Reply To: merc o tronic 98

[mic57]

The first two items to check are the vibrator and the 10 ohm potentiometer. Over the years the contacts in the vibrator can become dirty or corroded. The unit can be carefully disassembled and cleaned. The potentiometer is also a point of failure due to dirty or burned contacts or wiper. Schematics for these units are difficult to find. Here is a link to a discussion of the 9800 on the Smokestack forum that you may find useful. https://www.smokstak.com/forum/threads/merc-o-tronic-9800.125077/