[quote name='Quoth'd' post='1130930' date='Feb 17 2011, 01:03 PM']I have a Hartke 3500 (with corners and rack ears) . . . Now after doing a good turn for (now ex-guitarist) and offering to fix some of his PA cabs for him I made the mistake of using my beloved amp as to test for faults.
After a quick turn of very quiet sound level quickly getting fainter - the amp went pop, wiz, bang and then silent [the day of a gig too] So after disassembling the speaker I quickly found out that the crossover had gone and went short as it warmed up (cause of blown amp established).
That left me with my amp to fix. I pulled it apart & did all the usual checks then found that the output transistors had blown. So after a quick hunt round, I found a set of compatible replacements for the 4x pairs of output transistors which I fitted and checked again.
Good signal with tone source when quiet but as I turned the gain up - a distortion creped in (on the scope it looked like a saw wave on the negative signwave - top half fine / bottom half jagged). The louder the output gain the more distorted the output.
Now my dilemma is this - I have replaced amp with a lovely Gallien Krueger backline which I am loving & looking forward to cranking when am back in a band again. I have a semi-working Hartke 3500 which I don't need so am wondering if it would be better to call Samson & order the replacement output (loaded) PCB then sell it as refurbished [u]or[/u] to sell it as non-working [u]or[/u] to break it and sell individual bits (case / front panel / transformer / pre-amp-board / send-return board / output board / heatsink etc).
Any advice gratefully received as am loathed to flebay it and walk away with a miserable £20.
Thanks
Si[/quote]
I'd fix it, mine was bought faulty (valve preamp section not working). Turns out a resistor had burned out on the board. Replaced all the nearby caps (one of which might have caused the failure) and the burned resistor. Broke the stupid bit which goes to the compressor control on the front panel and had to repair that by running some wires instead of relying on PCB tracks. That was 2 1/2 years ago now and it's been working great ever since.