Sony mbx-247 need to remove battery to turn on (sometimes not)

[flc1988]

Hi, i have a Sony vpceh-30eb. Battery original looks good. Original charger Sometimes, when pressing the power button, the notebook does not light up any led. but if you remove the battery it turns on normally. Sometimes it runs on battery power.

[mon2]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

This often means that you have a leaky mosfet onboard in the power path from the power adapter and the battery mosfet. That is, when powered by the power adapter, it has the priority and the battery mosfet should remain OFF but the battery should charge. If the adapter is removed, only the battery mosfet should be enabled to power the logic board.

Would you have a schematic for this unit? If yes, post it in the schematic forum and link it here. Do not post the schematic here.

1) Attach the known good and suitable power adapter (only) - remove the battery. This setup should power on the logic board everytime.

2) If the schematic is not available, review the DCin connector and locate the mosfets in this area + charger IC that is onboard. Post clear pics of this region so we can try to reverse engineer the logic board.

[flc1988]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

Tanks for help-me. See the schematic.

[mon2]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

Attach the power adapter. Remove the battery.

Meter in dc volts (30v or higher) scale.

Power on. Carefully measure the voltage to ground of each pin on mosfet pq32. This is the battery mosfet and it should only be on if the battery is the only power source.

Post your measurements.

[mcplslg123]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

Have you looked into protection circuit? Sony is notorious for protection circuits.

[flc1988]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

Gate to earth - 18.75v
drain to earth - 0.17mv
source to earth - 18.80v

[flc1988]

Re: Sony mbx-247 need to remove battery to turn on (sometimes not)

About this ?