Dell 1702FP is a really neat LCD monitor. Here are some specs:
Contrast Ratio: 350:1
Aspect Ratio: 5:4 (Regular)
Max. Resolution: 1280 x 1024
The bad thing: it has a very common problem: it fails to power on after a certain period. The marketplace is full of faulty Dell LCDs.
The good thing: the fix is very easy. All you need is to replace a capacitor, and voila! it works again. The cost of capacitors won't exceed a dollar. Considering that you have the tools handy, then your only cost is acquiring a faulty monitor...
TOOLS NEEDED: Philips screwdriver (no. 0 and 1), pliers, soldering iron, solder, utility knife...
PARTS NEEDED: Electrolytic capacitors - 2 pieces 10uF 16V (critical ones), 6 pieces 22uF 16V, 4 pieces 100uF 25V
Step 1: Go and Find a Faulty Dell 1702FP!
Well, not a very easy and quick job, but still easier than you think! If you are not willing to pay for it (like me) go and check out IT services at your school, look at recycling centers, curbside garbage bins, etc. I am sure you'll come across one. I found two only at my department! If I check the whole university I am sure I'll find dozens more...
If you are willing to pay some for it, go check ebay! You can get something ranging from $10 to $40 including shipping. Make sure you are getting the power brick, too. Otherwise you'll shell out another $15-$30 for it.
The fault description you are looking for is "blinking LEDs" and "no picture". Sharp ears can hear a soft clicking sound coming from inside the monitor, too. Make sure that LCD has no cracks, visually it looks fine, etc.
If you are overwhelmed with search results, you can narrow it with tags like "AS-IS", "BROKEN", "FOR REPAIR", "FOR PARTS" or "FAULTY"... Also, check the ones with very low bidding price/history. There are not many people looking for faulty LCDs, yet. :-)
Step 2: Diagnose BLEDS!
I assume that you got the monitor, sitting on your living room floor. Now, test it first:
Plug the power lead to the monitor. Without VGA cable plugged in, you should see three LEDs next to the power button on the front right bottom blinking randomly. Good, you diagnosed BLEDS (read Blinking LED Syndrome), a common disease plagued among Dell 1702FP LCD monitors... :-)
Here is a short video of BLEDS if you want to be sure of your diagnosis:
Same thing? Go to the next step!
Similar thing? Well, you may still want to go to the next step... Give it a run.
Step 3: Take the Stand Off!
Four Philips screws attach the stand to your monitor. Unscrew them, then lift the stand plate from bottom, and pull it back. It will detach easily...
Meanwhile have some candies around, Turkish Delights in my case, and keep your mouth sweet while working...
Don't lose the screws. Put the stand aside. Take a candy break. Candies help you think better, and you can solve problems easier! :-)
Step 4: Take the Backcover Off!
Unscrew the four Philips screws on each corner. After that you have to snap the two large snaps shown on the second photo. Then keep it pry open and move your fingers around the opening, snapping off all sides. The backcover is off now!
Step 5: Access the Main Circuit Board!
Once you take the back cover off, you'll see the steel cover that protects the main circuit board. Unscrew all little Philips screws, take the steel cover off. Now you have the main circuit board on the right, and the inverter board on the left. The inverter board supplies the high voltage for the CFL tubes.
ATTENTION - HIGH VOLTAGE: If you run the LCD with back cover off, be careful not to touch anything on the inverter board. I did it once at battery powered laptop unit and burned my finger! So, beware of the risks! No joke...
Step 6: Replace the Faulty Capacitors!
Dell used surface mount electrolytic capacitors on this monitor. They are no different than regular electrolytic capacitors, only a plastic bottom part which enables robots place components on the board.
We will start by replacing two capacitors: 10uF 16V... I heard that most of the time this replacement is enough to make the LCD work again. These two capacitors are labeled as C604 and C507. If changing these won't help, you may try to replace remaining capacitors.
Prepare your soldering iron, solder, utility knife (or something else to cut the capacitor legs short). Start heating your soldering iron...
And the capacitors! Here is the list of all electrolytic capacitors that Dell 1702FP has on board:
2 pieces 10uF 16V (critical ones)
6 pieces 22uF 16V
4 pieces 100uF 25V
De-solder the old capacitors! Polarity is printed on the board, so you don't have to pay attention to polarity when you are de-soldering the faulty ones.
Reshape the legs of the new capacitors into T figure. Trim the long legs, so you'll have legs only long enough to sit on the circuit board firmly.
Solder the capacitors on the circuit board. Pay attention to the polarity. All electrolytic capacitors come with polarity signs on them. Put them on the board in correct direction, otherwise they will blow up. Look at the last photos on this step, these are new capacitors in place.
Step 7: Test the Monitor!
Connect the power lead, turn the LCD on, and voila!
If you are in the 90% crowd, now you have a perfectly working LCD monitor. Moreover you delayed the hazardous material contaminating your environment!
Otherwise, you may try replacing the rest of the capacitors...
Still no avail? Well, life is a bitch. Sorry for the damage. :-(
Replace the covers, in the reverse order of previous steps... Be careful on the two sets of black Philips screws. The machine screws (with thinner teeth) are for the stand, the other set is for back cover. Don't mix them...