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Mackie SRS1500 Class G repair help?
I will start of with an apology, being 70 years old & this is my first forum. Please feel free to ridicule, chuckle or shake heads when it comes to my electronic prowess.
I've had a lot of luck fixing my band's stuff for more than12 years - but repairing my SRS1500 this time has me frustrated to a full stop.
I am not sure of protocol to get help on this site but us retired old farts are happy to come up with some $$ to get it going again.- (or donate to the cause?)
I have all schematics if needed and have troubleshot using other posts on this website concerning the SRS1500. ( fix power supllies first)
Not sure how or if I am allowed to attach schematic PDF's. but issue 1 ?
BOTH Low voltage rails at test points +V2 & - V2 (ref 0V) now drop to 0V - BUT return to nominal when D16 , D11 are lifted (the diodes that tie the HI volt rails to LOW rails somehow on this Class G amp??)
HI volt rails test at V1+ & V1- are always +75v , -75v but something is dragging V2 rails down when tied to V1 rails circuit, it seems?
Q15 & Q27 get hot quickly & so I only test (powered on) for about 10 seconds.
I only have a multimeter now - but will have access to a shop this weekend with lots of testing stuff.
I have replaced the blown and/or tested all the "heat sunk" Mosfets drivers & such to the best of my limited knowledge, but now scratching my head & need real professional help. (boy do I !)
Any assistance or direction is greatly appreciated.
I've had a lot of luck fixing my band's stuff for more than12 years - but repairing my SRS1500 this time has me frustrated to a full stop.
I am not sure of protocol to get help on this site but us retired old farts are happy to come up with some $$ to get it going again.- (or donate to the cause?)
I have all schematics if needed and have troubleshot using other posts on this website concerning the SRS1500. ( fix power supllies first)
Not sure how or if I am allowed to attach schematic PDF's. but issue 1 ?
BOTH Low voltage rails at test points +V2 & - V2 (ref 0V) now drop to 0V - BUT return to nominal when D16 , D11 are lifted (the diodes that tie the HI volt rails to LOW rails somehow on this Class G amp??)
HI volt rails test at V1+ & V1- are always +75v , -75v but something is dragging V2 rails down when tied to V1 rails circuit, it seems?
Q15 & Q27 get hot quickly & so I only test (powered on) for about 10 seconds.
I only have a multimeter now - but will have access to a shop this weekend with lots of testing stuff.
I have replaced the blown and/or tested all the "heat sunk" Mosfets drivers & such to the best of my limited knowledge, but now scratching my head & need real professional help. (boy do I !)
Any assistance or direction is greatly appreciated.
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