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Dell E207WFPc Monitor 12v Conversion

I’m still on my crusade of removing every trace of 240v mains power from my shack, so next up are my computer monitors.

I have 4 Dell monitors, of various models, hooked up to my main PC.

The monitor here is a Dell E207WFPc 20″ widescreen model. There will be more when I manage to get the others apart to do the conversion. However I’m hoping that the PSU boards are mostly the same.

Panel Removed
Panel Removed

There are no screws holding these monitors together, the front bezel is simply clicked into place in the back casing, these clips are the only thing that holds the relatively heavy glass LCD panel & it’s supporting frame! The image above shows the panel removed. The large board on the left is the power supply & backlight inverter, the smaller one on the right is the interface board to convert the DVI or VGA to LVDS for the LCD panel itself.

PSU Board
PSU Board

Here’s a closeup of the PSU board, the connector at centre right at the top of the PCB is the main power output, and also has a couple of signals to control the backlight inverter section of the PSU, on the left side. The PSU requirements for this monitor are relatively simple, at 14.5v for the backlight & 5v for the logic board.

PSU
PSU

Here’s the top of the PSU board, very simple with the mains supply on the right side, and the backlight inverter transformers on the left.

Hooked In
Hooked In

Here I’ve hooked into the power rails on the supply, to attach my own 12v regulators. The green wire is +14.5v, and the purple is +5v. Black is common ground.

5v Regulator
5v Regulator

On doing some testing, the backlight inverter section doesn’t seem to mind voltages between 11.5-14.5v, so a separate regulator isn’t required there. Even running off batteries that’s within the range of both charging & discharging. The only regulator required is a 5v one to reduce the input voltage for the logic PCB.

First Test
First Test

On applying some 12v power to the regulator input, we have light! Current draw at 12.5v is 2.65A for a power consumption of 33W.

12v Input
12v Input

There’s plenty of room in the back casing to mount a 12v input socket, I have left the mains supply intact so it can be used on dual supply.

Final Wiring
Final Wiring

Here’s the 5v regulator mounted on the back of the casing, all wired up & ready to go.

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Garmin eTrex

Front
Front

Pocket sized GPS navigator. Here is shown the greyscale dot matrix LCD.

Interface
Interface

Serial interface on the back of the unit. Pinout from left is +3v, Rx, Tx, GND.

PCB Back
PCB Back

PCB Removed from the casing. RTC backup battery in the centre of board, CPU & flash ROM on the left. GPS chipset is under the shield on the right.

PCB Front
PCB Front

Front of the PCB, GPS antenna on the right, LCD panel left.

LCD Removed
LCD Removed

LCD folded back from the PCB. Driver IC can be seen attached to the ribbon.

Electroluminescent Panel
Electroluminescent Panel

LCD Panel backlight. Requires 200v AC at 20kHz to glow green.

GPS Reciever
GPS Reciever

GPS chipset with the shield removed.