Film-Tech Forum ARCHIVE: USL CM-680 - no stage channels except when corssover is in Bypass

This is topic USL CM-680 - no stage channels except when corssover is in Bypass in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Ken Lackner (Member # 1002) on 12-31-2019, 01:45 PM:

I've got a CM-680 that does not pass any stage channels except when the crossover card is flipped to Bypass mode. Because of this, I initially suspected the crossover was at fault, but if I install this crossover into another monitor, it works just fine, and another crossover or a crossover bypass card in this monitor produces the same fault. I contacted QSC about repair of the monitor, but they informed me that the unit is obsolete and no longer supported. So I figure I could crack it open and see if there's anything I can do to try to repair it myself. What's the worst that could happen, I break it even further? [Big Grin]

Anyone have any suggestions on what to look for?

(Paging Harold!)

Posted by Harold Hallikainen (Member # 5405) on 12-31-2019, 04:11 PM:

The CM-680 was designed before I joined USL. I;m working on finding a schematic. If all channels died, I'd suspect something in common to all the channels, like the power supply. I'll see if I can find a schematic!

Harold