problem with rivera knucklehead '55

[teefus]

when going from standby to "on", channel 2 (the cleaner channel) would not work. all of the appropriate lights would work on the control panel. sometimes there was a slight wind noise in the background. footswitching to channel 1 (lead) would work and sometimes footswitching back to channel 2 would cause it to work but mostly not. the preamp and power tubes all seem to be o.k. does this wound like a relay? any thoughts? i tried channel switching using the front panel controls and this did not change anything so it doesn't seem to be the footswitch. i pulled the chassis and tapped around. ph105 is an ldr 9HTV P873 G35 201B) and tapping it with a chopstick made channel work as normal. does this seem like a fluke or time to change the ldr? thanks, craig

[ampdoc1]

I'd check the connections to and around the LDR. I'm sure they can get intermittent (seems like anything can!), but I've never heard of it happening.

[selloutrr]

Reseat contacts. Clean connectors. Does it still do this with the foot switch not plugged in? Is this the relay switching version? If so test the switching voltages and cap that stores the switching voltage.

[teefus]

thanks, this is the version that uses ldrs for switching.