Toshiba L50-B-1Q0 (Main DABLIDMB8E0 REV:E) no power on

[robgerr]

Good morning forum. This laptop comes into my laboratory with the defect that it won't turn on. By connecting the bench power supply I have an absorption of 1.56A (battery charging), I disconnect the battery, I have an absorption of 0.01A. I give the power on but it doesn't react. I check the mainboard and I notice the Isl88732 charger with oxide and a little burnt between pins 7-8. I remove the charger, clean the pads and solder another ISL coming from another identical board. I also find a bit of oxide in the power button connector. I clean the connector, clean the flat that goes to the power button, connecting the power supply I find the 3.3v on the power button pins which drop to 0v when I press the button. I tried to flash two bios downloaded from your site, also reprogrammed with the official Toshiba one which I cut since it was bigger but nothing to do. Even the small 24xxx spi but nothing. I didn't find short on the main coils.
I only have the 3.3v and 5V voltages.
ISL88732: (no battery connected)
pin 1 5v
pin 2 3,93v
pin 3 3,18v
pin 4 0v
pin 5 5v
pin 6 0v
pin 7 1,42v
pin 8 0v
pin 9 3,34v
pin 10 3,34v
pin 11 3,34v
pin 12 0v
pin 13 3,34v
pin 14 0v
pin 15 1,33v
pin 16 0v
pin 17 1,25v
pin 18 0v
pin 19 0v
pin 20 0v
pin 21 5,09v
pin 22 18,68v
pin 23 1,23v
pin 24 1,20 with little oscillation
pin 25 4,77v
pin 26 5,09v
pin 27 19,20v

[mon2]

Would you have the link to the schematics? Post the link only if the schematic is in the schematic forum.

Are you sure of this part number (ISL88732) on your charger IC? This is an AC voltage based charger IC.

[robgerr]

Hi Mon2 and thanks for replying. I downloaded the schematic but I don't remember where. I'll send you a photo of the oxidized component IC charger replaced (picked from other same main board)

[mon2]

Ok. Can you post a partial view of the schematic that shows this charger ic. Even better if you post the full schematic in the schematic forum and link it in this thread.

[robgerr]

This is the schematic I found, but unfortunately it doesn't match serigrafy.
https://www.badcaps.net/filedata/fetch?id=2052989