Troubleshooting an Allen & Heath Saber Series board

Hey everybody!

I got hired to tech out a studio's Allen & Heath Saber Series board. It's the large 40 channel recording version with bar graph meters. When they power it up the peak lights come on and no sound gets through. After looking through the manual they had I noticed that it called for an RPS4 power supply, but the studio that I'm working at is using an RPS2 power supply. :roll: I can't seem to find any information on the RPS2, but just from the model number, I'm assuming this isn't enough power for this large board, but I'm not absolutely sure. I do know however that if I put 24 or less channel strips in it it works great! :grin: This validates my assumption that the RPS2 was made for a smaller board of some kind.

So, the questions are...

• Is the RPS2 enough power?
  If I need an RPS4, where the hell do I find one???

Thanks!
~Dave

hmmmmm. sounds to me like your overworking the PSU, pulling too much current perhaps. Maybe run a second PSU if possible or get a correct PSU. Has it worked before If so then check the PSU itself. might need a recap or parts replaced...

Step 1 in ANY electronic fault-finding procedure: Assure yourself of the integrity of the power rails.

-Have you measured the DC to see what is actually happening?

Why buy one? -BUILD one.

Acopian, Power-One, International Power...

You only need to bulk-up on the ±18V (or 17V or whatever it is on the Sabers... I forget, but we had two of them for a while) rails. the 48V will be fine.

Couple the outputs together with diodes, then adjust so that they both share the load.

Dassit.

Now go and MEASURE. -And DON'T leave it in a "one-rail-only" condition for long.... decoupling electrolytics tend to get reverse-biased that way, and then you need a re-cap and a lot of repairs cleaning uYou have to balance the downforce with cooling corrosive spooge from the circuit boards...

Keith

Keith

You also need to know if it worked at one time with the power supply you have. If it did, then there is probably something wrong with one or more of the modules that is affecting the supply. Substitute modules until you find the bad ones. As Keith said, your meter is your friend.