820-3115 running slow

pcfriends

New member
hello I have a 820-3115 board that run really slow I run ASD and shows the next bad sensors:

TA0P

TC0P

TM0P

Th1H

All are SMC IO those 4 fail

I replace : U5511 , Q5515 , Q5520 , Q5510 and I check for related resistor and caps they look good and match schematic , =PP3V3_S0_CPUTHMSNS is there , R5260 and R5261 match schematic and they have voltage.

Machine still run slow.

What I should check now?

machine chime , boot , play you tube , but slow.

thank you so much.
 

dukefawks

Administrator
Check power to U5511, R5511/12, R5510 is suspect or trace is corroded. IO is failing so it must be power to U5511 or corroded data lines to SMC. Last thing I suspect is dead SMC. You can check bad trace to SMC with multimeter on diode mode, both data lines should be about the same value.
 

aprendiz

Moderator
my bet goes to bad SMC, check pull up resistors R5260-R5261 should have about 3.3V on both sides of both resistors....
 

pcfriends

New member
R5260-R5261 they have 3.3v on both sides

Check power to U5511 : =PP3V3_S0_CPUTHMSNS is the line that power this chip? if yes that read on r5510 3.3v one side 3.2v the other side.

my reading on diode mode for SMC Lines is: on r5261 pin 2 .641 pin 1 .351 , r5260 read same
 

dukefawks

Administrator
Was the liquid damage in the SMC area? Could be crap under the SMC. Give it some flux and heat, do not reflow just 180C should be enough to clear the crap.
I checked on a good board and I measure .350 and .560 on the pull up resistors so your .641 seems a bit high. Check if there in continuity from R5260/1 to U5511
 

pcfriends

New member
Check if there in continuity from R5260/1 to U5511 I did master it beeps on booth pins 9 and 10 of u5511 , why is it that my reading is higher master? caps have nothing to do with it? I still didn't replace any cap on de U5511 area I will replace the smc when you advice is time after checking really good all the other components.
 

pcfriends

New member
man I take a picture of the balls on this smc and I cant no even see the balls , vs a healthy one I can see the balls on the side , there is still shit under this smc I will see if I can upload the pictures
 

pcfriends

New member
i have only 1 that i buy with the balls on and the seller promise was programed already i hope he didn't lie about that lol, and i have a donor board , were i can take one.
 

pcfriends

New member
lol i fail , ppbus_3gh is now 12.3v and i have no green light and machine don't power on , stil with no green light i read 3.4v on J6900 pin 5
 

larossmann

Administrator
Staff member
When PPBUS_G3H is down by about 3-4% from what it should be, SMC is not running.

Do not get discouraged or depressed, just try again. I know. It sucks. I posted a 2 hour video of just how much this sucks.. so I know.
 
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