820-3588 not turning on.

[BCN_Techs]

Got this with "explosion" in C6300-C6305 area. IT was burnt. Cleaned and replaced all componentes . Short is gone but still not turning on.

CHecked all S5 rails and they all are ok. Not getting All_Sys Good and PP1V01_S0 is shorted to ground or near to short ( 50Ohms.).



Whant else can i check?

 

[BCN_Techs]

Autoreply. U6300 is making board not turning on. When it is removed, board start normally, when i put back new or old U6300 it doesnt turn on.


Also checked pin by pin if there is any short but only GND pins are shorted all other are ok. Will try with another new chip ( from donor) and back with answer.


both ic.s are SSM3302 the only difference is that original is SSM3302 A#309 and donor is SSM3302 A#244 , does it matter?

 

[2informaticos]

Did you check both 12V_S0 and 3V3_S0 rails, when U6300 is on the board?

 

[BCN_Techs]

12V0 with u6300 on board is beginning go up very slowly from 0 V, now after 2 minutes with power supply connected i have 1.8V and growing. 3V3_S0 is 0V.

 

[2informaticos]

I was thinking about diode mode readings...

 

[BCN_Techs]

Diode mode of 12 and 3.3 V on U6300?

 

[2informaticos]

Yes, to see if the audio chip pulls-down any.