Help identity blown part in Alesis Mixer PS

[R_J]

Re: Help identity blown part in Alesis Mixer PS

I suspect the MK-328 can't measure it properly. I will ask again, Is the power supply working or not?

[Carm99]

Re: Help identity blown part in Alesis Mixer PS

Ill have to replace the 2200 cap and the small ceramic one then see if it works.
Ill let you know after that, what happened hopefully it wont blow the small cap again. again.
Thanks so far anyway.

[R_J]

Re: Help identity blown part in Alesis Mixer PS

That small cap likely went on its own. and if you want to try the supply you can try it without that cap. installed for now. Like I said I doubt that 2200µf cap is bad, if it was it would have either leaked or bulged.
The most voltage across the small .1µf is 25 volts, It is not uncommon for them to fail shorted

[R_J]

Re: Help identity blown part in Alesis Mixer PS

The 2200 big cap on the board is testing 0.00Ω esr.

Did you happpen to check the capacity of the cap also? or just the esr? That 0.00Ω esr seemed a bit odd to me. I guess the cap could be completely open and not measuring anything

[Carm99]

Re: Help identity blown part in Alesis Mixer PS

Its not measuring any resistance on a multimeter either so I swapped it for a new one.
Power supply works now.I didnt leave it on for long though.
Im gonna check it again later.

[R_J]

Re: Help identity blown part in Alesis Mixer PS

It could be that the 2200 went open and the poor little .1uf tried to do the filtering and failed.
Try using diode test with your meter, that should show something, then reverse the leads and check again

[Carm99]

Re: Help identity blown part in Alesis Mixer PS

I tried that. It was the same.
Im gonna replace the rest of the caps anyway. Also those two 0.1uf ones.

[sam_sam_sam]

Re: Help identity blown part in Alesis Mixer PS

Did you happpen to check the capacity of the cap also? or just the esr? That 0.00Ω esr seemed a bit odd to me. I guess the cap could be completely open and not measuring anything

Not necessarily meaning I had a capacitor ESR reading like that and when I check the new one I got the same exact results

I was also confused as well with the results

In fact I check this capacitor with a capacitor tester that checks UF readings and it readings were what should have been but I did replace it anyway

I would check a new capacitor with same exact UF value and the same exact voltage see if you get the same exact results

[Carm99]

Re: Help identity blown part in Alesis Mixer PS

I got it working in the end ,it was the transistors.