QSC PLX1602 defective ribbon cables

[Mick Bailey]

There was a service bulletin for affected amps to have their ribbon cable assemblies replaced. Has anyone had success with removing the header clip, cutting the cables back and re-terminating, sealing along the cable/header with hot-melt?

[Mark Black]

Hi Mick -

The manufacturers rarely let on the base reason for failure, but my money would be on a problem with the terminating connectors themselves (as in plating issues or insufficient IDC grip due to metallurgy). As I recall Mackie had a fairly substantial similar problem over many models and ended up going to gold-plated connectors on the replacements.

Just saying a re-term using existing connectors might end up being only a temporary fix.

I once replaced all the ribbon cable connectors and header pins in a problematic Soundcraft console after determining the plating was flaking off the pins at the contact point. Luckily it was semi-modular (as in 8-channel modules) so there weren't as many connectors as in in a fully modular model.

Best of luck!

[Mick Bailey]

I guess replacement is the only long-term fix; it makes sense that re-terminating would only be temporary cure, as it would still use the existing components. Many of the amps failed within their original warranty period quite soon after manufacture and I noticed just how little grip the connectors have on the conductors - every one will break/make contact with the slightest movement.

[km6xz]

It is easier to make and replace cables than ordering new ones that will probably have the same flakiness soon after installation. I used to replace the Mackie cables with their revised cables but every version the came up were just as bad. So I bought a good selection of connectors and ribbon cable and solved the problem for good. We replaced hundreds of those ribbon cables each year and the "home" made versions finally solved the problem. I had a larger form mixer that used 37 ribbons, the manufacture wanted $287 for the cables plus $112 in shipping so I made them 2 weeks ago for an investment of 1.5 hours and $50 in cable and connectors.