Help!, Acer Aspire A314-21(DA0ZASMB8D2 Rev. D) Flicker

[ary89]

Hello, can someone help?, this Acer Aspire A314-21(DA0ZASMB8D2 Rev. D), flashing/flickering LCD when brightness set to full, sometimes it changes to green, red and white screen, I think there is problem with backlight control or LCD power, I have DA0ZASMB8D0 boardview and schematic, but not real D2(14 inch), but component look similiar, I don't have osciloscope to measure voltage ripple to lvds route, but I highly suspect it must be it, can someone enlight me?

[mcplslg123]

Not necessarily LCD power related. It could be even PCH part of SOC.

Recently had a HP LA-G07XX mb with 8th gen i5 SOC and it starts flicering when brightness exceed 70%.

Tried everything but in vain and finally decided to replace SOC . Problem was solved.

ON newer SOC boards,screen flickering is more often then not a fault of PCH.

[ary89]

i suspect that too, because all the source come from APU, and out voltage from main rail 19v and 3v is all good, if need to replace those A4, it will be too costly, I still not try external HDMI yet, try it soon, if APU is bad then HDMI out must be bad too right?

[mcplslg123]

No, sections are different for internal Screen and HDMI. In your case, very likely HDMi will work flawless.

However, dont jump to the conclusion that APU is bad. I figured that after lots of investigation.

Check whether all inputs of internal screen are stable or not like BL_ON/INVT_PWM/LEDVDD etc.

The names may differ in your schematics.