Vostro 5471 no picture, fans on full

[BeHeX]

Hello
I have a problem with my laptop. The fan itself starts for literally a second, or on another BIOS it is constantly at full speed and nothing else happens, any hints?
Vostro 5471 laptop
Service Tag: 8F74C02

[Stevedb]

Re: Vostro 5471 no picture, fans on full

Does the caps lock toggle on extern keyboard.. to see if it post. Did you do a clean me region of your bios before flashing.

[BeHeX]

Re: Vostro 5471 no picture, fans on full

the external keyboard does not work at all as if it does not supply electricity, while the flash drive in the same usb normally shows it works. so i cleared the ME region..

[mcplslg123]

Re: Vostro 5471 no picture, fans on full

Your mb is not posting for sure. USB port will have 5V power after switching the mb-thats why you feel flash drive as working . USB keyboard's numlock light will glow when posting.

[rediii]

Re: Vostro 5471 no picture, fans on full

give us measurements of the coils pls

[BeHeX]

Re: Vostro 5471 no picture, fans on full

i check the coils and think are fine.

[SharkeyJoe]

Re: Vostro 5471 no picture, fans on full

Check if the laptop is giving a LED diagnostic code (blinking amber+white LED on left side of laptop). If so, see manual on Dell website for a table that gives the meaning of the different codes (Example: 2 amber+4 white). The issue may be as simple as needing to re-seat the memory, or replacing a bad memory stick.

Be aware that, after fixing the issue, the laptop may need to put itself through several on-off cycles before it manages to POST. Be patient and give it a few minutes before deciding that the fix didn't work.

It's easy to confuse the codes, so count the blinks carefully.
It's possible to fix one LED code only to get another, So keep a careful watch for changes in behavior.

[Sephir0th]

Re: Vostro 5471 no picture, fans on full

i check the coils and think are fine.

Still, voltage resistance to GND measurements of the coils please. Especially the ones related to the CPU and to +1.2VS.