If it came into my shop I would start by reseating the RAM one chip at a time in each of the slots. Use a multimeter and test the AC magsafe adapter for output (actually I would switch the AC adapter to a known good one). Next test the DC IN port. Then remove the battery and hard drive and test them independently, trying to start the machine with each change. This one is a just a search process and without a spare hard drive, magsafe port, battery, RAM you may be in over your head. I would advise that if the RAM test fails, AC is OK, Magsafe is OK, then take it to a qualified tech.
If it came into my shop I would start by reseating the RAM one chip at a time in each of the slots. Use a multimeter and test the AC magsafe adapter for output (actually I would switch the AC adapter to a known good one). Next test the DC IN port. Then remove the battery and hard drive and test them independently, trying to start the machine with each change. This one is a just a search process and without a spare hard drive, magsafe port, battery, RAM you may be in over your head. I would advise that if the RAM test fails, AC is OK, Magsafe is OK, then take it to a qualified tech.
If it came into my shop I would start by reseating the RAM one chip at a time in each of the slots. Use a multimeter and test the AC magsafe adapter for output (actually I would switch the AC adapter to a known good one). Next test the DC IN port. Then remove the battery and hard drive and test them independently, trying to start the machine with each change. This one is a just a search process and without a spare hard drive, magsafe port, battery, RAM you may be in over your head. I would advise that if the RAM test fails, AC is OK, Magsafe is OK, then take it to a qualified tech.