No sound from TH30 (updated with pics and new details)

[Invin]

So I went to turn on my TH30 today, and suddenly there's no sound on either channel. It was working perfectly just yesterday. Here's a list of points I've noted and checked thus far:

- Light still comes on
- No sound on either channel
- No sound on 2 or 4 output tube settings
- Tested with multiple guitars and cables straight into the amp, no pedals, no FX loop, no footswitch, just guitar > amp > cab > plugged straight into the wall socket (also tried different wall socket for the heck of it)
- Replaced both HT and mains fuses with brand new correct replacements, no change
- Checked cab wiring and tried known good speaker cable

Updated:

- Replaced phase inverter and FX loop tubes with new ones, no change
- Replaced all power tubes with new matched set, no change
- Replaced all preamp tubes with new ones, no change

It seems strange that this literally happened overnight with nothing plugged in. Any other ideas? I'm not sure what else to try at this point.

[Invin]

Updated: The problem seems to be related to the HT fuse socket. Out of other ideas, I was inspecting it with a flashlight and spotted what appears to be some corrosion and scratches, and a small metal tab laying completely loose at the bottom:









I purchased the amp used, so for all I know it may have been messed up and just barely holding together until now.

When I tried the new fuse, I thought it felt a little weird, like it wasn't inserted all the way (insert dirty joke here, I know). Out of other ideas, I tried turning the amp on very low volume and gently pressing the fuse housing (black plastic insert that holds the fuse) in, and sure enough I could hear sound again. I didn't want to mess with it further with the amp on, so I unplugged everything and tried to get the fuse to stay in place, but I've had no luck; it just seems loose. I suspect the metal tab I found was there to hold it in or complete the connection. I may try a slightly longer spring in the fuse housing (the one that sits behind the fuse and pushes it into the connector) and see if that holds it snug.

There are no guitar techs anywhere near where I live, so hopefully there's a solution that doesn't involve opening the amp up, as I know not to do that. If anyone has dealt with a loose fuse connection before, feel free to chime in.

[sizzlingbadger]

Replacing the fuse holder is a simple job. It may even have spade connectors on the inside which means you won't even need a soldering iron. You will have to make sure the amp is safe to work on though, a simple multi-meter to check there is no high voltage on it before you start.

If in any doubt though take it to a tech or any electronics service centre should be able to change the fuse holder.

[Invin]

Replacing the fuse holder is a simple job. It may even have spade connectors on the inside which means you won't even need a soldering iron. You will have to make sure the amp is safe to work on though, a simple multi-meter to check there is no high voltage on it before you start.

If in any doubt though take it to a tech or any electronics service centre should be able to change the fuse holder.

I'm handy with soldering, but I've never been trained in checking for dangerous voltages (nor do I have the equipment) so I don't see myself opening it up without doing a lot of research first and getting the right tools. Unfortunately there are no techs or electronics service centres out here; I live way out in the sticks I'll have to weigh my options if I can't fix it from the outside I suppose.

[Invin]

Update (solved):

After giving up on getting it directly from Orange, I finally got a replacement fuse holder in the mail today from British Audio Service. Thankfully the metal tab I found broken off was actually mounted to the external piece that holds the fuse, not the part inside the amp. So it was as simple as putting the fuse in the new holder and inserting it as normal. Here's what the holder should look like (note the two flimsy metal tabs sticking out, which are what broke off the old one)



A question for anyone else who's changed their fuse, do you re-insert it aligned a particular way? I've read it should only be a 45 degree turn clockwise after inserting the fuse, but it doesn't seem really "locked in" there. I don't dare twist or force it and risk breaking one of those flimsy tabs, but it seems like the slightest nudge makes it come loose. It's working fine, just makes me nervous that it's not really locked in there.

[Phlowen]

Replacing the fuse holder is a simple job. It may even have spade connectors on the inside which means you won't even need a soldering iron. You will have to make sure the amp is safe to work on though, a simple multi-meter to check there is no high voltage on it before you start.

If in any doubt though take it to a tech or any electronics service centre should be able to change the fuse holder.

I'm handy with soldering, but I've never been trained in checking for dangerous voltages (nor do I have the equipment) so I don't see myself opening it up without doing a lot of research first and getting the right tools. Unfortunately there are no techs or electronics service centres out here; I live way out in the sticks I'll have to weigh my options if I can't fix it from the outside I suppose.

Draining voltages from tube amps is pretty easy...if you're familiar enough with electronics to be handy with soldering, you should have no problem. Here's a video I found to be really helpful: https://www.youtube.com/watch?v=sw9KnSFy3Fs" onclick="window.open(this.href);return false;. I can vouch for it's truthfulness as I just did a bunch of work on my th30 using this method to drain the voltages and had 0 problem. Techs make everything sound scary and complicated to keep people paying them. High voltage is definitely not something to mess around with, and the warnings are valid...but the absolute fear surrounding it is unnecessary if you're intentional and careful.

[a.hun]

Draining voltages from tube amps is pretty easy...if you're familiar enough with electronics to be handy with soldering, you should have no problem. Here's a video I found to be really helpful: https://www.youtube.com/watch?v=sw9KnSFy3Fs" onclick="window.open(this.href);return false;. I can vouch for it's truthfulness as I just did a bunch of work on my th30 using this method to drain the voltages and had 0 problem. Techs make everything sound scary and complicated to keep people paying them. High voltage is definitely not something to mess around with, and the warnings are valid...but the absolute fear surrounding it is unnecessary if you're intentional and careful.

Sorry, but as I just pointed out HERE that is dangerous advice and doesn't apply to all amps by any means. I am very happy it did apply to your TH30!

Here is another thread on draining filter caps. Bonus really that you get to read it...
http://www.thegearpage.net/board/showth ... adid=74283" onclick="window.open(this.href);return false;


Andy.

[Phlowen]

Draining voltages from tube amps is pretty easy...if you're familiar enough with electronics to be handy with soldering, you should have no problem. Here's a video I found to be really helpful: https://www.youtube.com/watch?v=sw9KnSFy3Fs" onclick="window.open(this.href);return false;. I can vouch for it's truthfulness as I just did a bunch of work on my th30 using this method to drain the voltages and had 0 problem. Techs make everything sound scary and complicated to keep people paying them. High voltage is definitely not something to mess around with, and the warnings are valid...but the absolute fear surrounding it is unnecessary if you're intentional and careful.

Sorry, but as I just pointed out HERE that is dangerous advice and doesn't apply to all amps by any means. I am very happy it did apply to your TH30!
Here is another thread on draining filter caps. Bonus really that you get to read it...
http://www.thegearpage.net/board/showth ... adid=74283" onclick="window.open(this.href);return false;
Andy.

You're very right, one of the methods doesn't work on all amps, but the video I linked to shows two methods... two of the exact same methods as the given in thread you linked to...turn the amp off without turning bypass on (meaning without muting it)...which doesn't work on all amps...OR use a resistor probe and drain the caps manually...which definitely works on all amps.

The post to listen to in that thread is this: http://www.thegearpage.net/board/showpo ... ostcount=6" onclick="window.open(this.href);return false;