Fixing my little Dell LCD.. my first ever PCB repair...

I recently bought a second hand Dell LCD monitor to go with my FTP server.  I just wanted someone small and cheap that could be used every now for maintenance etc.  I went on Ebay and managed to pic one up for about £15.  Not bad I don't think for a 15" LCD.

After using it for a few days I noticed that it would flicker on and off.. sometimes off then never back on again.  If I jiggled the power lead around at the back I could hear a crackling sound.. not a good sound to hear.. arcing electricity etc.

I decided to have a go at fixing it, the fact moving the lead around causing the monitor to start/stop I was hopeful it wasn't going to be anything too drastic.

Firstly, find a nice fluffy/thick towel to lay on a flat surface.  You'll be resting your monitor against this whilst you're working on it and dont' want to scratch/dent the LCD panel.

To remove the back of the monitor, you firstly need to remove the stand.  there are 3 small black screws visible at the rear, take these out, then ease and plastic cover off with a screw driver.  You will find a 4th (gold) screw here.  Remove that, then the stand should come away from the bottom of the monitor.

 

Next remove the 3 black screws that run across the bottom.

Then you need to pop the rear away from the front of the monitor.  The line you can see around the edge of the monitor is where the two parts separate.  Slip the two clips at the bottom apart then be brave and ease the two sections apart.

You'll find that a small ribbon cable will run from the front section of the monitor to a lttle PCB containing the brightness/menu buttons.  Just disconnect the plug on the PCB side and then put the front of the montior to one side.  Rest the lcd panel face down on to the towel and pull the rear of the monitors case away.

Next remove the 8 gold screws that run around the metal cover then remove, you'll see across the top of this metal cover that there are little metal clips that the top lip of this cover slides under.

Now you can see the PCBs for the monitor.  You can see that the power lead connects to the PCB on the left.  Disconnect the ribbon connections as with the button panel from the case.  Then remove the 2 screws.
The PCB will now slide away from the chassis like the previous metal cover did.

Looking closely at the soldered joints on the rear of the panel I could see a little carbon ring around one of the pins on the power socket.  This as well as dull solder is a sign that the joint has failed.

A soldering iron with a fine point is generally the best idea for repairing PCB's as its a lot neater and reduce the risk of soldering across 2 joints.  A little bit of solder later and the joint is nice and shiney and ready for putting back together.  Before completing I sprayed contact cleaner across the whole PCB just for luck.

The picture above shows the power PCB removed, note the right hand panel has a ribbon connector at the top. This pushes against a sponge insert attached to the rear case panel.  This will often disconnected when removing the rear panel so make sure you reconnect if before putting back together!

For putting back together, literally do the reverse of what you did to take it apart, I found it easier to place the frame section of the cover of the case on the towel, then rest the LCD panel on top before cliping the rear back on.