Marshall MGDFX100 & 30DFX please help

[GForde]

My son and I have 2 marshall amps MGDFX100 & MGDFX30 and both have intermittant output.

When used with Guitars the output levels seem to change/switch up and down and break up for no apparant reason.

Both amps are relatively new ( less than a year old). We live in the Seychelles where the power supply is unreliable but both amps are protected from surge. I did a quick check of supply voltage and it is low. It averages around 207-210v. It's difficult to tell if this is having an effect but I would appreciate any comments guys. It's difficult to get gear out here and this stuff got shipped from the uk at great expense.

Thanks in advance

[techineer]

This sounds like oxidation of the normalling switches on the effects loop jacks. If you live on an island with salt air, it's a good bet to be the cause.
See the article at Preston Electronics

Start by obtaining a can of Caig DeOxit D5. (Do NOT substitute. You need an antioxidant - not a cleaner.) ( DeoxIT® ) Follow the instructions in the article about modifying the spray tube and shoot a bit of stuff in the jacks, then work it by inserting a plug several times. If it's been heavily corroded, it may take a few treatments.

While you're getting the D5, also get a can of FaderLube ( DeoxIT® FaderLube, #F5S-H6 ) to treat the controls.
(Note: I have no affiliation with Caig. It's just amazing stuff!)

Good luck!