KEF Cube 12 Active Subwoofer Power Supply Faulty

[erkanderya]

Hi friends.
I repair electronic boards, KEF Cube 12 Active Subwoofer Power Supply Defective on my desk right now..
Has anyone encountered this kind of failure?
1.Capacitors on the board have changed.
2.U503 (203D6 IC) Changed
3.U800 (RHG 1072a) Changed
4.Bridge diode replaced
5.there is no corrupt element visible from the outside

Thank you, friends

 

[Nigel Goodwin]

Have you done any fault finding?, or just randomly replaced components? - and do you have a schematic?.

 

[erkanderya]

Have you done any fault finding?, or just randomly replaced components? - and do you have a schematic?.

there is not have any diagram, the U800 was defective, I just replaced the other parts, they were not defective (capacitors and bridge diode)

 

[Nigel Goodwin]

If there's no schematic, then it's probably a good idea to draw one out - U800 failing is probably a symptom rather than a cause, you need to find the actual reason for it's failure. Then there's the likelihood of other components being damaged by the failure, it's essential to find and replace every failed or damaged component, otherwise it's likely that components will fail again the instant you power it up.