Lenovo E520 - Low 3., and 5V ALW

[ktmmotocross]

Hello have this Lenovo E520 that have low 3.3 and 5V ALW voltages. i read 0.36V and 0.67V

cannot find datasheet of this ic BD95280MUV-GP, but everything looks good. no short, REG voltages OK, EN voltages OK, no heating.

It looks like something tells this oc to make that low voltages.

Have anybody some hint what can make this ic make low voltages on this rails?

[ktmmotocross]

Re: Lenovo E520 - Low 3., and 5V ALW

i find datasheet if this ic

https://cdn.badcaps-static.com/pdfs/...4a00b1e17e.pdf

[ktmmotocross]

Re: Lenovo E520 - Low 3., and 5V ALW

Pin 16 and 18 have no voltage

[ktmmotocross]

Re: Lenovo E520 - Low 3., and 5V ALW

sry bad reading. have no REG1 and REG2

[ktmmotocross]

Re: Lenovo E520 - Low 3., and 5V ALW

replaced ic and all works

[SMDFlea]

Re: Lenovo E520 - Low 3., and 5V ALW

You must have had internal short or something.

Vo1 (27 pin) This is the output discharge pin, and output voltage feedback pin for frequency setting. When the voltage is beyond 4.4V from the external power supply during operation, it supplies REG1.