Re: Dell E171FPb No Backlight - Test Inverter?

Does anyone out there have a schematic for the logic board OR the power supply in this unit, or perhaps even just the pinout for the connector between the two.

Knowing where to look for what supply voltages would be pretty helpful.

Re: Dell E171FPb No Backlight - Test Inverter?

The inverter actually still seems fine. With the Logic Board disconnected I can still fire up the backlights by jumping 3.2V to the On pin. I was assuming I damaged one of the other output sections of the power supply and this is why the logic board doesn't seem to be responding.

Re: Dell E171FPb No Backlight - Test Inverter?

Well I identified the On pin for the inverter (not the one with 2V, but the one with 0V, hence the inverter not turning on). By jumping this pin to 3.2V I can make the backlight come on at will. Since apparently this told me that logic board was not sending this signal for some reason I just decided just to wire in a manual switch for the backlight. While doing this I accidentally shorted between the On pin (which was also connected via a wire, to the pin on the PS supplying 3.2VDC to the logic board) and one of the pins that supplies...

Re: Dell E171FPb No Backlight - Test Inverter?

Thanks for the info Alexanna, that is helpful. Of the two "other" pins going to the inverter, one has 2.0VDC and the other 0V. A number of other pins on the logic board to power supply connector do have 3.2VDC, so I wonder if somehow the On signal to the Inverter is weak (corrosion, bad solder joint, etc). Dare I jump 3.2VDC from one of the other pins to the ON and see if the inverter fires up?


All measurements were with the display on and an image on the screen.(

Re: Dell E171FPb No Backlight - Test Inverter?

Here is the best picture I could manage. It is an Ambit inverter board, so the BenQ stuff doesn't apply, though I did check the SMT fuse....

To cut right to the point:
Is there a way I can tell if the problem is the inverter before buying a new one? The inverter is getting 25VDC, and the SMT fuse is fine. I don't measure any voltage going to the lamps, what should this voltage be? There are 2 conductors coming from the logic board that I assume are an on/off signal; any way to "jump" these on so I can be sure the problem isn't just a lack of this signal? Got a few old laptops laying around, could I harvest an inverter from one of these?

Long Version:
I have a Dell 17" display that has been...