Peavey Media Matrix I/O power supply issues

[SSLtech]

For over a decade now, I've been servicing systems with Peavey Media Matrix processors and I/O modules.

Handy systems which work as well for for dubbing theaters (installed two systems) as they do for hotel distributed audio applications.

Until now, apart from PC computer-based systems, where computers get old and have to be replaced, the only issues I've really had have been with the SMPS modules in the audio I/O 'breakout boxes' (analog gateways on and off the Cobranet system).

I've previously just thrown in a replacement power supply, which has the same manufacturer (EOS) and part number as the original. (There are two versions; basically one with plus and minus 12V, the other with plus and minus 15V, in addition to each having a 5VDC@8A output.)

Anyhow,  I just had three turned in for repair, with the usual 'dead SMPS' symptoms. I ordered four new power supplies, and 'borrowed' a supply from a fourth used-but-working' module I have in storage.

The 'borrowed' unit powers up the module it was put in, but the new replacements (new, sealed from a major distributor) don't power up the two other units. If you unplug the load from the DC side,m they fire up, but with the load connected, the units behave as if they're in some sort of 'protection' shut-down.

Swapping the 'borrowed' used PSU into any of the three interfaces makes the interface work. The two brand-new power supplies won't make any of the three units function.

Before I try and source a large dummy load to test all of the PSUs, does anyone have any suggestions?

Keef

 

[JohnRoberts]

Sounds like a faulty run of PS modules... OR they changed the design. The fact an old standard PS works OK is bad news for the new ones.  Of course check the part number/spec to make double sure it is the right model.

Perhaps bench test a new PS module and see how well it starts under full load...  There could be some marginal soft start, foldback current limit funny business, while it isn't your job to reengineer their commercial PS.

Do they (the PS mfr) have any kind of customer service contact?

You can always ask Peavey, their customer service is pretty good, while I doubt they build much in MS any more, they probably still do final assy packaging on big ticket items like media matrix in meridian so might know if there is a known new PS weirdness  issue .

JR

PS: Hi there  ;D

 

[SSLtech]

Hi John! 

Thanks. Yes, I'm going to grab another couple of working units and re-verify that the new PSUs behave differently to more than one old unit... indeed, they are the same manufacturer, same exact model number.

The only contact I see on their web site for the USA is one sales guy, shown as being for the Western US region.

After that, I'll be digging up some low-ohm, high-watt resistors.

Keith