Behringer GMX1200H guitar amp, 2011 (?)

Stock fault ? Phones o/p but no sp o/p. Both pcb traces to the main bridge rects fried.

2xLM3886 seem ok cold DVM "test". Both main caps good ESR and capacity, diodes test ok. Both main caps bowed ends and one with brownish dried "wax" at the cross, presumably electrolyte but no hole seen. All the caps on the PA are Xunda, don't remember seeing that name before, suspect? presumably China. Main caps are radial Xunda RK series, 3300uF,50V 105 deg C, the supposed glue to the pcb has (heat?)failed and they can flop around on axial-type gauge of terminals, not snap-in.
Reply to
N_Cook
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Sounds like the main caps have blown/shorted

Reply to
stevehenderson388

Yes, in my opinion too small caps squashed into a small place on a heated part of the board, considering the amount of space available in this valve amp size, full width head .

18mm diam, x35mm, 105 deg C, is suspiciously small for 3300uF,50V. Fixed 2 proper size 80V 3300uF to the cooler metalwork and so far running fine. Wire replacements to the burnt traces, leaving unburnt and unlifted parts of the traces as "fuses"
Reply to
N_Cook

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