Hello,
Can anyone give me any tips on repairing a VU meter? This is a proper Ernest Turner moving coil meter, with its own rectifier. I've pulled the meter out, so buffer amp problems, etc., can be ruled out. I don't recall doing anything that might have caused damage. It used to work fine, then the unit sat on a shelf for a while, and when I plugged it in this week, one meter wasn't moving.
There's absolutely no needle response to a signal. From the point of view of the driving circuit, the meter seems normal, with a reasonable looking drop across the external 3K6, so it's not completely open circuit.
The needle moves freely, but bounces around more than expected, appearing under-damped, for example if I pick up and move the meter. My working meters don't bounce like this. Is the damping likely to be mechanical or electrical?
I don't really know what components are inside a meter like this, and they're mostly hidden behind the movement. Incoming signal first encounters a resistor on each side. The rectifier must be hidden. Is there anything else in there?
I suspect I'll have to have it apart, but while I'm not a complete sausage-fingers, this is smaller and more delicate than anything I'm used to working on. I'd appreciate any advice from anyone who has done it before. What am I likely to find, and what are the chances that I'll be able to repair it?
Steve.
Can anyone give me any tips on repairing a VU meter? This is a proper Ernest Turner moving coil meter, with its own rectifier. I've pulled the meter out, so buffer amp problems, etc., can be ruled out. I don't recall doing anything that might have caused damage. It used to work fine, then the unit sat on a shelf for a while, and when I plugged it in this week, one meter wasn't moving.
There's absolutely no needle response to a signal. From the point of view of the driving circuit, the meter seems normal, with a reasonable looking drop across the external 3K6, so it's not completely open circuit.
The needle moves freely, but bounces around more than expected, appearing under-damped, for example if I pick up and move the meter. My working meters don't bounce like this. Is the damping likely to be mechanical or electrical?
I don't really know what components are inside a meter like this, and they're mostly hidden behind the movement. Incoming signal first encounters a resistor on each side. The rectifier must be hidden. Is there anything else in there?
I suspect I'll have to have it apart, but while I'm not a complete sausage-fingers, this is smaller and more delicate than anything I'm used to working on. I'd appreciate any advice from anyone who has done it before. What am I likely to find, and what are the chances that I'll be able to repair it?
Steve.