0175westwood29 Posted September 29, 2011 Share Posted September 29, 2011 hi guys im really hoping some of you can help as im freaking out a bit! was at practice with my band, and as we have a gig on saturday(oct 1st) we were running our whole set list about 2 and a half hours of stuff! well were were going along just fine did our cover of teenage kicks amp had been sounding awesome! had some fuzz and delay going on. finished that song and the guitarist broke his e string, as he was trying to find a new one i was noodling around and talking to our drummer. then he couldnt find one so we decided to play on without him, then i heard a slight click, not that loud at all just vagely noticed then no noise! nothing my amp was on and nothing had changed from a second ago when it sounded awesome! wasnt hot, dnt think i was pushing it etc, sounded wicked in the last song id played! any ideas ive got a gig sat and really wanted to play this amp as i finally had my rig sounding how i wanted! please help! andy Quote Link to comment Share on other sites More sharing options...
icastle Posted September 29, 2011 Share Posted September 29, 2011 This unit has a whole pile of protection circuitry inside it. The 'click' was probably the output relay switching off. First thing that springs to mind is the cable betwen the amp and the speaker(s) - if it has a short circuit then the output relay will cut out straight away. Try changing the speaker cable for a known working one before paying out for repairs... HTH Quote Link to comment Share on other sites More sharing options...
JTUK Posted September 30, 2011 Share Posted September 30, 2011 As above in the first instance... then check any internal line fuses... The good thing is that there was nothing apparently dramatic in the shutdown..no smoke, sparks or noise..so the shutdown seems orderly...???? Not sure if these things trip out and reset, but swap out cabling/leads that could make the amp go into shutown mode,. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted September 30, 2011 Share Posted September 30, 2011 If it's not just a fuse or bad cable there's nothing you can do to fix it anyway. Check those and if no luck get it into the shop. Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted September 30, 2011 Author Share Posted September 30, 2011 thanks for the replies guys! im trying not to freakout! changed my guitar lead, the speakon to the cab, changed the input im usingfor the speakon and still no joy! im not sure but the light that flashes before the amps ready to use looked like it was flashing a bit faster but it still goes thru the whole diagnostic thing and allows me to turn it on? does that not check for fuses? etc? anyone know what type of fuse it could be? andy Quote Link to comment Share on other sites More sharing options...
JTUK Posted September 30, 2011 Share Posted September 30, 2011 no... internal fuses will be rated as per..and you need to open it and have a look. My amp has these line fuses per channel on the outside at the back...others might not. But...... fuses go for a reason so at this point it would be to a tech asap. Quote Link to comment Share on other sites More sharing options...
icastle Posted September 30, 2011 Share Posted September 30, 2011 Pinched from Aguilar: [center][b][size="4"]Aguilar DB750 Hybrid Head [/size][/b][/center][center][b][size="4"]Diagnostic and Protection [/size][/b][/center][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]The DB750 is equipped with a self-diagnostic and status/protection circuit. Upon power-up the unit’s blue status LED will blink for approximately 45 seconds. During this time several circuit parameters are verified, or allowed to become self calibrated. [/size][/font][/size][/font][/left][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]1. The high B+ voltage to the preamp tubes is slowly ramped up, allowing the tube heaters to warm up before full current us drawn by the valves. [/size][/font][/size][/font][/left][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]2. DC offset at the amp’s output is monitored. Only if none is present (normal condition), will the unit proceed with the self-check protocol. [/size][/font][/size][/font][/left][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]3. Temperature on the MOSFET heat sink is checked, and again only if normal temperature is detected, will the status check to continue. [/size][/font][/size][/font][/left][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]4. If all the voltages, offsets, and temperature are in accordance with factory specifications, then the amp’s input, and output relays will be energized. This will then cause the operate LED to illuminate and status LED to stop blinking, and the amp is now ready for normal operation. [/size][/font][/size][/font][/left][left][font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]5. Continues monitoring of the above parameters, protect both the DB 750 and speakers connected to the amp, in the event of unit, of user error. This will be indicated by the status LED’s blinking. [/size][/font][/size][/font][/left] [font="Times New Roman,Times New Roman"][size="3"][font="Times New Roman,Times New Roman"][size="3"]6. If the status LED continues blinking, or starts blinking during amplifier use, this indicates a system fault. The amplifier requires servicing in order for normal operation to resume. [/size][/font][/size][/font] Quote Link to comment Share on other sites More sharing options...
charic Posted September 30, 2011 Share Posted September 30, 2011 Do tubes make a noise when they go? Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted September 30, 2011 Author Share Posted September 30, 2011 See this is where its freaking me a bit, i went home and found that in my catalogue, but it goes thru the diagnostic and allows me to take it of stanby and the led never flashed? Just no sound coming out i know the leads are good, the tubes would come up in the diag? Mh bass and all those cables are good? My cab seems ok!? No farting etc before hand, and i played for about 30 mins after to make sure with our drummers trace elliot v4 head? Any more ideas? The output fuse is there a reset for it on the back? Didnt look last night was panicking! Andy Quote Link to comment Share on other sites More sharing options...
charic Posted September 30, 2011 Share Posted September 30, 2011 Have you checked a signal is actually reaching the amp? Have you plugged into anything else with you bass to check that? Quote Link to comment Share on other sites More sharing options...
