Good Morning all! Apologies that my first post is an SOS, I'm trying to help our bassist out with an amp issue. I've included a brief description of the issue and the troubleshooting that I've tried already etc, would appreciate any help immensely! Issue: Amp will periodically cut out, producing no sound whatsoever. Used to be sporadic and short, now struggling to get it to consistently produce sound for more than 10 minutes. Setup: Fender Precision Bass > Sansamp Basss Driver Deluxe > Hartke LH500 > Hydrive 4x10 cab all in line, not FX looped. Troubleshooting thus far: 1 - Replaced leads. No change. 2 - Took Sansamp out of chain. No change. 3 - Head into different cab. No change 4 - Effect Send into PA - signal present. 5 - Amp DI into PA - signal present. 6 - Bass straight into Effect Return - No change Conclusions thus far: From what I've seen I think it is an issue with the power amp stage of the head, as the DI out and Effect Send are both still generating signal, indicating to me that the Preamp is still working. Other info: Our bassist bought the amp in April 2011 and so it is out of store warranty (12 months - Dawsons). The store are also saying that Korg now owns Hartke and doesn't offer an extended warranty. We're gutted because the LH500/Hybrid combo sound is totally integral to his sound and ours as a band, but at the moment he's feeling jaded about Harkte as a brand, which I think is misguided! Help: 1 - Has anyone had experience of the same issue with this amp and how (if!)you managed to resolve it. 2 - Does anyone here work for or has experience dealing with Hartke/Korg (especially in the UK) and could advise on the warranty/repair policy. I heard Hartke in the US are insanely helpful, to the point of the company founder getting stuck in with people's issues! I am sure there must be some assistance available in the UK, I think the store are either ill informed or they don't care! 3 - Has my troubleshooting missed anything (more than likely!)? 4 - If there is no help available from Hartke/Korg after 12 months, does anyone know a good/reasonably priced bass tech in the South of England who would be able to fix this for us. Thanks so much in advance of your help!