBUS_G3H is first voltage to get on T2 boards.
Check for short, or low value in diode mode.
PPBUS_G3H is first voltage to get on T2 boards.
Check for short, or low value in diode mode.
hgoncalves
Active member
Hi,
yes, i do have 5V on all ports, and PPBUS_G3H = 0V, and it's shorted (0.0029V in diode mode)
yes, i do have 5V on all ports, and PPBUS_G3H = 0V, and it's shorted (0.0029V in diode mode)
Switch to ohm mode and compare reading with the values on all big coils.
Do NOT inject voltage yet!
Do NOT inject voltage yet!
hgoncalves
Active member
Hi, Thanks.
All big coils seams to have the right values. Shell i inject voltage to see what gest's hot?
All big coils seams to have the right values. Shell i inject voltage to see what gest's hot?
Post exact ohm value to ground (not diode mode) on PPBUS_G3H first.
hgoncalves
Active member
PPBUS_G3H has 1.55 ohm to ground.
And CPU coils are not close to that ohm value???
hgoncalves
Active member
Sorry, they are.
They're 2 ohm to ground
They're 2 ohm to ground
Unfortunatelly, you didn't bother to specify which coils exactly.
Supposing the problem is on VCORE, remove U7410/20/30 one by one and check when the short disappears from PPBUS_G3H.
If still there, your problem is on iGPU coils; do the same there, if needed.
Supposing the problem is on VCORE, remove U7410/20/30 one by one and check when the short disappears from PPBUS_G3H.
If still there, your problem is on iGPU coils; do the same there, if needed.
hgoncalves
Active member
Sorry, it was not my intention to ignore your request
They are all the same:
LA430 = 1.37 ohm on PPVCORE_S0_GFX_PH3
LA640 = 1.35 ohm on PPVCORE_S0_GFX_PH2
LA650 = 1.36 ohm on PPVCORE_S0_GFX_PH1
L7231 = 2 ohm
L7221 = 2 ohm
L7211 = 2 ohm
L7330 = 24 ohm
L7420 = 5.5 ohm
L7410 = 5.5 ohm
LA300 = 174 ohm
LA350 = 28 ohm
Shel i remove U7410/20/30 ?
They are all the same:
LA430 = 1.37 ohm on PPVCORE_S0_GFX_PH3
LA640 = 1.35 ohm on PPVCORE_S0_GFX_PH2
LA650 = 1.36 ohm on PPVCORE_S0_GFX_PH1
L7231 = 2 ohm
L7221 = 2 ohm
L7211 = 2 ohm
L7330 = 24 ohm
L7420 = 5.5 ohm
L7410 = 5.5 ohm
LA300 = 174 ohm
LA350 = 28 ohm
Shel i remove U7410/20/30 ?
NO, as you have 5 ohm there.
U7210/20/30 must be checked.
My mistake in previous post; typed 74 instead of 72...
U7210/20/30 must be checked.
My mistake in previous post; typed 74 instead of 72...
hgoncalves
Active member
I don't get any voltages on U7210. Should i remove it?
You said to have short on PPBUS_G3H.
Did you apply power on the board again in this condition???
I said to remove chips one by one, and check every time resistance to ground at PPBUS_G3H.
Did you apply power on the board again in this condition???
I said to remove chips one by one, and check every time resistance to ground at PPBUS_G3H.
hgoncalves
Active member
Sorry, i miss understood.
I' going to do as you said.
I' going to do as you said.
hgoncalves
Active member
Hi, i've removed U7210/20/30 and the short persist on PPBUS_G3H (1.60 ohm to ground)
Now try removing the chips corresponding to VCORE_S0_GFX lines (one by one).
hgoncalves
Active member
Sorry, but by chips you're meaning QA340/640/650, or the UA340 / UA600?
Last edited:
"LA430 = 1.37 ohm on PPVCORE_S0_GFX_PH3
LA640 = 1.35 ohm on PPVCORE_S0_GFX_PH2
LA650 = 1.36 ohm on PPVCORE_S0_GFX_PH1"
Check associated chips...
LA640 = 1.35 ohm on PPVCORE_S0_GFX_PH2
LA650 = 1.36 ohm on PPVCORE_S0_GFX_PH1"
Check associated chips...