TFT LCD Monitor Troubleshooting

Monitor Troubleshooting: The Basics and Simple Diagnostic Techniques

Troubleshooting problems with LCD monitors is much like troubleshooting any problem - it pays to be methodical and logical in your thinking!

Quite often - the most simple and obvious steps are overlooked and much time is wasted looking for a more complex explanation.  Recently I found myself looking at a dead monitor at a clients, only to find the fuse had gone.  Not blown - gone.  Vanished. Actually removed from the plug.  The client thought I was being silly checking it, until they saw - or rather didn't see - the fuse.

Basic troubleshooting:

1.  Determine the scope of the problem - i.e. what can we eliminate as OK - where can we narrow down the problem to?

For example: Does the monitor work on another PC? - does another monitor work on this PC? - This will demonstrate if the problem lies with the PC - or the monitor.

2. Is the problem Intermittent?

What seems to cause the problem to occur? - can the problem be made to move by connecting the suspect item elsewhere?

With intermittent faults, to show where the problem is, you have to be able to move it in order to demonstrate which part is actually faulty.  If the fault just goes away - it might well come back.  If the fault can be seen to be moved (for example a display fault occurs on two PCs - but the same monitor) - then it is reasonable to think the monitor is faulty.

3. Is it a combinational problem?

More complex are combinational problems - for example monitor 1 works on PC1 - but not PC2, while Monitor 2 works on BOTH PCs.  Is monitor 1 faulty? - Probably not.  There is most likely a different configuration on the PCs causing the different behaviour.  Since PC2 works with the other monitor, it is likely the problem can be resolved by re-configuring the PC.

In each case above, we are determining the scope of the problem by eliminating what we know is working and OK.  with the exception of the combinational problem, most issues can be quickly resolved.