Roland JC-120 Chorus amp

[kpinks]

Hello, I have owned 2 of these awesome amps. This is my second one. For some reason the amp cut-out at one of my shows on the weekend. After doing a bit of trial and error, it appears to be the guitar input jack on the amp. The jack is intermittent. Is this something I can fix or is it better to take to a tech? Is the amp difficult to take apart? Has anyone else experienced this problem? What would the most likely cause of this be?
Thanks

[DrGonz78]

The most likely causes can be a dirty jack, a worn out jack or a wire that needs to be soldered better. Basically, you need to take the chassis out and put it up on a table to have a look. At that point just look at the wiring to see if one or more wires are loose and/or lacking good contact. Plug in and out of the input jack while observing what is happening to the jack. Clean the areas where the plug make contact with the jack. If you have a an ohms meter test to see if you have good continuity on all connections and be sure to wiggle wires around to see for a short.

Taking apart that amp is not that bad, but it has 4 really long screws holding the chassis to the cab. Setting the speaker side facing down on a blanket is a good way to place the amp as you will be able to get it out safer that way. Just got to open her up and start looking at the input. Getting to the jacks should be easy.

P.S. Not necessarily a reason to bring it to a tech for just something simple. You can easily trouble shoot the fault and replace these simple parts(if it is just a bad input jack). Just take pictures or draw out wiring on the jacks before you do any removal. When I worked a similar model JC60 the ground wiring had come loose from one of the input jacks. If it is an older model you can bet it has wear and tear on the jacks, or typically the high gain jack.