XPA-7 Help

[tech49]

Hi, everyone, brand new to The Lounge so I apologize in advance if this is a stupid question or wrong place to post it! Speaking of being stupid, I grabbed by accident, a power cable I was working on (cross wired) and powered up my XPA-7 Gen 2 amp. Needless to say the breaker tripped and now my amp is dead. The only light on is the 230v light on the back. I called Emotiva Support and they nicely explained they are not servicing these amps anymore (too heavy) and instead sent me schematics and suggested the rail fuses? Or the 5 volt power supply might be bad and its a "fairly easy" fix? I noticed the amp has 2 fuses on the small pcb board - are those the rail fuses? Secondly, is it worth it to take this to a local repair shop and see what they think? I love the Amp and it worked like a champ prior to me screwing the pooch with it! Any advice would be much appreciated 🙏! Thanks!

[Ex_Vintage]

If the fuses are blow, replace them and give it a try. If you have the schematics any local shop worth their salt should be able to repair it. Unregulated power supply problems are relatively easy to diagnose and fix.

[tech49]

Thank you for the reply, I can move a few feet from the edge! Hopefully it can be repaired. Thanks again!

[leonski]

A Hot / Neutral swap? DAMAGED your amp? What pair of wires DID you swap?

Fuses should be checked WITH A METER. With very FEW exceptions.

ALL ceramic (white body) fuses should be checked with a meter. Small fuses, like 2 amps or less may fail Near the CAP and be invisible thru the glass.

OH! FUSE MUST be Removed to check. NO Exceptions.

Next? VISUAL inspection. Look for 'burned' traces or overheated parts.....they' may look 'cooked'. USE YOUR NOSE.

A repair shop? Should ask for a 'fee' to diagnose. Might be a flat rate or hourly. BUT, generally, if you go ahead WITH the fix? Fee Waived. After all, figureing out

what's wrong is usually the hard part.

There should be NO difficult to source parts. Maybe output devices if they are Darlingtons....but that's IT. Unless you destroyed a board (not likely, based on your description)

you should be OK.

[audiobill]

Maybe emo could post all their schematics and parts values online, for those that need to fix these things...,

[tech49]

Thank you leonski! My only question is are there more fuses than the two 15a 250v ones I can see on the small PCB board? Sorry for the late thanks!!

[tech49]

To clarify I had the neutral and ground crossed in the plug. Could kick myself - what you get when messing with power cables at 1am! Thanks!

[Ex_Vintage]

Dec 23, 2020 20:23:19 GMT -5 tech49 said:

To clarify I had the neutral and ground crossed in the plug. Could kick myself - what you get when messing with power cables at 1am! Thanks!

If this is a US 120V home power distribution, the neutral and the ground should both be a zero potential. In your panel box, the neutral bus should be bonded to the ground bus. There should be virtually no voltage differential between a neutral and ground for a 120v system.

[leonski]

Than the Ground Bus is connected to some kind of External GROUND ROD.....usually some big thick piece of copper 8 to 10 feet or MORE into the ground....

I'm reaching a little here, but that would appear to be the BEST place for a whole-house surge protector, shunted TO that ground connection.....where the lightning wanted to

go, all along.

Would it even make a big deal IF Hot and Neutral were swapped? Just asking here......

[leonski]

I have NO idea about additional fuses.

ONE more place might be at the input side of the main power supply. But as to where? Unplug unit and LEAVE it so for a couple hours. The Big PS capacitors can hold a charge for quite a while.

On 2nd thought? Unless you can check the big caps for discharge......DO NOT mess with any internals A shock from that section of the amp is either painful or deadly. Take your pick...