Asus x550l display problem

[thinkfast76]

I have a strange problem with an asus x550l.
show on external screen but no signal on its led.
I would like to test the LED fuse. can anyone tell me what it is?
i have the border view

[Techtiger]

Re: Asus x550l display problem

check J4501 LDVS connector
pin 29 30 31 for 19V AC BAT SYS INV CON
pin 27 for 3.3V BL EN
pin 5 & 11 +3VS
report back

[on/off]

Re: Asus x550l display problem

I notice that part for supply LVDS seem all connected directly:

• JP4503 for 19V (jumper pad)
• SL4504 for PANEL_VCC (seem coil)
• SL4501 for +3VS (seem coil)

Maybe related problem on U4501
Refer the boardview with x552 schematic, quiet close i think. Just click x552

[thinkfast76]

Re: Asus x550l display problem

Thx a lot guys, i will report tomorrow

[thinkfast76]

Re: Asus x550l display problem

So i check....
JP4503 for 19V (jumper pad) 1,89v
SL4504 for PANEL_VCC 18v
SL4501 for +3VS 3,21

But i I saw that jumpering pin 11 and pin 12 of j4501 the monitor produces an image but without backlighting

[on/off]

Re: Asus x550l display problem

So i check....
JP4503 for 19V (jumper pad) 1,89v
SL4504 for PANEL_VCC 18v
SL4501 for +3VS 3,21

But i I saw that jumpering pin 11 and pin 12 of j4501 the monitor produces an image but without backlighting

Seem not correct???
why 19V be 1.89V
panel vcc come from +3V_EDP be 18V?? double check your measurement

[thinkfast76]

Re: Asus x550l display problem

Seem not correct???
why 19V be 1.89V
panel vcc come from +3V_EDP be 18V?? double check your measurement

ok,l will check again,sorry for this.

Can you tell me why if you jumper pin 11 and 12 the image appears but without backlight?
Thx a lot for your time

[thinkfast76]

Re: Asus x550l display problem

ok,l will check again,sorry for this.

Can you tell me why if you jumper pin 11 and 12 the image appears but without backlight?
Thx a lot for your time

Then measuring the voltages, on j4501, everything seems ok except on pin 10 and pin 27. On pin 10 measure 2.14v on pin 27 0V. Checking in the circuit I saw that the only component in common between these 2 pins and R4530, also measured this on pin 1 always 2.14V.
I think the problem is U4501 that at pin 5 always measures the damn 2.14 not enough to power the screen. In fact, bridging on j4501 pin 10 and pin 11 (which from 3.14V) the panel turns on but without backlighting. So I think the pin 27 feed the backlight and pin 10 the screen. Tips?

[Techtiger]

Re: Asus x550l display problem

Test U4501 pin 20 for 3.3V PANEL VCC 3.3V if you have 3.3V on that pin test all the components related for that SL4504 SL4522 C4512 C4517,
R4530 is your BL EN & PANEL VCC
Test U4501 pin 44 for 3.3V BL EN test all the components related for that

[thinkfast76]

Re: Asus x550l display problem

Test U4501 pin 20 for 3.3V PANEL VCC 3.3V if you have 3.3V on that pin test all the components related for that SL4504 SL4522 C4512 C4517,
R4530 is your BL EN & PANEL VCC
Test U4501 pin 44 for 3.3V BL EN test all the components related for that

I will try thx a lot

[hezareh2000]

Re: Asus x550l display problem

hi, request bios asus a550ldv rev 2.0
thank you