Troubleshooting my (non-working) OR15 head — Help!!!

[Rocker&Writer]

Folks,

Just looking for a little technical guidance here, as repairing and troubleshooting amps isn't my specialty.

My Orange OR15 head (plugged into an Orange 2x12 cab) just stopped working suddenly at band practice the other day. It was working great for about 2 hours, I put it on standby to go to the bathroom, came back... and nothing. The display light comes on, but there's no sound whatsoever. Not even a hum. I tried all the obvious things: different cables, plugged my guitar into a another amp, hooked up another head to my cab to make sure it wasn't the cab, etc.

I had the same thing happen when I first bought an OR15 two years ago. At that time Orange said it may have just been an anomaly and they sent me a replacement, which worked fine until now. This time, the folks at Orange told me to change the fuse, which I did, and nothing changed.

What could be the issue here? Again, this isn't my area of expertise, but from what I know tubes going dead wouldn't cause a complete and sudden death like this, right? Anybody have any ideas what I can/should try before I haul it off to a pricey repair shop?

Rock on,

Ben

[a.hun]

What could be the issue here? Again, this isn't my area of expertise, but from what I know tubes going dead wouldn't cause a complete and sudden death like this, right? Anybody have any ideas what I can/should try before I haul it off to a pricey repair shop?

Rock on,

Ben

It could, depending on which valve died. Or could be a fair number of other things.
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Andy.

[Rocker&Writer]

Thanks, Andy. I appreciate the help.

My issue right now is that I'm in the final month of my 2-year Orange manufacturer warranty. So I'm trying to get to the bottom of whether it's a relatively minor issue I can/should handle myself (fuse, tubes, etc.) or some catastrophic problem that requires me to enlist an authorized Orange repairman.

[Les Paul Lover]

Thanks, Andy. I appreciate the help.

My issue right now is that I'm in the final month of my 2-year Orange manufacturer warranty. So I'm trying to get to the bottom of whether it's a relatively minor issue I can/should handle myself (fuse, tubes, etc.) or some catastrophic problem that requires me to enlist an authorized Orange repairman.

There's only one thing you can do - change all the valves/fuse.

Order a full new set, swap the valves one at a time and try it again. Ensure you have a good fuse in there too. That way, you should be able to find out which valve died, and which old valve can be kept as working spares.

If you replace the power valves (el84) ensure you eventually replace both. If you've been practicing with it regularly, they are probably tired anyway.

My bet would be on one of the el84s. Preamp valves Can go anytime too, but typically can last 4 to 5 times as long as power valves.

Beyond the valves, everything is tech time really. And since your valves only have a 90 days warranty, you might as well eliminate them as the issue.

[NobleKnight]

Ben,

I have an OR15 and had the same issue. I've had mine since August of 2016. It's a great amp, so I was pretty bummed when it just stopped working one day. Power light came on, but absolutely no sound.

I contacted Sweetwater where I purchased it from and they helped search for a similar fuse. I purchased the one the sales person and myself found online, but it blew the second I installed it. It was supposed to be slow blow, but it evidently was not. It has a fine hair thin filament. I later learned that when the amp first powers on there is an initial surge that the fuse has to absorb before it levels out. I spoke a local amp tech and he pointed me toward a local electrician's supply store and I gave them the specs and it worked. The bussman fuse I purchased had a noticeably thicker fuse filament and was definitely slow blow. In the meantime, I had called Sweetwater back and they also sent a couple of Orange approved fuses on their way to me in the mail. The 250mA fuse that worked was a BUSS Fuse model # S506-250-R.

I also changed out all of my tubes because the power amp tubes typically cause the fuse to blow when they start to become faulty. I also wanted to upgrade the set and purchased Mullards from the TubeStore. After these two updates, the amp works great and no problems at all since then.

I hope this helps because I had a hard time locating someone to help point me in the right direction.

Rock on!
Shane

[langmurf]

I had the same type of problem with my TTHW. Put new fuse in and it would blow immediately. Took to Orange USA (local, lucky for me) and turned out to be a wonky PI tube that was oscillating or something. New PI tube fixed the problem.

And, gotta say, Orange support is top shelf.

[pedecamp]

Thanks, Andy. I appreciate the help.

My issue right now is that I'm in the final month of my 2-year Orange manufacturer warranty. So I'm trying to get to the bottom of whether it's a relatively minor issue I can/should handle myself (fuse, tubes, etc.) or some catastrophic problem that requires me to enlist an authorized Orange repairman.

If you replaced your fuses with no success, next plug your guitar directly into the return on your fx loop, if you get sound then you know your power tubes are good, if no sound then there's your problem. If your power tubes are good then get a single 12AX7 and try it in each preamp position until you find the bad tube. If still no success then its tech time.

One thing worth doing first before doing any of the above troubleshooting is reseat all your tubes to eliminate the possibility of a bad connection.