My hunch is there’s DC output voltage triggering the DC protection circuitry and automatically shutting down the amplifier.
So we need to measure if there’s any DC voltage at the output of the amplifier. Note, you cannot do this check by sticking your meter at the output binding posts… because those are connected to the relay terminals — and you won’t be able to get any useful reading.
We need to measure where the RED arrow is pointing in the schematic below. (Of course, the negative or BLACK probe of our meter should be connected to Ground. There is a common ground point on the amplifier, just right below the power transformer location.)
On my last post, I have a theory that DC protection is kicking in for this Crown XLS 202 amplifier and that is what’s causing the FAULT condition.
So now, it’s time to open up this amplifier and verify that theory.
NOTE: You need star-security bits to open up the cover on this amplifier. Good thing I have some of that special screw driver heads in my shop.
They basically look like this:
On my last post, I agreed to take a look at an XLS202 power amplifier brought home by my daughter. It belongs to a friend of hers, and it needs fixing.
First, we need to know what the problem is with this amplifier. So I plug the power amp, and turned it ON. It came to life, power lights on, fans running at full speed, all LEDs also turned on, including the SIGNAL, CLIP and FAULT light, and then everything turned OFF automatically.
Okay…. So I tried turning it on again, and this time it’s dead… nada. The fan didn’t even moved. Hmmmm….
My daughter came home one day carrying a big honking Crown amplifier. It turns out it belongs to a friend of hers (who’s in a band), and it needs fixing. So I said “Okay, I’ll look at it.”
I’ve never really done amplifier repair. Much less repair a pro-audio power amplifier. This will be *fun*!
Hello all, and welcome to the *NEW* DIY-Central.com website…. 2.0.
Yeah, this site is basically a re-incarnation of my previous DIY-Central (which died of neglect). It’s where I used to post my personal electronics (and non-electronics) hobby projects and experiments back in 2005/2006? I’m grateful to say one of the projects blogged from the old DIY site turned into a side-business back in 2007 — just around the time the recession started.
As they say, if you want to kill the fun out of any hobby, turn that hobby into a business! So now, you have your regular day job, and what was previously a fun hobby you do on the side, is also now “work.”
So this *new* DIY site is my attempt to bring the fun back to my electronics hobby. On this site, I’ll be posting projects I’ve been working on, or want to work on, or stuff that currently interests me.
I’m not really talking to a specific audience here,. This is not a company blog site. This site is more for ME, my online note taking, my online build diary.
If you stumbled upon this site, and enjoy reading other people’s thoughts and adventures in their DIY projects, or looking at electronics project build pictures, or finished DIY projects, then maybe you’ll find this site interesting. If you have something to add to the discussion or topic, or have tips or additional information for the project, I’d love to hear from you guys.