Similar problem with my M-504
Hi Revenoor and Saabracer23, I have an issue with my M-504 as well and was wondering if either of you got yours fixed. I just got the service manual and plan to start looking into it. Mine lights up properly, but the servo never kicks in 5 seconds after power up. The meters are not pegged and it shows no other issues. A lightening strike was the culprit. It was not powered up at the time which is why I believe the grounding system was most likely damaged. The unit does not have a safety ground and therefore b/c it was not powered and none of the fuses blew, the damage must have occurred from that direction. I am also interested in getting broken ones for spare parts as we all know, many of the parts will be very hard to find if at all. Thanks.
Hi Revenoor and Saabracer23, I have an issue with my M-504 as well and was wondering if either of you got yours fixed. I just got the service manual and plan to start looking into it. Mine lights up properly, but the servo never kicks in 5 seconds after power up. The meters are not pegged and it shows no other issues. A lightening strike was the culprit. It was not powered up at the time which is why I believe the grounding system was most likely damaged. The unit does not have a safety ground and therefore b/c it was not powered and none of the fuses blew, the damage must have occurred from that direction. I am also interested in getting broken ones for spare parts as we all know, many of the parts will be very hard to find if at all. Thanks.
I have an M-504 also, which there's no signs of live when switched on; none of the LEDs lid up; the 2 Meters only jump up briefly then return to zero. I also noticed there's a black spot on the circuit board, which I suspect 1 or some of those transistors had burned out and left that black spot on the PCB. Does anybody have any ideas of what I should look for and how ...? Anybody has the schematics/service manual ?
Thanks in advance.
Larry D
Thanks in advance.
Larry D
I am currently troubleshooting a similar problem with a M-5099. The amp seems fine in that the protection circuit seems OK because the lights go from red to green and the relay clicks however, the meters peg on power up and return to zero about five second after powered down. I am studying the schematic but I must confess I'm not an experienced tech. I am considering that the ps caps may be the problem, any suggestions or helps would be appreciated and I will post on this thread any head way I make
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