Toshiba Satellite S50-B-14Z / No Image

[nrcslim89]

Hello all, here goes my first thread hope we can deal with this issue together and fix this machine.

I have here an Toshiba Satellite S50-B-14Z.
And the issue goes like this:
- I pull the power button, the machine turns on, but when she must or try to load BIOS screen and start normally,
- The LCD don't do retroilumonation and it's possible to see with an light pointed to screen an tentative of LCD start,
- LCD show a totally black screen without any logo of toshiba and in 2 seconds that black screens goes away.

The machine still working with retro illumination at keyboard, if you click on CAPS or NUMLOCK they show activation light on keyboard.

So I opened the laptop and checked that BIOS chip has been "touched" by someone without any skills, I remake the solder points and resolded the chip... Seems all fine and continuous mode of multimeter indicates the points are in contact.
But the issue still here...

Could anyone help me to discover what I need to check please?

Thanks for all

[Techtiger]

Re: Toshiba Satellite S50-B-14Z / No Image

So you are trying to say laptop starts but no backlight but the image is DIMM do you get the image on external screen ,did you can connect with HDMI , upload a image and mother board number

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

Hey there, thanks for your reply,
Yes laptop turn on, but don't present any type of image, just for a 2 seconds of a total black image without light and after that 2 seconds lcd seems to get off again like there's no connection.
On external HDMI port nothing too...
I will upload the part number of machine and motherboard ID.

[Techtiger]

Re: Toshiba Satellite S50-B-14Z / No Image

Dissemble the motherboard upload both sides pic , you can do some basic stuff Remove memory remove the bios battery no adapter inserted not even the battery hold down the power button for 10 seconds, Power of the mob and see

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

Laptop Info:
Toshiba Satellite S50-B-14Z
PART NO: PSPQEE-00200KEP

Motherboard Info:
A000302600 WFKF03
DABLIDMB8E0 REV:E

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

Ok, i already remove the battery.
Hold power button for more than 60 sec.
Theres no removal BIOS battery to get off.
Already try to change RAM Memory...
Already tried to only turn on the board with HDMI external LCD, RAM and stll the same.

[Techtiger]

Re: Toshiba Satellite S50-B-14Z / No Image

For this MB That schematic is available,I have upload a picture of the MB test all Big Gray Coils for Voltage with the help of the multimeter

[KvnTM]

Re: Toshiba Satellite S50-B-14Z / No Image

You mentioned that someone has touched the bios rom. Make sure it is the correct chip and reflash the bios.

Verify that the chip is W25Q32
Make a dump of it and post it here
Flash a new bios bin.

This all sounds like a bios issue to me..

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

For this MB That schematic is available,I have upload a picture of the MB test all Big Gray Coils for Voltage with the help of the multimeter

I will verify, but could you please say me what should I verify on multimeter?
Just continous mode ?
Resistance mode ?

Thanks

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

You mentioned that someone has touched the bios rom. Make sure it is the correct chip and reflash the bios.

Verify that the chip is W25Q32
Make a dump of it and post it here
Flash a new bios bin.

This all sounds like a bios issue to me..

Yes, it seems to be resoldered by another one... i will verify chip ID and post here.
But please could you say me how i could reflash BIOS without an programmer ?
I am waiting for CH341A programmer at moment...
What do you suggest ?

[KvnTM]

Re: Toshiba Satellite S50-B-14Z / No Image

Yes, it seems to be resoldered by another one... i will verify chip ID and post here.
But please could you say me how i could reflash BIOS without an programmer ?
I am waiting for CH341A programmer at moment...
What do you suggest ?

Do you have an Arduino ?
I use one as my primary flashing tool. Works great.

You have to use an external programmer. There is no way around since the board is "not working". Either the CH341 or Arduino one.

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

I only have a raspberry pi 1
Maybe couldnt do the job.
OK first I will check for coils, there's nothing I can lose, I will wait for Ch341a, Theres no way to flash it with a USB pen with recovery mode??

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

By the way, what arduino model you suggest?

[KvnTM]

Re: Toshiba Satellite S50-B-14Z / No Image

I only have a raspberry pi 1
Maybe couldnt do the job.
OK first I will check for coils, there's nothing I can lose, I will wait for Ch341a,

Never done it with a raspberry but there's probably a solution for it. Google is your friend.

Theres no way to flash it with a USB pen with recovery mode??

No.

By the way, what arduino model you suggest?

I just use a cheap Arduino uno clone which I converted to 3.3v. You can get those for cents from the Chinese markets

[Techtiger]

Re: Toshiba Satellite S50-B-14Z / No Image

I will verify, but could you please say me what should I verify on multimeter?
Just continous mode ?
Resistance mode ?

Thanks

First in Voltage mode write down all the voltage's then in Resistance mode

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

Thanks for all support, I will do tomorrow the suggestions, when i have all data I will report here for you.
Thanks once more.

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

For this MB That schematic is available,I have upload a picture of the MB test all Big Gray Coils for Voltage with the help of the multimeter

Did you know the value I need to have?

[Techtiger]

Re: Toshiba Satellite S50-B-14Z / No Image

Did you know the value I need to have?

Some of the Coil Value

[nrcslim89]

Re: Toshiba Satellite S50-B-14Z / No Image

Some of the Coil Value

Thanks once more,
Now i have been verified the continuity of the coils, most of them are fine, they do the continuity and no short to ground at all.
But, theres one of them thats in short to ground in the two sides of the coil.
Plus... I have two capacitors doing short to ground and they are in the same rail of the coil they come right before of coil, they are:

PC826
PC981

So i test like this, without charger or battery pluged in, i tested the two shorted capacitors in resistance mode with black probe at GND and red probe on Positive side (dot) of capacitor of capacitor and i have this values:
PC981 - 011.4Ohm
PC826 - 011.5Ohm

The coil is next over the capacitors and like i said they are shorted to GND and i assume that is:
PL802 and i have in one side 011.8Ohm (capacitors side) and on another side 07.82kOhm (mosfet side).
Hope you could help me... could you point me an link or attach the schematic please i would like to understand the schematic too.

Thanks

[KvnTM]

Re: Toshiba Satellite S50-B-14Z / No Image

Thanks once more,
Now i have been verified the continuity of the coils, most of them are fine, they do the continuity and no short to ground at all.
But, theres one of them thats in short to ground in the two sides of the coil.
Plus... I have two capacitors doing short to ground and they are in the same rail of the coil they come right before of coil, they are:

PC826
PC981

So i test like this, without charger or battery pluged in, i tested the two shorted capacitors in resistance mode with black probe at GND and red probe on Positive side (dot) of capacitor of capacitor and i have this values:
PC981 - 011.4Ohm
PC826 - 011.5Ohm

The coil is next over the capacitors and like i said they are shorted to GND and i assume that is:
PL802 and i have in one side 011.8Ohm (capacitors side) and on another side 07.82kOhm (mosfet side).
Hope you could help me... could you point me an link or attach the schematic please i would like to understand the schematic too.

Thanks

If PC826 & PC981 are on vcore rail 11Ohm would be fine. CPUs and GPUs have a very low internal resistance.

PL802 and i have in one side 011.8Ohm (capacitors side) and on another side 07.82kOhm (mosfet side).
Thanks

Whats the resistance of the inductor itself? Both sides should have about the same resistance to gnd.