Be careful with your soldering as these are multilayer boards (5 layers I think). You do not want to pull out a via and lose connectivity to an inner layer circuit.
If your bias pots go open after a failure, 13 ohms seems about right for a fixed resistor to set the proper bias of 80mv across R2 or R106 (Ch1/Ch2).
If your bias pots go open after a failure, 13 ohms seems about right for a fixed resistor to set the proper bias of 80mv across R2 or R106 (Ch1/Ch2).
I just repaired one as well. the 15V zener diode went bad causing the amp to lock up and it took out the triac crowbar output the Fet, all the output transistors, the emitter resistors, base resistors, and just about every other component in that section. But, With the help of the QSC service manual, i was able to get it back up and running pretty easily.
The current fold back test is a bugger however. shorting the output of the amp to check for current foldback then recovery at full power into a 2 ohm load requires a BIG resistor bank!
Zc
The current fold back test is a bugger however. shorting the output of the amp to check for current foldback then recovery at full power into a 2 ohm load requires a BIG resistor bank!
Zc
ep2500
There are four 15V zeners (two for each channel) located on the Ch2 board. My zeners were OK but both 4580s were blown sinking the + & - 15 supplies. Thats because they're DC coupled to the output stage.
I'm surprised Behringer didn't put some glue on those pots. Those bass notes at some high energy concerts are sure to make them "creep".
And the fan needs to be turned around so it pulls cool air in from the front (the filter is on the inside of the front panel). With the fan sucking from the back, it will fill up with dust and you wouldn't know that the back of the filter is clogged.
There are four 15V zeners (two for each channel) located on the Ch2 board. My zeners were OK but both 4580s were blown sinking the + & - 15 supplies. Thats because they're DC coupled to the output stage.
I'm surprised Behringer didn't put some glue on those pots. Those bass notes at some high energy concerts are sure to make them "creep".
And the fan needs to be turned around so it pulls cool air in from the front (the filter is on the inside of the front panel). With the fan sucking from the back, it will fill up with dust and you wouldn't know that the back of the filter is clogged.
Have a friend with an EP2500 but channel 1 does not work. Any idea where we can purchase repair parts? You can email me direct at cncaton2002@gmail.com.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.