Qsc rmx1850hd doa

[guitardad]

QSC RMX 1850HD dead (breaker popped).

Found shorted 25A bridge. Checked all the Semis. All fine. No shorts. Popped in new bridge run up variac looking good to 90v then all of a sudden 18K mfd 50v cap explodes (just one). I'm assuming it was the main fault that took out the bridge which opened the breaker.

Contacted QSC for a schem, but just wondering if this is worth repairing in the first place. If that cap went is there an issue with the cap ratings. Seem low for 100+ rails. Before I order 8 filter caps and another bridge (that shorted out again) for a customer unit that does not want to spend more than $200 on this. 8 caps and bridge is about all I can do for that price.

Thx in advance

[Jazz P Bass]

The amp uses switching power rails.
Those caps don't see more than 44 volts.
So, yeah, they may be a tad low in there ratings.
If the bridge was spitting out Vac into that cap, that is what killed it.
The schematic can be found here: QSC RMX1850HD Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics

[guitardad]

The amp uses switching power rails.
Those caps don't see more than 44 volts.
So, yeah, they may be a tad low in there ratings.
If the bridge was spitting out Vac into that cap, that is what killed it.
The schematic can be found here: QSC RMX1850HD Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics

OK, so that means there is something else taking out the bridge. Kind of odd. I ordered the caps and bridge. Just have to wait and see how the next one goes.

The OEM bridge is nla and it was a MP254W. I am replacing it with a GBPC2502W.

Thx