My Orange amp recently stopped working, as in no sound

If everything lights up and responds to button pushes like normal, and you've done a hard reset as described in the manual, check to see if you have sound out of the headphone jack. It's most likely not a user serviceable problem and will need to go to the shop, but it will probably be the output amp rather than the main board.

brown outs are usually power supply issues I don'y have schematic but i would check tube in ps in the old days we would look for leaking capacitors or spray suspect resistor or caps with a spray chill in a can (and be very careful not to hit tubes) defective part will work. Since this is done when amp is on, one need to remember that fatal voltages and currents are exposed. This is not for causal or inexperienced persons.
extreme caution required. (I am providing info but am not responsible for any one doing it)

i'm having the same problem ... :/ anyone please! heelp!

actually there are a few ways of doing this that require no disassembly ( and i better get a good rateing for revealing these secrets haha ) check it out. take a Q-Tip and break off one of the fluffy heads. Apply some super glue to the end you broke off and shove that into the 1/4"jack and essentially glue it to the qtr inch tip. let this sit for a second and pull. should come right out IF NOT you can also try to find a screw ( usually a wood screw ) and you can thread that into the hole of the tip of the connector. if this doesnt get it out post back so i'll know and i'll walk you through how to remove the chassis and pcb's safetly. good luck!

I am contacting orange to see if there is some way to help you.

I have done a lot of searches for any information on this unit and cannot even find a user manual to get information to help you. A 100 watt convertor sounds like it is too large and may not be the right one. A light coming on for a second and going off could be just the discharging of the power supply capacitors. I am sure others are searching for information and this is a poor company to not have even a manual available online. Do remember this only has a 6.5 inch speaker so don't expect it to be as loud as a larger guitar amp. If you can get photos of the connectors I might be able to help you, but with no manuals or other info the experts here will not be able to find any information. These amps are only $60 new. If a fuse went, there is another failure causing it. I will try a few more times to find at least a manual.

UNPLUG THE AMP
First you need to check any visible fuses either in the plug or on the back of the amp.
If you have an electrical testing screwdriver or meter you can test the fuse. If this sounds like gobbledegook (daft talk) then stop and take it to the dealer where you bought it.
If you can remove the fuse or fuses then replace them if it is obvious they have blown - dark and kinda burnt looking.
If replacing the fuses doesn't fix it - STOP.
Valve amps are serious bits of electrical hardware - they are not for home repairs - take it to a GOOD dealer / repair shop that deals with valve amp - nowhere else should play with it. When they have it sorted you can have the valves re-biased/changed to adjust the amp for the sound you want - yes the valves can change it.
Hope this helps - don't mess with it - even when turned OFF valve amps can give you a shock!!
Keep on Rockin'

Here is a link, unfortunately it requires a different viewer than Adobe but you can find the special viewer although the viewer may not be a free program.

http://elektrotanya.com/orange_ad-30r_sch.djvu/download.html

Apparently you have tested the tubes on a tester and usually there is a pilot light that would not be lit if fuse was blown.

Common problems are bad jacks and switch contacts on power amp INPUT or INSERT jacks. Also circuit board cracks and bad solder joints are fairly common, especially where volume controls attach to the circuit boards.

More expensive things are things like fried speaker if volume was played too loud. An ohmmeter test of the speaker would tell if the voice coil has blown.

The pilot light means NOTHING other than the switch is on and unit is getting power from a receptacle.

There is an electronic failure that requires servicing and until unit is opened and analyzed we can''t help you further. Take it to a shop or a person experienced in electronic repair.