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[SOLVED]820-3209-a No Power

W

wirelessplanet

Member
I get orange/green light. Board does not power on or fan spin.

had some small spots of corrosion - replaced r1517 and c2450

PPBUS_G3H 8.4
PPBUS_S5_HS_OTHER_ISNS 8.4
PPBUS_S5_HS_COPMUTING_ISNS 8.4
PPDCIN_G3H 16.07
PP3V42_G3H 3.42
PPVRTC_G3H 3.42
PP5V_S0 - 0
PP3V3_S5 0
PPV3V_S0 0
PP1V8_S0 0
PP1V5_S0 0
 
smiba

smiba

New member
You're probably missing SMC_PM_G2_EN

Voltage of SMC_PM_G2_EN and SMC_BC_ACOK?

I can't find R1517 on my schematic by the way
 
smiba

smiba

New member
No missing that test point would at best cause issues in S0, but you're not even fully getting into S5

Voltage of PP5V_S5, P5VP3V3_VREG3 & P5VP3V3_VREF2?
Voltage of P3V3S5_EN_R?
Voltage of PPVIN_S5_P5VP3V3 probed at C7200?
Voltage of Pin 12 of U7201? (Probed at the pin or otherwise as close as possible)

I'm suspecting U7201 trouble
 
W

wirelessplanet

Member
PP5V_S5 - 5.040
P5VP3V3_VREG3 - 3.304
P5VP3V3_VREF2 - 2.003
P3V3S5_EN_R - 3.423
C7200 - 8.4 (my does schematic not say PPVIN_S5_P5VP3V3. it says PPBUS_S5_HS_OTHER_ISNS)
Pin 12 is P5V3V3_REG_EN - 3.422
 
smiba

smiba

New member
R7206, R7216, R7238, R7246 and R7260/61 within specifications?

Resistance to ground on PP3V3_S5 in Ohms?
 
W

wirelessplanet

Member
r7206 - 247k
r7216 - 1.248k ( this is off will change)
R7238 - 7.5
R7246 - 1.250
R7260 - 6.98 (this is off will change)
R7261 - 7.00 (this is off will change)

Resistance to ground on PP3V3_S5 - .3-.4

is it weird that so many resistors are bad? just wondering before i replace them.
 
smiba

smiba

New member
wirelessplanet said:
is it weird that so many resistors are bad? just wondering before i replace them.
Click to expand...

The resistors are all good, in almost all cases a resistor fails high resistance. The lower resistance measurements are simply because the electricity found a different way to flow


The resistance to ground on PP3V3_S5 is bad though, that shoudn't be so low.

Inject 1V into it and start with something like 2 Amps and increase after a while if nothing noticeable heats up. Only increase voltage if you're running into an amperage limit
Its probably a capacitor or IC shorted somewhere, see what heats up. Use alcohol when you have found a spot that is somewhat hot, unless you want to make the same mistake as me by burning the tip of your finger on a shitty 0402 capacitor thats burning hot ;)
 
W

wirelessplanet

Member
So i shouldn't replace them?

r7216 should be 6.65k and i'm only getting 1.248
r7260 should be 23.2 and i'm only getting 7
r7261should be 10 and i'm only getting 7
 
Gurmon

Gurmon

Member
No, dont replace the resistors. Remove L7260, see which pad the short is on, and the inject power as Smiba has explained.
 
W

wirelessplanet

Member
so the power supply is maxing out at 1.5amps. c9487 is the only thing that gets slightly warm, not boiling hot. its showed a short on multimeter so i removed and short was still there. any other ideas?
 
smiba

smiba

New member
To battle the supply maxing out: increase the voltage, the maximum allowed in this case is 3.3V.
 
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