Yamaha dsp a1000 left channel cuts out sometimes in surround mode, sterio works fine

The easiest way is to buy the new part online and replace it - cost about $50US.

However, if you're up to it, this problem is fixable without the need to buy any parts. The selector switch has four sets of spring contacts which need to be bent slightly to increase the pressure on the pads against which they press, but it's a tedious job and not for the faint-hearted.

Here's what you need to do:

Open the case (6 screws) and also free up the front panel (9 screws).

You'll see that the switch consists of a PCB, an aluminium box and a motor. Remove the two screws holding it to the front bulkhead. take oyr the small "L" shaped circuit board that overlays it. A plastic pop-in holds the bottom of the switch PCB and the switch assembly can then be removed entirely.

Next you will need to remove the aluminium switch box from the PCB. Firstly de-solder all the connections which hold it in place. Now pull it clear.

Here is the MOST critical part of the job: inside the switch box you'll see four circular plastic wafers - these contain the contacts you need to fix and you'll need to bend the tangs which hold the shaft assembly onto the housing and then the tags which are holding the wafers in place. Your difficulty will be making sure that the wafers go back on the shaft with the rightr alignment and that the wafers go back in the same order.

Take some digital pictures while the wafers are still on the shaft with the orientation of the KNOB included - if you mess this up (I did) the job becomes horrible! Also, mark each wafer with a number 1-4 because there are three different kinds Once you are comfortable that you can replace the wafers in the proper rotary configration with respect to the shaft, remove them individually and pop out the gray plastic cores and bend the spring contacts upwards so that they will go back pressing more firmly against the pads. Now reassemble, and good luck!

Hi, Your luck is in. This is a small problem but it might be hard to find. You need to look for a Dry joint. This will sitting either on the front panel or on the output stage of the left channel that is going mad. I would suggest that you have a look at the front panel first. Also clean your selector switch just in case.