Troubleshooting

[lcaillo]

While it is beyond the scope of these forums to provide detailed help with specific troubleshooting, I can point to some places where you can learn a lot. One of the best is Sam Goldwasser's FAQ which contains this area related to troubleshooting techniques, tips, and equipment.

http://www.repairfaq.org/sam/tshoot.htm

[lcaillo]

Getting started with troubleshooting a problem involves observation and understanding. One must understand the problem and the conditions under which it is occurring. More information is always better, and careful observation is the first step.

Some devices will give error codes or flash LEDs in a certain pattern to help identifiy a problem. Some problems only occur under certain signal conditions, with certain resolutions, on certain inputs, etc. If a device is working, it is a good idea to try many different modes to see what works and what does not. With displays one of the easiest checks is to see if OSD (on screen display) or Menus work. Is sound present? In CRTs are the filaments lit? All of these are quick checks that an experienced tech will do without a thought, but might not be obvious to the user. Whether you are having a problem professionally serviced or DIYing, more information can help to get to a solution faster and at a lower cost.

If a unit is dead, the first place to start is with the power supply. Most modern units use a switching power supply. Is it running? If there are no secondary voltages, you can assume not. If there are secondary voltages, you can be confident that the regulator and controller are running. There may be a feedback or regulation problem, or some other startup issue. Some devices use a separate standby supply and some run standby circuits off of the main switching converter. Identify how the power supply is configured first, then determine if the unit is really completely dead or in some shutdown or protect mode by identifying which supplies are present and which are not.