Help identifying component on main board of Acer KG281K monitor

[VitalComputing]

Hi All

This component is from the main board of an Acer monitor. I've been fighting this monitor all day and I refuse to let it beat me! Can anybody identify what this component might be?



I have 20V on the input side of the component and nothing on the capacitors on the other side of it. Does it look damaged or does this component have two markings???

thanks

[lotas]

Re: Help identifying component on main board of Acer monitor

Sy8253adc

[VitalComputing]

Re: Help identifying component on main board of Acer monitor

Thank you.

What mistake did I make - I googled the name on the IC and got nothing? The hole in the bottom right is damage, right?

[SMDFlea]

Re: Help identifying component on main board of Acer monitor

Thank you.

What mistake did I make - I googled the name on the IC and got nothing? The hole in the bottom right is damage, right?

what model number is this acer monitor ,and the main board part number ?
.

[VitalComputing]

Re: Help identifying component on main board of Acer monitor

ACER KG281K Monitor

Picture of the main board below

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

You have 4 pin. (EN) Enable control is there tension?
And what is the resistance on 6 pin. regarding gnd.?
Most likely this is the power output to the panel.

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

You have 4 pin. (EN) Enable control is there tension?
And what is the resistance on 6 pin. regarding gnd.?
Most likely this is the power output to the panel.

Below are the voltage measurements on the six pins of the IC. I can't get a reading from pin 1.



Resistance between pin 6 and ground is 0.472k ohms. I checked for shorts to ground on all IC pins and the only one that is short to ground is pin 2, which is the ground pin. I think I'll just source a replacement IC and install.

[R_J]

Re: Help identifying component on main board of Acer KG281K monitor

Pin 4 ENable pin is low, so the ic is turned OFF, this pin needs to be above 1.5v

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

You don't have a 4 pin enable command. (Enable) and because of this, there is no output power to 6 pin.
R_J got ahead of me.

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

For diagnostics and experiments, it is better to disconnect the LVDS cable from the panel (so as not to burn the matrix).

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

I've cleaned off the chip and that was just a bit of dirt above pin 3, not physically damaged like I first thought. So it does seem that the issue is with the chip not being enabled, rather than the chip being damaged.

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

What is wrong with the monitor? (It does not turn on, does not respond to button presses, the standby indicator does not light up ...).

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

Original owner said that monitor didn't work after a power outage.

When I plug the monitor in, the blue power light comes on, but nothing comes on the screen and no backlight. Even though the power light comes on, it does not turn off when I press the power button on the button panel. I've checked the button panel and there is 3.3V on all buttons, which is grounded when I press each button.

I've disconnected the main board and on PSU board jumpered the ON/OFF pin to 5V (using a resistor) and the backlight comes on. The PSU schematic says that the two main voltage rails should be 5V and 16V, which measure 5.1V and 15.15V respectively on my board.





No short or blown fuse on T-con board. And the main board acts the same way with the LVDS cable connected or disconnected. I'll do some more work on the main board later. I'll see if I can find where the enable pin for that XT7YC goes and work out why it is not switching on.

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

Rather, the SPI Flash firmware has flown.

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

Something I didn't see where you have 3.3v on the board, measure if the voltage on the flash is 8 pin.

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

I was in the process of marking out all the voltages on the board in Photoshop when I discovered that that section of the board had no voltage on it and started troubleshooting there. I will complete the full list of voltages across the caps and inductors on the whole board and upload later. The 3.3V is present on the button panel, so I am sure I will find it on the main board also.

I think I'm trouble with this one. Don't seem to be able to source a replacement main board either. It's listed on a site in the UK that I have dealt with before but they have no stock available.

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

Here are all the voltages measured on the main board.

I found two shorted components on the second HDMI port (marked by the white arrows), which I removed. Was hoping that might bring it back to action but no go.
I'll try more tomorrow.

[VitalComputing]

Re: Help identifying component on main board of Acer KG281K monitor

You don't have a 4 pin enable command. (Enable) and because of this, there is no output power to 6 pin.
R_J got ahead of me.

I jumpered the 3.3V to the enable pin and that brought 12V online on the output but still no go. I think I may just try source a main board.

[R_J]

Re: Help identifying component on main board of Acer KG281K monitor

I suspect the microprocessor is not outputing the control signal, this may be due to a corrupt eeprom. If you have a source of cold spray (or inverted canned air) You can try freezing U402. Remove power to the board, freeze ic, then apply power and try to turn on.
Might be worth trying?

[lotas]

Re: Help identifying component on main board of Acer KG281K monitor

Here are all the voltages measured on the main board.

I found two shorted components on the second HDMI port (marked by the white arrows), which I removed. Was hoping that might bring it back to action but no go.
I'll try more tomorrow.

If there were short-circuited components at the HDMI input, then most likely the discharge slipped through this input and killed the processor.