I have a Samson L612M powered monitor to repair -- haven't been able to find the right schematic -- almost given up. I have schematics for the L1212 and the DB500A -- both of these have elements that match up to the L612M, but neither is the right one. The power amp board is silk-screened "DB300A power amp bd" so I assume it shares that board with the DB300A -- BUT, I can only find the DB500A schematic, not the 300. The L612M has a TDA7294 monolithic 100W IC power amplifier -- this is in none of the schematics. Thanks for any ideas about where to find the schematic.
Also must say that this unit is designed in a very screwy way and is not repair friendly at all, woof.
Also must say that this unit is designed in a very screwy way and is not repair friendly at all, woof.
Samson and other cheap pro equipment were never meant to be repaired and that's why there's no info available. I have a Samson mixer here that the only thing wrong with it is a broken XLR connector. I've ordered every type of XLR connector I can find but nothing fits this mixer. Most XLR connectors are built to a standard but Samson seems to have their own standard. Samson is impossible to get a hold of either phone or email, they probably won't have the part anyway.
Craig
Craig
The TDA7294 is probably bridged since it is a 250+50W speaker.
Check bridge schematics for help. The must be another IC for the HF section also.
As far as XLR concerns. XLR has standard dimensions so a standard cable plugs in.
If You can't find one with the same height, use wires, bend pins ...
Instead of PCB fixing, enlarge the hole & screw it over the panel.
Check bridge schematics for help. The must be another IC for the HF section also.
As far as XLR concerns. XLR has standard dimensions so a standard cable plugs in.
If You can't find one with the same height, use wires, bend pins ...
Instead of PCB fixing, enlarge the hole & screw it over the panel.
All TDA7294 amplifiers have a switching circuit close to the typical one. Check supply voltages, IC modes. Also check the small OPamp in the signal circuit.
L612M Two-way bi-amped active stage monitor 300 watts
EEVblog #1322 - JBL LSR308 Studio Monitor Speaker REPAIR - YouTube
L612M Two-way bi-amped active stage monitor 300 watts
EEVblog #1322 - JBL LSR308 Studio Monitor Speaker REPAIR - YouTube
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Thanks for responses -- the TDA chip isn't suspected yet -- I need the schematic because I've got a thermal fault signal going active erroneously -- with the schematic I would be able to trace signals -- I figure since these two other schematics are out there, someone might have the one I'm looking for but I'm not holding my breath
Maybe I need to bring a fruit basket into a Samson authorized service center, those poor, poor people that have to work on these POS's.
Maybe I need to bring a fruit basket into a Samson authorized service center, those poor, poor people that have to work on these POS's.
The Service Centers don't work on them either. Had a couple of Numark power amplifiers in for service a few years ago and the ONLY thing wrong was toasted resistors in the output Zobel networks. I called Numark to get schematics or the value of the resistor, they had no info. Then they gave me a couple of telephone numbers to their Service Centers. I called them and was told they don't work on them and just send them back to Numark as they had no info either. So sad these days.
Craig
Craig