Faulty generic 5V 2A AC adaptor ('wall wart')

[tiff_lee]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

ha yeah.. I think the keyboard needs burning tbh

[stj]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

oh yea, wash that keyboard!

[stj]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

i like that supply, it's simple and clean - even has a pi filter.

i would just replace the 3 low voltage caps with panasonic FR's and be happy.
i know it doesnt have an input choke or anything, but who cares - it's tiny.

[tiff_lee]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Photobucket links dont work here? I could see them in the post ok?

[kaboom]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

photofucket, aka M$, strikes again.

Uploaded/attached to the thread:



That said, I'd just as soon crush this thing, for obvious reasons.

[stj]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

no, i dont either.

[momaka]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Am I the only one that doesn't see any pictures?

[Dumah Brazorf]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Change the keyboard too. It looks horrible!

[CapLeaker]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

change three caps (starting cap next to the PWM, and the 2 on the output) and be done with it.

[eccerr0r]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Without an ESR meter, I'd start with replacing C2 then the output caps.

[tiff_lee]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Unfortunately not only a Uni-T multi meter.

Any recommendations for one? I see plenty of cheap ones on ebay but when I searched previously I recall people saying they were not 'true' ESR meters or something?

Edit: Now reading some older threads on here regarding the ebay ESR meters

[ReeceyBurger123]

Re: Faulty generic 5V 2A AC adaptor ('wall wart')

Probably bad caps causing the fault, do you have an esr meter to check the caps ?

[tiff_lee]

Hi all,

i've got a faulty 5V 2A ac adaptor and was just looking for some pointers to identify the problem, sure I could buy another one for next to nothing but i'd rather try and fix it if only for the learning experience.

Here are some pics:




Output voltage was approx 5.3V but as soon as I connected a load (only had a 6 Ohm 50W resistor to hand) the voltage dropped to 1V even though the load current at that resistance is less than half what it should be capable of.
Given the complex PSUs some of you work on no doubt this is childsplay for many so please be nice!

cheers, Lee