Welcome to the Dell Community  @rollano 

Sorry but you may already know that @Chino de Oro 's methode will not work.

"If your Dell computer shipped before December 2015 and is listed below, then it supports BIOS Recovery 1."

https://www.dell.com/support/kbdoc/en-us/000132453/how-to-recover-the-bios-on-a-dell-computer-or-tablet#faqs

And your model is not listed.

First try the "BIST" test first.

Hold down the "D" key, push the power button, release the power button, wait 2-3 seconds and release the "D" key

The laptop should go through an LCD test of solid White, Red, Green, Blue and Black 2 or 3 times.

After completion it should try to automatically boot 2 or 3 times.

Have you tried to "Shotgun" the system?

Remove evrything you can except one known good memory stick.(For booting)

https://www.dell.com/support/manuals/en-us/precision-m4700/dell_precision_m4700_om-v2/removing-and-installing-components?guid=guid-7aaae6e7-9d06-4c20-82bf-728abc2df3ef&lang=en-us

Remove all other memory, HDD's, main battery, CD/DVD etc.

After "Shotgunning" removeing everything you can try to boot.

If the system boots then one of the devices you removed is bad.

Replace one device at a time and try to boot.

If the system does not boot then that device you just replaced is bad.

If the system does not boot afetr removing everything then the system board is bad.

Best regards and good luck,

U2

Waw, thanks.....holding down the "D" key, really does the LCD test (exactly how you did write), but booting did not follow. The M4700 after test still runs maybe another 6 sec. and then shuts down like always before.....Now only led which are on (first three from left / first - disk led blinking (but i have three disk inside SSD 2,5,HDD and M2), battery led (but my battery is completely dead) and wifi.....I will try to remove components ......

Nope....i did remove all three disks, both RAMs (then one return), WIFI, battery, Bluetooth, 3V battery,  jumpers (which i did find) except power one and keyboard (for D key)......then perform again LCD test, which did go trough, but no any kind of booting......any difference (maybe M4700 did stay up few second longer with black screen after LCD test).......  is there any way to know, if BIOS file is corrupted and then just recover or flash.......because to me (i don't see any problem inside), after start up both fans are running, keyboard working, led are on......

Edited to remove non-working method of BIOS recovery.