I'm doing a repair on my Forte 4a, would appreciate any schematic that anyone out there can provide.
THanks but the Forte 4a is an amplifier, made by an offshoot of Threshold / Nelson Pass. Nothing to do with Klipsch.
Successful repair
I got a 47 ohm 1% 1 watt metal film resistor from Mouser and soldered it in to replace the one that burned up.
I had also found that the bolt on one of the DC rail filter caps to the aluminum ground bus plate was very loose - in fact it clearly had been arcing- so I cleaned up all the bolts and the grounding plate that goes between all the big filter caps - and replaced the bolt and lock washer that was all arc-pitted. I think when that bolt came loose a large current began flowing through the 47 ohm resistor and it burned up over time. So cleaning and tightening all the bolts to the capacitor terminals should keep this from happening again.
After replacing the 47 ohm resistor, that channel now works again as it should.
I'm just glad this fault didn't take out the unobtanium IGBT output devices.
I got a 47 ohm 1% 1 watt metal film resistor from Mouser and soldered it in to replace the one that burned up.
I had also found that the bolt on one of the DC rail filter caps to the aluminum ground bus plate was very loose - in fact it clearly had been arcing- so I cleaned up all the bolts and the grounding plate that goes between all the big filter caps - and replaced the bolt and lock washer that was all arc-pitted. I think when that bolt came loose a large current began flowing through the 47 ohm resistor and it burned up over time. So cleaning and tightening all the bolts to the capacitor terminals should keep this from happening again.
After replacing the 47 ohm resistor, that channel now works again as it should.
I'm just glad this fault didn't take out the unobtanium IGBT output devices.