[SOLVED]820-3787 No Image

[G.Beard]

No visible damage.
Liquid, no.


Starts and chimes (nice long dong).
No image to internal screen or external monitor.
Backlight working, lights up.

 

[arghhh]

What if you remove the SSD? Will it go to missing OS icon after a few minutes?

 

[G.Beard]

What if you remove the SSD? Will it go to missing OS icon after a few minutes?

Yeah, that was the first thing I tried was to remove SSD, plug external drive (my test drive) and hold alt key for boot options... Nothing.

PPVCORE_GPU is 0.85V is that right? I don't have a working board to test

 

[Sykulski]

PPVCORE_GPU should be 1V :-(

 

[G.Beard]

What if you remove the SSD? Will it go to missing OS icon after a few minutes?

I have seen bad SSDs cause blank screen and would not boot from anything while the drive was on the board. I assume then a similar problem on the board could do the same.
I notice that the external drive LED is not flashing as it does on all good machines I have plugged it into.

I have be through a laborious process and tested everything around GFX / GPU power and everything reads OK.... Completely at a loss! No fucking idea where to go from here.

Any guidance please?

 

[arghhh]

If you have GPUVCORE_EN, then remove L9330 and L9360 and then inject 1v onto PPVCORE_S0_GFX_REG with a power supply and see if it works, if not then fucked.

 

[dukefawks]

GPU Vcore at 8.5V seems unlikely, check again.

 

[G.Beard]

GPU Vcore at 8.5V seems unlikely, check again.

heh, yes of course. 0.856V
Changed it above too

 

[dukefawks]

If backlight work a bad LCD is the first suspect.

 

[G.Beard]

If backlight work a bad LCD is the first suspect.

Tried unplugging screen already and connecting to internal monitor.
If not screen and not connector, maybe mux?... BUT...

The machine is not actually booting as the keyboard does not light up, there is no sound when entering the wrong password after leaving the machine to boot for 5 minutes.
Controller on the SSD is uncomfortably hot to touch, can't keep fingers on it. If you wanted to test for a fault on the SSD circuit where would you start?

At this point I would like to try and rule that out as I think it could be causing blank screen same as as bad SSD can do.

 

[dukefawks]

SSD controller gets hot, normal. Disconnect everything from the board and test with a known good LCD assembly.

 

[G.Beard]

Fresh new screen, no different.
Tried eternal monitor again, no different.

 

[dukefawks]

Can you do a PRAM reset?

 

[G.Beard]

Can you do a PRAM reset?

Oh FFS... I don't even need to say it do I?
I swear it didn't work before.

 

[dukefawks]

So we can call this fixed?

 

[G.Beard]

Much to my embarrassment, yes it works.

Thank you for your time.