Asus vg248qe purple light problem

[Rennokas]

Hi

I have a faulty Asus vg248qe monitor which when powered on has no OSD or picture from any of the ports. I see that Windows identifys the display, but thats it. Power button/led is purple, not sure what that means, never seen on other displays.

I opened up and dont see any capacitors being bad or any other visible defects.

Heard it is a common problem with this model, but have not seen any solutions. Anyone dealt with this issue?

[kasfamily]

Re: Asus vg248qe purple light problem

Hi!
We need to update the firmware flash and eprom

[Rennokas]

Re: Asus vg248qe purple light problem

Hi!
We need to update the firmware flash and eprom

How to update the flash the firmware and eprom? I suppose it is not the same as driver update.

[kasfamily]

Re: Asus vg248qe purple light problem

You need to have a programmer, firmware, unsolder the chips ( possibly replace them with new ones ) , and update the firmware using the programmer

[Rennokas]

Re: Asus vg248qe purple light problem

You need to have a programmer, firmware, unsolder the chips ( possibly replace them with new ones ) , and update the firmware using the programmer

Alright. Is it possible that it happened because there was a short circuit ? Previous owner of the monitor tried to fix something on the main board. (the part where the power board connector is). One SMD capacitors was short circuited and other one just fell off when I opened up the monitor. So I measured and resoldered them correctly.

So I gotta get a programmer then. any suggestion of which one?

[kasfamily]

Re: Asus vg248qe purple light problem

Of course, first you need to check the compliance of the voltages 5/3, 3/1, 8. Well, show a photo of the damage site

[Rennokas]

Re: Asus vg248qe purple light problem

Added some pics, the C420 and C433 (red circle around) were the ones that were short circuit / missing.

[Rennokas]

Re: Asus vg248qe purple light problem

I suppose the EPROM ones are the 2x 24C02RP chips on the last pic?

[lotas]

Re: Asus vg248qe purple light problem

I suppose the EPROM ones are the 2x 24C02RP chips on the last pic?

This is the eeprom EDID, most likely the spi and eeprom are on the back side.

[Rennokas]

Re: Asus vg248qe purple light problem

This is the eeprom EDID, most likely the spi and eeprom are on the back side.

On the back side there is one 24C16RP

Added pics of the other side aswell.

[Rennokas]

Re: Asus vg248qe purple light problem

Wanted to add that Windows 10 sees the display as "generic PnP". I was able to update driver from device manager to the latest from Asus site.

[kasfamily]

Re: Asus vg248qe purple light problem

U8 marking ?

[lotas]

Re: Asus vg248qe purple light problem

On the back side there is one 24C16RP

Added pics of the other side aswell.

24C16RP is an eeprom, there is 25L1606 next to it, this is an SPI flash in it and the monitor's firmware is located.

[Rennokas]

Re: Asus vg248qe purple light problem

U8 marking ?

U7 is 24C16RP
U8 is 25L1606E (or smth, last letter is somewhat faded)

[Rennokas]

Re: Asus vg248qe purple light problem

24C16RP is an eeprom, there is 25L1606 next to it, this is an SPI flash in it and the monitor's firmware is located.

How to get the latest firmware? On Asus site there is a driver with .inf, .icm and .cat files

[lotas]

Re: Asus vg248qe purple light problem

if there is a programmer, then you need to unsolder U8, read the contents from it (dump) and save, then write this dump.

[Rennokas]

Re: Asus vg248qe purple light problem

if there is a programmer, then you need to unsolder U8, read the contents from it (dump) and save, then write this dump.

Should I check voltage ? Seems like pin8 is VCC and pin4 is GND

[lotas]

Re: Asus vg248qe purple light problem

between 4 and 8 pin. should be 3.3v

[Rennokas]

Re: Asus vg248qe purple light problem

between 4 and 8 pin. should be 3.3v

Seems like it does not get 3.3v on between 4 and 8. It gets only 0.19v

[lotas]

Re: Asus vg248qe purple light problem

Seems like it does not get 3.3v on between 4 and 8. It gets only 0.19v

What is the voltage across these chokes?
And what is the resistance between gnd. If the capacitor is short-circuited, the dc-dc converter U402 could burn out.