Back lit Working Pictures NO ( Picture working only with Ex. Screen)

[dlshad96]

Hi Mates

I have three Laptops backlit Working with internal Screen . But Data-Pictures-Images NON

with external Screen both are fine

i tried replace the chip of BIOS ,change the LED screen,DATA Cable, same problem .

Thinkpad L530 15.6"

Thinkpad E520

Toshiba C660-LA-6842P

I need your Help Guys

Thank you in advance.

[caspian]

Re: Back lit Working Pictures NO ( Picture working only with Ex. Screen)

measure voltage on all pins of the screen connector on the mainboard, and report them here. Then, we can help.

[dlshad96]

Re: Back lit Working Pictures NO ( Picture working only with Ex. Screen)

Thank you for replay

L530 is 40 pins

1,8,9,10,11,12,13,14,15,16,17,17,18,19,22,23,24,25,26,27,28,28,30,31,32,33,34,37= 0V

Pins 20 and 21 = 1.5, 1 V

2,3,4,6,7,35,36 = 3.3V
38,39,40 = 20V

[dlshad96]

Re: Back lit Working Pictures NO ( Picture working only with Ex. Screen)

if i dont press the power button ( tourn ON the the laptop ) only last 3 pins 40,39,38 = 20V others non

[alvin24705]

Re: Back lit Working Pictures NO ( Picture working only with Ex. Screen)

if i dont press the power button ( tourn ON the the laptop ) only last 3 pins 40,39,38 = 20V others non

check signal BL_ON# (Backlight_ON signal)

[caspian]

Re: Back lit Working Pictures NO ( Picture working only with Ex. Screen)

Unfortunately, I did not found the schematics file of L530.
If you upload it here, it would be possible to have a better troubleshooting.
according to your measurements, your laptop is not sending data to the internal screen.
Probably the GPU or PCH is faulty. but I am not sure without schematics.