Issues with Mackie Micro 1202 Mixer / Flashing Meter Lights?!

[velocity kendall]

Hi folks,

I have a Mackie Micro 1202 mixer which seems to work fine, except that the meter lights for the main output seem to flash on and off when the output volume reaches a certain point.

It's fine for the first 3 or 4  bars until it reaches around -7db, then it lights start to flash. They're still reading the output properly; when i turn the output volume all the way up you can clearly see the meter reading fine, it's just that the lights flash on and off roughly twice every second.

Any ideas what the issue might be?

Thanks in advance.

[Pete66]

The LED meter works with LM339 comparators. I would switch them around and see if that makes the LEDs flash at something other than -7db.  If it does then one of the LM339's is bad.  I would swap U2502 with U2501 fist to see if that changes anything.  If it does I would just replace both of them. 

Also,do you have headphones plugged in?  Does it sound fine when using headphones?

[Audiorepair]

Does the Rude Solo LED flash at the same rate when operated? 

The LED section has its own ground return to the power supply, maybe this is bad?

[velocity kendall]

Hi pete66,

I'll try that, thanks.

Yeah, all sounds fine, no problems at all. Just the blinking led meters :0/