Fixing a Sony mains adaptor.

Bendy_House

Hi all.

My 12V Sony adaptor has gone kaput - worked one day, and dead t'next.

I'm loath to chuck things out without at least giving a repair a try, and I'm fairly clued-up when it comes to stuff electrical and electronics, tho' I usually draw the line at surface-mounted components, which I suspect this will have (essentially, both my soldering iron and my eyesight say 'Non'.)

Anyhoo, I will be opening it up for a gander, but was wondering if I'm likely to find summat obvious that could be the cause, like a thermal fuse? These are, I understand, 'switching' PSUs, so may not have a trannie, the usual culprit (along with smoothing caps), but what's might I be looking for inside this jobbie?

Cheers.

(No, I won't 'cute myself).

forgotmyname

A new one is likely to be a much better option.  If one part failed its likely to have stressed other parts so a repair could be
short lived and a never ending process until you have replaced everything.

another_casualty

I’d just get a new 12v adapter and have done with it .
Possibly check on the Amazon ?

mart44

Not sure if there would be anything serviceable inside the adapter. Could it be the other end of the lead with an internal break in the wire where it goes into the plug moulding? I have a Bosch charger that turned out to be this. It was possible to cut the moulding away and shorten the wire about an inch before re-soldering it to the plug. A couple of layers of heat-shrink sleeving and a length of self-amalgamating tape made another fairly sturdy plug all in all (around £15 for a new charger).

Bendy_House

Thanks all. Yes, buying another is not a problem, and in fact I do have a replacement winging its way to me as I type.

I just like exploring, and fixing if possible. The main problem with repairs such as these, is getting the case securely closed up afterwards, as it obviously mustn't come apart in anyone's hand...

I'm pretty certain it isn't a wire break, Mart, as it's barely been used, and never under stress or with sharp bending. Can't test that conclusively, tho', until I open it!

I shall let you know what I find...

chrisw

The trickiest bit and the bit most likely to cause injury is actually getting in to it using a Stanley knife or Dremel. 

As you've already identified, closing the case securely afterwards will also be problematic. Hit it with a hammer, marvel at how little is in there and then bin it.

Bendy_House

chrisw said:

The trickiest bit and the bit most likely to cause injury is actually getting in to it using a Stanley knife or Dremel. 

As you've already identified, closing the case securely afterwards will also be problematic. Hit it with a hammer, marvel at how little is in there and then bin it.

Thanks! I appreciate both the sentiment, and the delivery

Oohmaaagawd, do I have scars on my fingers from just such tasks - Stanley knife blade stopped in its travel only by the bone... Every time I pick up a knife these days, wife leaves t'room :-(

Heedtheadvice

I too agree with the sentiment don't bin, fix where one can.

Well experienced with electronics (design through use to fix) but in these cases, Yep just bin, even though it goes against the grain!

Bendy_House

I'm none the wiser...

Interesting, tho' - the AC input goes straight to rectifiers (bottom-right, lower pic), so it's DC from then on it appears.

I guess that's what they mean by 'switching'; the DC voltage is pulsed to make the transformers work? Summat like that?

Anyhoo, it's deed.

Heedtheadvice

Looks like a problem on the board between the written text D3 and D4.

But the answer is still bin!

Bendy_House

Yeah, I ripped it apart for a closer look

What are you seeing betwixt D3 and 4?