AS90 Posted January 18, 2010 Share Posted January 18, 2010 I have a Harley Benton GA5H which has started 'fading out' after a few minutes, Any ideas? Link to comment Share on other sites More sharing options...
Eracer_Team Posted January 18, 2010 Share Posted January 18, 2010 can't remember if the GA5 had the same inline fuses as the Valve Jr. like this picture the brass connectors inside need to be scraped Link to comment Share on other sites More sharing options...
AS90 Posted January 18, 2010 Author Share Posted January 18, 2010 Would that cause it to play normally for 30 minutes then fade away to nothing only to work normally again after a while? Link to comment Share on other sites More sharing options...
TWANG Posted January 18, 2010 Share Posted January 18, 2010 I don't think so. that is, the word fade kinda throws me.. how fast? it could do that.. but the fade would be rather quick. Link to comment Share on other sites More sharing options...
shartom Posted January 22, 2010 Share Posted January 22, 2010 When you say fade out, does the amp go dead...no pilot light? Does the sound distort at all? I'm not familiar with your amp. I've serviced a lot of amps over the years. Let me know exactly what is happening and I'll try and help you. Link to comment Share on other sites More sharing options...
m-theory Posted January 22, 2010 Share Posted January 22, 2010 replace the output tube Link to comment Share on other sites More sharing options...
MikeRom Posted January 23, 2010 Share Posted January 23, 2010 Tough one to guess at. Sounds like a component is failing after it warms up and it could be almost anything, capacitor, resistor, diode, tube. Before spending money on shot gunning a solution I would take it to a tech unless you are good at trouble shooting electronics yourself. Link to comment Share on other sites More sharing options...
AS90 Posted February 4, 2010 Author Share Posted February 4, 2010 Sorry I forgot I posted this question! So, the amp has worked fine now for a week or so, but it happened again today. The sound just fades to nothing in about 5 seconds, there is still power to it, just no sound. After 5 minutes it was working again? I dont want to take it to a tech as it was only £62 new and is supposed to be a modding platform! (still stock after 3 years! ) Link to comment Share on other sites More sharing options...
atfab Posted February 4, 2010 Share Posted February 4, 2010 Try this forum/thread Link Link to comment Share on other sites More sharing options...
RSDx Posted February 4, 2010 Share Posted February 4, 2010 The sound just fades to nothing in about 5 seconds' date=' [b']there is still power to it, just no sound[/b]. After 5 minutes it was working again? Are the tubes still lit up when the sound fades out ? Link to comment Share on other sites More sharing options...
AS90 Posted February 5, 2010 Author Share Posted February 5, 2010 Are the tubes still lit up when the sound fades out ? Ok, I just sat here playing for an hour watching the tube and waiting for it to die! Finally went, and yes the tube stopped glowing as the sound died. The sound came back briefly and so did the glow before going again. Link to comment Share on other sites More sharing options...
AS90 Posted February 7, 2010 Author Share Posted February 7, 2010 So Im thinking new tube? Link to comment Share on other sites More sharing options...
cGil Posted February 8, 2010 Share Posted February 8, 2010 The glow in your tubes is due to your filament heater getting enough juice to operate. As voltage to the filament drops, so will the glow, and because the tube can't operate without it, your output volume drops off as this happens. Simply clean the pressure contacts inside the heater winding's fuse holder. Buff 'em with steel wool to get any remaining factory varnish and oxidation off of 'em. If they aren't flat, file 'em. You need as much surface area in contact with the fuse as is possible. And use some ProGold metal treatment or something if you've got it to keep the contact pads clean and conducting properly. End of problem. Gil... Link to comment Share on other sites More sharing options...
AS90 Posted February 8, 2010 Author Share Posted February 8, 2010 The glow in your tubes is due to your filament heater getting enough juice to operate. As voltage to the filament drops' date=' so will the glow, and because the tube can't operate without it, your output volume drops off as this happens. Simply clean the pressure contacts inside the heater winding's fuse holder. Buff 'em with steel wool to get any remaining factory varnish and oxidation off of 'em. If they aren't flat, file 'em. You need as much surface area in contact with the fuse as is possible. And use some ProGold metal treatment or something if you've got it to keep the contact pads clean and conducting properly. End of problem. Gil...[/quote'] I'll give it a go, cheers. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.