While individual component repair is best left to professionals, system diagnosis is often better accomplished in the home by the user. Approach the problem in a logical fashion. Never assume the problem can't be caused by:

Chose one:

Spouse

Self

Dog

Bird Seed prices fell in the Tokyo market.

Assumptions will blind you.

In general the most valuable test equipment is your ears, and the "gray matter" between them. After that, a good set of headphones will allow any component with a headphone jack to be observed in isolation.

For our purposes your system is a collection of interconnected "black boxes." Each box has a function such as "play a tape", "play a compact disc", etc. We don't care how the box accomplishes this function, only that it does or does not function. If the box does not function, take it to your service professional. But how do we determine which box is at fault? "Elementary, my dear Watson."

Each box has inputs, such as power (or batteries), compact discs, cassette tapes, or signals from another box. Each box has outputs, such as signals for another box or, in the case of a speaker, sound. Finally, each box has controls which may modify or possibly inhibit the function of the black box. Once we determine that the box has all necessary inputs and that none of the inhibiting controls, such as the power switch, is in the wrong position, the box must be giving its output, or it is broken. If none of the boxes is broken (a common occurrence), then the problem is in the interconnections. If only one channel is working, that's great! Why? Because we know that one channel is working. We can use the working channel to diagnose the bad channel!

As an example, let's start with a simple problem -- we hear a buzz on certain notes at moderate loudness while listening to a compact disc. We will analyze the problem by studying the system performance as we systematically change component interconnections.

Here is how we would approach such a problem:

1. Always turn off the system before disconnecting or reconnecting components.

2. Using the BALANCE control, listen to LEFT only, then RIGHT only.

   Result:

   Buzz only on the right.

   Conclusion:

   Everything in the left channel is working just fine.

3. Disconnect, interchange, and reconnect the left and right speakers. Repeat Step 2.

   Result:

   Buzz on the left.

   Conclusion:

   Left speaker (originally the right speaker) is defective.

   
   
   

Analysis:

In Step 2 we determined that everything in the left channel was OK. We divided our problem in half. Systematically we want to substitute items from the right channel into the functioning left channel. When the left channel stops working, we've found a defective item (formerly connected to the right channel). In this example we were lucky and caught the bad speaker on the first trial.

For the sake of discussion, let us reconsider the above example, if the problem had remained in the right channel at step 3.

Step by step from the beginning:

1. Using the BALANCE control, listen to LEFT only, then RIGHT only.
   
   

   Result:

   Buzz only on the right.

   Conclusion:

   Everything in the left channel is working just fine.
   
   

2. Disconnect, interchange, and reconnect the left and right speakers. Repeat Step 1.
   
   

   Result:

   Buzz on the right.

   Conclusion:

   Both speakers are OK. (Note that a problem in the right speaker wire cannot be ruled out at this time.)

3. Interchange left and right from the CD player at the back of the receiver.

   Result:

   buzz is still on the right.

   Conclusion:

   defective receiver or right speaker wire.
   
   

   Analysis:

   We knew from Step 2 that the speakers were OK. If there had been a problem with the CD player right channel, the problem would have moved to the left channel in Step 3. Therefore, by elimination, the problem must be in the receiver or right speaker wire. Conversely, if the problem had moved in Step 3, all we would know for certain is that the receiver and speakers were functional and that the Compact Disc, CD player or its cables had a problem.
   
   

4. Interchange left and right speakers at the back of the receiver.

   Result:

   buzz is still on the right.

   Conclusion:

   defective receiver.
   
   

   Analysis:

   Only two possibilities were left. We already knew the right speaker was OK. When we connected the known good left speaker and speaker wire to the right channel, everything but the receiver's right channel has been eliminated.

Elementary!

Cables and especially the plugs at the end of the cables cause trouble. Intermittent cables can be frustrating to find because the problem may vanish while you are attempting to swap channels. When this happens swap a cable with one from another box. A written log of swapping activity will help keep track of what you have already tried. If one unit stops being intermittent and the other starts being intermittent after you swap a cable, you've found your problem. We could relate countless "war stories" about wasted "no problem found" trips to our service center caused by simple to diagnose cable problems.

While it seems simplistic and does not exhaust all of the possibilities, this swapping approach is effective more than 98% of the time. Be smart and play the percentages.

Note: Don't forget to restore all the connections to their original state after you've finished testing.

You may be aware of an eight to ten second delay between turning on the power and hearing music. Coinciding with the first sound is a quiet mechanical "click" coming from the "Protection relay," inside the unit. During the delay period your unit is performing a self diagnostic. If you can hear this "click", with or without music, be 95% assured that nothing is wrong with the receiver. Look elsewhere, possibly for an incorrect control setting.

Not all units have a protection relay and nothing should be assumed about the quality of your unit based on the presence or absence of a protection relay. If present, the protection relay can be a valuable diagnostic tool.