MX-3640N wont boot

[Néri]

Hi, English is not my native language but I hope you understand.
I have an MX-3640N that wont boot, display is black just some fan starts and the little green LED on the control panel is flashing.
I have changed SD card, CF card, MFP pwb, LSU mother pwb, DC pwb, scanner control pwb and HDD, but still no go.
I tried to change the pwbs one by one and all at the same time, but still no go.
The only difference I got during the test is with the new MFP pwb not even the fans will start. I tried an emergency update and got result OK, but the machine will still not boot in normal mode.
There is 4 LED lights on the MFP pwb and all 4 is solid light on, according to the manual it means "Main process - Reus ASIC trouble" does anyone know what that means?
With the old MFP in only LED no1 is flashing, according to the manual it means "Memory check error - Memory trouble".

I will be thankful for all the tips ant tricks

//N

[mansart]

Go to Emergency Update Mode

From Op panel use "UP" "DOWN" to scroll through ROM levels.

Look for PCU versions

In the U.S. the list shows a couple ROMS as "unusual" they are the "DANI ROM", "GRPHC ROM" and "HELP", this is normal

I'm betting when you get to the PCU levels you will see that there is no ROM level listed

Replace PCU board

[Néri]

Go to Emergency Update Mode

From Op panel use "UP" "DOWN" to scroll through ROM levels.

Look for PCU versions

In the U.S. the list shows a couple ROMS as "unusual" they are the "DANI ROM", "GRPHC ROM" and "HELP", this is normal

I'm betting when you get to the PCU levels you will see that there is no ROM level listed

Replace PCU board

Hi mansart,

Thanks for your replay.
I do see the ROM lvl for the PCU pwb, but i did change the board anyway but still no go.

When Im looking through the circuit diagram I think it might be the CF card even though I changed it once.
The first I things I changed was the SD card and the CF card, I think I might have a shortcut in the old MFP pwb and when I put in a new CF card on the old MFP pwb it somehow got burnt.