Hi,

A customer brought in an A1989 logic board that is in a boot loop.
It chimes and the backlight flashes briefly and does it all over again. The CPU gets warm as do the SSD, U2800 and UB00. It let me rebuild bridge OS sucesfully in DFU mode with no change.

All USB ports get 20v and go up to 0.456ma and then down again in the loop.

The board is clean, there are no signs of liquid damage or corrosion. The customer said it just wouln't start one day for no reason.

Some of the voltages I checked are as follows:

PP3V3_G3H...

Re: Need help reading schematic for Toshiba motherboard

Good Morning budm,

I tested between PVBAT and Ground, if I am correct on my ref.point and get 28.29K
Please check my ref point as I am not sure if it is correct.
Please see photo.
Thanks again for taking time to help....

Re: Need help reading schematic for Toshiba motherboard

budm,

It does not turn on with battery and no ac adaptor.
I do get much heat on the large chip to the right on the detail photo. (I'm not sure of reference number)
DC Voltage on the Gate pin 4 of Q6012 with good batteries connected is 18.1vdc

Re: Need help reading schematic for Toshiba motherboard

selldoor,

Please find revised photo with additional coils.

I was getting zero volts on L6100 and L6150 I reversed my test leads with Pos on the pos Pos in terminal, and neg on the coils and got 19.2vdc....

Re: Need help reading schematic for Toshiba motherboard

budm,
I am getting Positive 19vdc at at fuse 6000, COIL L7600.
I am using an alligator clip on gnd through holes on MB.
The VCC pin of the U6000 pin 20 = Pos 18.9vdc
The reverse polarity applied was 19.5vdc, (I did it by mistake with a wrong adaptor on a universal charger when it fell off.)

selldoor, I attached photo's with some details as you suggested, fuse 6050 is Pos 3.1vdc

aanan, Pos 19vdc at 6000, COIL L7600

I will upload any other details and follow your...

Re: Need help reading schematic for Toshiba motherboard

aanan,
I get 19v past fuse 6000 and coil L7600, in fact I get -19v and +3.1 @ battery connector.

selldoor,
Fuse 6050 is showing +3.1v I will post pics and notes tomorrow, I am away from the mb.

I appreciate you guys helping!

Hi,

I have a L855-11K Toshiba with this MB DK10FG-6050A2491301-MB-A02. The power was applied with reverse polarity and now their is no power lights. I am getting voltage up to the battery terminal but only 3.1v
I downloaded the schematic but I am noob at reading them.
Could anyone with experience direct me to the component that would have been damaged, or the section I should be focused in the schematic. I am not seeing any burned out Mosfets or diodes and both fuses test ok.
I am getting a pulsing reading of 7.x and 8.x vdc out of Q6010 and Q6011 Mossfet's...

Re: Dk10fg-6050a2491301-mb-a02

Hi,

I have a L855-11K Toshiba with this MB, (DK10FG-6050A2491301-MB-A02) The power was applied with reverse polarity.
I downloaded the schematic and it is the correct one but I am noob at reading schematics and it is very confusing. Could anyone with experience direct me to the component that would have been damaged? I am not seeing any burned out Mosfets or diodes and both fuses test ok. I don't understand the schematic as the voltage is not listed.
Thanks in advance.