820-00165

Justrepairs Ltd

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Cheers for that

I have 820-00165 no liquid damaged it’s clean board missing pm_slp_S4 on power supply I’m getting 0.031 Am I thinking it’s
dead cpu. S4 en is missing
 

2informaticos

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Is a long way to diagnose dead CPU; at least with the info posted...

PM_SLP_S4_L doesn't even pulse?
Did you check basic signals from Power On Sequence?
 

Justrepairs Ltd

New member
hi checked all these
ppbus_g3h 8.60v ok
ppbus_s5 8.60v ok
ppbus_hso 8.60v ok
dcin isol 8.60v ok
dcin g3h 8.60v ok
pp3v42_g 3.42v ok
ppvrtc_g3 3.00v ok
pp5v_s5 5.00v ok
pp5vs4 5.00v missing
s4 en missing
Pm_slp_s4 missing
pm_dsw_pwrgd ok
 

2informaticos

Administrator
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"pm_slp_s4 plusing yes"
PP5V_S4 should pulse too.
Check all big coils for pulse.
AL_SYS_PWRGD pulses too?

BTW, always better to check for pulses on power rails with o-scope...
 

Justrepairs Ltd

New member
PP5V_S4 PULSING YES
AL_SYS_PWRGD PULSING YES
S4 EN PULSING YES

ALL COILS PLUSING APART FROM L7560 AND L7130
ALL CHECKed WITH O-SCOPE

I HAD SCOPE AT 200mV
 

2informaticos

Administrator
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"ALL COILS PLUSING"
So L7310/20 pulse too?

"APART FROM L7560 AND L7130"
Is normal, these have steady voltage.
I was reffering to the rest of coils.

The o-scope should catch peak level of a power rail, or signal.

Check if pins 7 & 3 of U1950 pulse too.
 

2informaticos

Administrator
Staff member
"So L7310/20 pulse too?"

Check SPI termination resistors and traces for U6100.
Don't forget to look at U6101 too.
 

2informaticos

Administrator
Staff member
Don't look, measure...

Check for short, or low resistance on the power rails from page 58.
Also check PP1V5_S0.
 

2informaticos

Administrator
Staff member
L7820 pulsing?
Any short there?
If not, heck voltages for U7820.
Same 1V8_S3 should go to U7870.

However check pins 1, 3, 6 of U7870 for pulse, not for steady voltage...
 

Justrepairs Ltd

New member
u7870
pin 1 0v plusing
pin 2 un
pin 3 0v plusing
pin 4 3.2v
pin 5 gnd
pin 6 0v plusing

l7820 0v plusing diode mode 0.665 both side

u7820
pin 1 3.2v
pin 2 0v plusing
pin 3 0v plusing
pin 4 3.2v
pin 5 gnd
pin 6 0v plusing
pin 7 gnd
pin 8 0v plusing
 
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