Sony Mbx-224 case study

[aamkaachaar]

Case Study
Mbx-224 ... no power ....

No 3V / 5v generating .....

Changed .. the Regulator SN608098

Same problem...

Checked the Enable voltage.. found 0 ...

suspected i/O changed NPce783LAodx with NPCE 781 LAODX

still no enable voltage..

again suspecting I/O ...though confirmed that it will match ...but situation there
forced me to change it again ... with same part number ...

but for my badluck ....same situation again ... No enable voltage ...

then tried out with Bq24753A(bcoz some time ...Charging is cause for not generating 3.3/5v)

still no luck ....

at last while checking out ..impedence on every pin of 3.3/%v regulator .....i found 33ohms ...on pin4 and pin 5 (system_Vref )
Lifted the PC102 ( 1u /10V) the 33 ohms ...was released ...and
i said ..f*****g capacitor ate my all time ...

but fruits in end ...

here is the pic ...

[esmat-fadak]

ha ha ha
nice repair

[javed]

good sir