Yamaha DSP with intermittent fault

[jon]

I bought a yamaha DSP A2 secondhand. When it's working, it sounds great. It has an intermittent fault, though. When I turn on the amp (or switch the main speakers off then on using the button to switch between main speakers pair A and B) often one or other of the channels is either silent or distorted and v attenuated. Occasionally, this affects both channels. This issue affects multiple inputs, and both analogues and digital inputs.

Wiggling the volume knob up and down sometimes fixes the problem. Leaving the DSP turned on for a bit of time also tends to let the problem resolve.

Any ideas what the problem might be here? It's a nice amp aside from this, so would like to keep it...

 

[reddish75]

Dirty switch or pot?

 

[davlett]

From memory the pre out / power in phono sockets have built - in micro switches which become intermittent. A good shot of switch cleaner into the socket usually sorts the problem out. Simply plugging / unplugging a phono into the sockets also often cleans the switches

 

[jon]

From memory the pre out / power in phono sockets have built - in micro switches which become intermittent. A good shot of switch cleaner into the socket usually sorts the problem out. Simply plugging / unplugging a phono into the sockets also often cleans the switches

Thanks! I was struggling to think which of the (many, many...) inputs, switches etc. would be worth cleaning. Plugging and unplugging the metal links between pre/power a few times seems to have reduced the frequency of the problem (though could just be placebo) so seems worth trying switch cleaner on those, and maybe volume pot too. No electronics/DIY shops near where I'm living now, so if anyone could point me towards a decent buy online that'd be handy

 

[reddish75]

Deoxit d5, would be my cleaner of choice, just a tip, the volume pot looks like an alps motorised one, they are normally sealed, there's no cleaning those short of drilling little holes in each section (not recommended).

 

[davlett]

Thanks! I was struggling to think which of the (many, many...) inputs, switches etc. would be worth cleaning. Plugging and unplugging the metal links between pre/power a few times seems to have reduced the frequency of the problem (though could just be placebo) so seems worth trying switch cleaner on those, and maybe volume pot too. No electronics/DIY shops near where I'm living now, so if anyone could point me towards a decent buy online that'd be handy

When I had the same unit some years ago I used Servisol switch cleaner on the micro switches fitted to the phono sockets and didn't have any more issues, ran it for years! Its a good idea to put a plug in occasionally so that the switch gets operated and self cleans.

 

[jon]

From memory the pre out / power in phono sockets have built - in micro switches which become intermittent.

Thanks for the replies. By the way - you do mean the 'pre out'/'main in' sockets?

 

[davlett]

Thanks for the replies. By the way - you do mean the 'pre out'/'main in' sockets?

Hi Jon, yes the 'pre out / main in' sockets.

 

[jon]

Thanks again. Didn't get round to doing anything this week, and now the problem seems to have stopped. The benefits of laziness Best to give it a quick clean anyway, or leave alone if the problem doesn't return?

In terms of something to deal with crackly switches/pots (I also have an old NAD3020 that could use some attention) would this do then? http://www.images2.co.uk/Accessories/Electrical.Switch_Cleaners/SERVISOL_SUPER_10_SWITCH_CLEANER_AM600100.html?utm_source=googleps&utm_media=organic

 

[davlett]

I'd give 'em little spray with Servisol to clean the switch contacts anyway. Same with the Nad and the crackly pots / switches.

 

[jon]

Right, now have some servisol. Do I just spray onto the phono sockets, plug + unplug a few times and then leave to dry. Or something else?

 

[davlett]

Just a little spray into the pre out / main in phono sockets is all it took to cure mine.....problem never returned. A friend had the same intermittent problem on his DSP A1 ( I think ) and his is still ok.

 

[jon]

thanks - gave it a spray into each...will leave it to dry and then hopefully it'll prevent any recurrence