paul_5 Posted February 28, 2013 Share Posted February 28, 2013 Anybody else had this problem with their 220? The power light doesn't come on, but the Power amp clip light is on all the time and nay sound comes out. I've tried plugging the bass into the FX return and Power amp in, but still no sound. Any ideas? Quote Link to comment Share on other sites More sharing options...
MarkBassChat Posted February 28, 2013 Share Posted February 28, 2013 (edited) I don't know why you have no sound with the power amp but the power amp clip light suggest that one low voltage rails (either +15, or -15V) is missing. Can you measure the voltage on Zener diodes (after large, white resistors) in the power supply? I'm only guessing but I would start with this measurement. Mark Edited February 28, 2013 by MarkBassChat Quote Link to comment Share on other sites More sharing options...
BassBod Posted February 28, 2013 Share Posted February 28, 2013 No idea...get it to a good tech - mine have commented on how well they are put together (meaning they are very fixable!) I might even have a circuit plan somewhere - PM me if you think it would help? Quote Link to comment Share on other sites More sharing options...
icastle Posted February 28, 2013 Share Posted February 28, 2013 There is a fault similar to yours described [url="http://music-electronics-forum.com/t30669/"]here[/url]. Unfortunately, the diagnosis (and subsequent solution) is going to be a bit hit and miss unless you have the appropriate equipment. Quote Link to comment Share on other sites More sharing options...
icastle Posted February 28, 2013 Share Posted February 28, 2013 [quote name='BassBod' timestamp='1362090104' post='1995773'] No idea...get it to a good tech - mine have commented on how well they are put together (meaning they are very fixable!) [/quote] They're dead right - nearly all of the components are easily available 'off the shelf' stuff that most decent amp techs will have to hand. Quote Link to comment Share on other sites More sharing options...
paul_5 Posted March 1, 2013 Author Share Posted March 1, 2013 Got replacement parts for most of the pre section in me 'bits box'... I'll make the coffee and get me meter out Quote Link to comment Share on other sites More sharing options...
paul_5 Posted March 1, 2013 Author Share Posted March 1, 2013 spent an hour tonight checking components and nothing seems broken - the game is afoot! Quote Link to comment Share on other sites More sharing options...
icastle Posted March 1, 2013 Share Posted March 1, 2013 [quote name='paul_5' timestamp='1362178080' post='1996959'] spent an hour tonight checking components and nothing seems broken - the game is afoot! [/quote] Quote Link to comment Share on other sites More sharing options...
paul_5 Posted March 1, 2013 Author Share Posted March 1, 2013 will check the voltage rails tomorrow. CBA right now. Quote Link to comment Share on other sites More sharing options...
paul_5 Posted March 3, 2013 Author Share Posted March 3, 2013 Well, thanks for the replies and schematics chaps, you're an awful lot faster than SWR themselves who haven't responded to my email from the end of February yet. Is this normal? Quote Link to comment Share on other sites More sharing options...
BassBod Posted March 6, 2013 Share Posted March 6, 2013 SWR used to be pretty good at helping (even when Fender owned) but there are interweb rumours that they might not be long for this (corporate) world...see talk bass. Quote Link to comment Share on other sites More sharing options...
paul_5 Posted March 16, 2013 Author Share Posted March 16, 2013 Had a mail back from 'Bob' complete with schematics for the pre and power stages. Last night I replaced two fritzed diodes and it's 'business as usual'. Happy days. Quote Link to comment Share on other sites More sharing options...
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