charic Posted September 30, 2011 Share Posted September 30, 2011 I'd also see if there was anything coming out of the XLR out just to cover all ports of call Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted September 30, 2011 Author Share Posted September 30, 2011 [quote name='charic' timestamp='1317392756' post='1390293']Have you checked a signal is actually reaching the amp? Have you plugged into anything else with you bass to check that?[/quote][quote name='charic' timestamp='1317392978' post='1390297']I'd also see if there was anything coming out of the XLR out just to cover all ports of call[/quote] are pa isnt at our reheasal due to the gig so i couldnt try that, and yeh as i said above you might have missed it tho? i plugged into a trace v4 for the last half hour of our practice and also the guitarists marhsall mode 4 and all worked fine. so im kinda stuck! trying to get hold of the place i got it to take it in tomoz morning! andy Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted September 30, 2011 Share Posted September 30, 2011 Take the guitar lead, amp/speaker cable and mains cable you were using with the DB750 and try those with a different amp [b]and[/b] different cab (you'd be amazed how many people say they have done that and it turns out they have just taken the guitar lead... or tried neither), if they work try replacing your DB750 into that signal chain; that at least rules out any external factor and indicates it is defo your amp! Honestly there is nothing more embarrassing than when a repair guy powers it up and it works fine because it was something else in the set-up. Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted September 30, 2011 Author Share Posted September 30, 2011 [quote name='warwickhunt' timestamp='1317398616' post='1390408'] Take the guitar lead, amp/speaker cable and mains cable you were using with the DB750 and try those with a different amp [b]and[/b] different cab (you'd be amazed how many people say they have done that and it turns out they have just taken the guitar lead... or tried neither), if they work try replacing your DB750 into that signal chain; that at least rules out any external factor and indicates it is defo your amp! Honestly there is nothing more embarrassing than when a repair guy powers it up and it works fine because it was something else in the set-up. [/quote] hi i think some of you guys must be misunderstanding my first post. ive tested my cab using another amp my drummer v4 and it sounds like its ok nothing wrong there, in doing that i used the same signal chain as i had with my aggie and to run the new head i used the power lead from my aggie. the speakon cable was proved as it was running our monitiors for our vocals so thats good. and just incase i changed the batteries on my bass and also tried a guitar thru my amp and still nadda! also i just remembered i lleft the amp off for about 20mins before trying it again and still the same thing! i was just really confused! everything said it should work! the diag went all the way thru and doesnt flash at all! didnt even flash when it happened! andy Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted September 30, 2011 Share Posted September 30, 2011 [quote name='0175westwood29' timestamp='1317402973' post='1390477'] hi i think some of you guys must be misunderstanding my first post. ive tested my cab using another amp my drummer v4 and it sounds like its ok nothing wrong there, in doing that i used the same signal chain as i had with my aggie and to run the new head i used the power lead from my aggie. the speakon cable was proved as it was running our monitiors for our vocals so thats good. and just incase i changed the batteries on my bass and also tried a guitar thru my amp and still nadda! also i just remembered i lleft the amp off for about 20mins before trying it again and still the same thing! i was just really confused! everything said it should work! the diag went all the way thru and doesnt flash at all! didnt even flash when it happened! andy[/quote] Didn't intend to cast aspersions on your ability to eliminate the obvious Andy. Sometimes it's worth stating the obvious to posters as some may not have the experience (as you have) to try and eliminate the most obvious causes! Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted September 30, 2011 Author Share Posted September 30, 2011 [quote name='warwickhunt' timestamp='1317403711' post='1390485'] Didn't intend to cast aspersions on your ability to eliminate the obvious Andy. Sometimes it's worth stating the obvious to posters as some may not have the experience (as you have) to try and eliminate the most obvious causes! [/quote] oh believe took about three people taking to me to make me check everything! was freaking out that amp is like my baby! ive got hold of where i bought so gonna try and take it up there tomoz! fingers crossed he can fix it then and there! just thinking is there any way to damage the tubes by putting to much gain/distortion into the front of the amp? just thinking of what i was doing when it stopped? andy Quote Link to comment Share on other sites More sharing options...
citymariner Posted September 30, 2011 Share Posted September 30, 2011 Mate, I feel your pain! I was at a gig and it happened to me during soundcheck - exactly what you have described but with my Ashdown Klystron head. I actually felt my insides turn to liquid. I couldn't think straight checking stuff. I checked everything I could whilst there and ended up having to get another rig form home. It wasn't till the next morning could i logically check stuff. Ashdown ended up shipping me a new head and collecting my other one. I hope you get stuff sorted, like others have said there is a reason it has done this and a short term fix of replacing a fuse or resetting something my just whitewash over the problem. Best get a tech to it. Good luck, Josh Quote Link to comment Share on other sites More sharing options...
charic Posted September 30, 2011 Share Posted September 30, 2011 You have checked the master volume right? let us know how you get on with the tech Quote Link to comment Share on other sites More sharing options...
PauBass Posted September 30, 2011 Share Posted September 30, 2011 My DB751 stopped working at band practice about 5 months ago, the self diagnostic did his job and everything seemed to be OK but still no sound so I open it up and it was just one of the Preamp Valves that had gone bad...I replaced it and that was it. Hope this helps mate. Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted October 1, 2011 Author Share Posted October 1, 2011 [quote name='PauBass' timestamp='1317422658' post='1390721'] My DB751 stopped working at band practice about 5 months ago, the self diagnostic did his job and everything seemed to be OK but still no sound so I open it up and it was just one of the Preamp Valves that had gone bad...I replaced it and that was it. Hope this helps mate. [/quote] now that sounds exactly like what happened! tech this morning so fingers crossed! andy Quote Link to comment Share on other sites More sharing options...
0175westwood29 Posted October 1, 2011 Author Share Posted October 1, 2011 [quote name='charic' timestamp='1317418010' post='1390672'] You have checked the master volume right? let us know how you get on with the tech [/quote] yeh man indeed i did. took it to the tech this morn! he said it sounds like a tube could have gone? but on the good side he did lend me a db750 so i still had an amp for the gig tonight! andy Quote Link to comment Share on other sites More sharing options...
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