Recent content by Jimboradley

No audible sound when light goes on. I can't remember if I ever noticed a click before, but that's definitely a great lead to follow. Thanks!

Whoops sorry. I wasn't very clear there. Under normal operation, the light starts red, then turns green after a few seconds and the amp starts making noise. On my amp with no output, it still starts red and goes green. It doesn't stay red or go back to red. So I don't think it's detecting any...

Oh interesting. I found the user manual online and it's got this snippet: If the Backline unit senses any unsafe operating conditions, the output signal is immediately muted and the power light changes from Green to Red. However the power light didn't turn Red, so maybe that's not the mode...

Fair criticisms. I had some electronics classes in college but am by no means an expert. Enough to identify most of the components on the PCB and steer clear of the caps, though. I don't think the head is worth paying to repair. I may just toss it or sell it for parts. My biggest concern is...

Yes tried both. The BL600 is 1/4" only. The Ashdown cab has the combo jacks

Based on this simplified schematic, it's got to be either in the boost/GIVE circuit or power amp. If I can figure out how to test the XLR direct out (when post is switched) I can narrow it down further

I think the cab passed the 9 volt test. Supposed to sound like someone plugging an instrument cable into their bass while the amp is on? I think that also exonerates the speaker cable too then. By process of elimination, it's got to be in the head.

No continuity between tip and sleeve at either end. Connecting effects-out back to effects-in doesn't change anything

Right. That makes sense. So I understand it should be 6-7 ohms, but measures somewhat high. Is that concerning? Would that put suspicion on the cab being defective? Or is 7.8-7.9 within the normal tolerance?

Heh. Not a fan of contact cleaner? Ok I'll skip that part. You seem to really know your stuff.

Yes speaker cable has continuity on both tip and sleeve. Resistance of the new cab is 7.8-7.9, which I guess is a little high for an 8 ohm cab?

The PCB for the jacks looks really clean, but I'll spray it with some air and put some contact cleaner on it when I get a chance. Plenty of dust on the main PCB so that may be a contributing issue. Resistance on the new cab is just under 8 ohms, which is what I would have expected if you hadn't...

I'm 95% sure I didn't do this. I generally try to be very careful with new stuff

Yes speaker cable (though I haven't tried a different speaker cable yet, don't have a spare lying around I phrased that badly. The old cab is just a cab, not a combo. I meant the combination of head and cab that have been tried and true for years.

So, I just got a new cab, an Ashdown ABM-115H-EVO IV-PRO NEO 1x15". 300 W, 8 ohms. I plugged it into my GK Backline 600 (300 W at 4 ohms) that I've had for years with a 1/4" cable into the speakon dual jack. As far as everything I've read this should have been fine. I played it for a while. It...