Can anyone shed any light on this?
Kit: MK190 a small stereo amp for MP3 devices.
Problem: Audio output has dropped to an almost non-exsistant level
Device is powered from 12v switched regulated supply.
IC: TD1517 with mute/standby feature
This device worked without problem for many weeks then all of a sudden, no output. If the volume and source are turned to max there is a slight output to the speakers. Only thing done different prior to this happening was accidentally plugging in a 5v regulated supply instead of the normal 12v, but that should have ad no effect so may be just coincidence.
Have done all the usual checks for continuity, solder joints and ground connections and voltages and everything looks fine. Tested power supply and tried alternative power sources (including battery) with no change.
One feature of the IC TDA1517 is a mute function which operates when the input voltage is roughly 3 to 6 volts. At 8.5v the IC should wake up and function normally. I was wondering if the problem may be connected to this ‘mute feature’ being activated by the 5v supply, but the IC is not activating once the normal 12v supply is installed.