el84 1 channel stopped working help

[eddiedavies]

el84 1 channel stopped working help

Can anyone help me please, I have a problem with my el84. its been a cracking little amp I have had it for about 4 months, the warrantee on this amp wasn't worth having it will have to go back to china to be fixed at all my cost and I will also be without it for around 2 months, that's if I ever see it again. All the valves work fine its just that the 1 right channel has totally stopped working I have swapped the tubes and speakers etc but nothing works the channel is dead, The units rear body also doesn't get hot like it used to when it was working fine. Im no electronics expert and have little knowledge of circuits, but I have comon sense and I am a dab hand with a soldering iron and im sure with some guidance I could fix it but I don't know where to start can anyone help, the actual amp seems pretty basic but as I said I dont know where to start, It would be greatly appreciated. I love this little amp and there is nobody local who can help, I could send detailed photos of individual parts and anything else thats needed. Hope theres someone who can help.

 

[zanash]

check the fuses .....see if there are any internal ones

so you have tried swapping the signal tubes as well as the power tubes ?

check your speaker connections too ...remember most valve amps do not like to be run without the speakers ....

failing that swap the interconnections over as the fault may lie up stream !

 

[themadhippy]

once youve checked for obvious things its time to get the test gear out,a circuit diagram is also pretty helpfull, i'd first test for a signal at the volume control,then work folward or back from this point.

couple of things to watch out for
1) valves like high voltages,if you need to work live keep one hand in your pocket
2)dont power the amp up without a load attached,a 10 ohm 7 watt resistor is a safer (and quieter )option to speakers

 

[dean.l]

firstly does it smell burnt? did it smoke?


I would like to say it was just an output or an input wire come loose, has the amp been moved about a lot recently ?

but i'd bet it isn't as simple as that
start with fuses etc as above then check the mains transformer for a bacon type smell and wax drips around the base. coupling caps output transformer and just burnt stuff in general.

but really if you know nothing at all about valve amps then I would just open it up (after leaving it plugged in but not turned on at the wall for a day or so) then check for loose wires and burnt components if there are burnt resistors try the coupling caps (unsolder one end and check to see if they have a short with a multimeter)
if they do change them and the resistors for the cheapest ones you can find. if it then works go treat yourself to some decent ones for both sides.

if any of the above sounds daunting then I would take the amp as it is to a tv repair shop (along with a wiring diagram) and they should fix it fairly cheaply.

ps all of the above is only my opinion and is not to be taken as fact
I don't know much about valve amps, although I have built a few I am not an expert.