acer aspire 4743 no power pwm overheat help urgent

[razu]

hy friend I have acer aspire 4743 which pwm ic is over heat Ic number rt 8223 . I change the pwm new one but same, dc power supply ampare is 0.83. Its 5v coil supply is ok bu 3.3v coil is only 0.65v. but there is no short (mosfet,pf)

what can I do

mb part number is : JE- 43 MB

[HarryPK]

Re: acer aspire 4743 no power pwm overheat help urgent

what does happen when you pressed power button? previous/early

[megaraider]

Re: acer aspire 4743 no power pwm overheat help urgent

You have to find who is to blame... step by step.
If some IC is overheating it will most likely the one to blame (NOT the RT8223).
If a visual and temperature inspection does not raise any suspicions,
then you must follow a more step by step approach:
- open the jumpers after '3D3V_PWR' (remove solder)
- measure if RT8223 is outputting 3.3V:
» if not, the mosfet are likely damaged...
» if yes, you have to selectively follow the 3.3V circuit until you find the culprit...
(ALL IC's connected to '3D3V_S5' are considered possible targets! Even the WiFi card among many others. Thus removing slot inserted boards might help reducing the possible culprits)

[HarryPK]

Re: acer aspire 4743 no power pwm overheat help urgent

i agree with Mega