Asus X555LD no video on onboad display

[A1yn88]

Hello.
I have a problem with an Asus X555LD rev. 3.3. It has video only on external monitor. I changed the LDVS tape, the screen, I put another BIOS. When I try to change the display on the keyboard I only show my external monitor, as if the internal monitor did not exist. I do not know if it makes sense to do a CPU reflow or has other problems.

[Techtiger]

Re: Asus X555LD no video on onboad display

https://www.badcaps.net/forum/showth...ht=Asus+X555LD
Downlode the Bordview and find the LDVS section find out what Voltage are missing 19v 3.3? For example

[Duranitron]

Re: Asus X555LD no video on onboad display

just a suggestion. some laptops have lcd display switch in the cmos setting try it first. reflowing the cpu will kill it specially if you don't have the proper bga reflow machine and tools. the CPU and Video ic is fine don't messed it up. just check the LVDS or place the original LVDS with the new screen make sure to put out the battery and power before connecting it. and try again..

[A1yn88]

Re: Asus X555LD no video on onboad display

Hello
Thank you for the answers.
I have boardview for v. 2.0 because for v. 3.3 I have not found, but I think are the same with regard to the location of the pins on the display. I have 19V and 3.3V. I have checked with LDVS and three-source display, including new products.

[A1yn88]

Re: Asus X555LD no video on onboad display

Hello guys, I solved the problem. The bad piece on the motherboard was ANX1121. It was stranger to be diagnosed because I was taking out all the values indicated on the boardview, but it had some internal resistance, I suspect, that failed. The luck was that an identical laptop came in service with other problems and I was able to compare it. I do not know what happened exactly but the screen was defective too.

[pecrie]

Re: Asus X555LD no video on onboad display

@A1yn88 ,

I just had a good look at the X555LD schematic in the TSIC boardvieuw.I don't have that much experience with using boardvieuw until now.

But I have noticed several indications for some objects /parts on the pcb.

For some it says PRxxxx - does it means Part Resistor (PRxxxx) ?
Others are named PJxxxx - for Part Jumper ?
And PCxxxx for Part Connector ?

Is my assumption correct ?
And I could not find the 19Volt in the NET list .

Just playing around with the boardvieuw I can see that it is a heck of a tool to find problems or voltages at certain locations

[ktmmotocross]

Re: Asus X555LD no video on onboad display

tsic is piece of crap

[Techtiger]

Re: Asus X555LD no video on onboad display

@A1yn88 ,

For some it says PRxxxx - does it means Part Resistor (PRxxxx) ?
Others are named PJxxxx - for Part Jumper ?
And PCxxxx for Part Connector ?

Is my assumption correct ?
And I could not find the 19Volt in the NET list .

Just playing around with the boardvieuw I can see that it is a heck of a tool to find problems or voltages at certain locations

PRXXX Resistor
PCxxxx capacitor
PJ for Jumper
at the beginning boardvieuw are difficult but with experience it's easy

[ktmmotocross]

Re: Asus X555LD no video on onboad display

Hello guys, I solved the problem. The bad piece on the motherboard was ANX1121. It was stranger to be diagnosed because I was taking out all the values indicated on the boardview, but it had some internal resistance, I suspect, that failed. The luck was that an identical laptop came in service with other problems and I was able to compare it. I do not know what happened exactly but the screen was defective too.

Have exactly the same problem on X553MA. did u have some measurement that prove that ANX1121 is bad, or u just replace it? Mine LCD look like bad too

[A1yn88]

Re: Asus X555LD no video on onboad display

When I tested with multimeter on diod, showed 0.040 on + 3V circuit and 0.004 circuit on + 1.2V circuit, and on the other board that I had as a reference shows about 0.387 on the same electrical circuits.

[Techtiger]

Re: Asus X555LD no video on onboad display

When I tested with multimeter on diod, showed 0.040 on + 3V circuit and 0.004 circuit on + 1.2V circuit, and on the other board that I had as a reference shows about 0.387 on the same electrical circuits.

test J4502 voltage
pin 2 3 4 36 38 39

your +3VS line is bad find the starting point of +3VS you have to trace it from there

[ktmmotocross]

Re: Asus X555LD no video on onboad display

test J4502 voltage
pin 2 3 4 36 38 39

your +3VS line is bad find the starting point of +3VS you have to trace it from there

allready checked - all ok. even all signals have its voltages

display not react, but when i connect known good lcd, its backlicht blink abou half a seconds period

[pecrie]

Re: Asus X555LD no video on onboad display

@techtiger thanks for the explanation

[Conste]

Re: Asus X555LD no video on onboad display

Also had this problem before, defective ANX 1121 chip.