See the picture of my Pentax Camera Charger, the bloody thing has stopped working.

http://i49.photobucket.com/albums/f261/GAFFRS/Camera%20Cradle/Overall.jpg

It is able to charge both a battery and the camera itself, see top picture, 3 metal spring loaded wires in 2 places.

I've taken some measurments but I'm not too sure if it might be the transformer.

There is 240V AC coming in and going to the rectifier.

On the other side of the rectifier I'm getting 330 V DC

I'm also getting 330VDC to the top right hand corner of the flash on picture 2.

From there I'm not too sure.

The secondary side of the transformer is 0V.

The solder joints where these were going into the board were very close so I re-solder these, See + & -on the top left hand corner of pic 2, to the left of JP12. There is still a short between the + & -. I wasn't too sure which pins of the primary side to check.

I know one of the orange Secondary side cables is a bit black at the end but I think it may have been to mark it.

What are the chances of getting a transformer ???

Btw The Power specs are

Input AC 100V-240V 15VA 50-60Hz

Output DC 4.2V 630mA

Btw it was originally bought in the US.

Any help, tips or things to check for would be appreciated....no matter how stupid

Nosing at the pictures there appears a short across CD2 - middle right on the picture two... but it might be the lowish res of the pictures on my screen.

RS sell transformers if it is that (but usually these are reliable) - http://rswww.com

What voltage AC have you got accross the primary winding on the transformer?

Can you post up a high res pic of the board so I can read the chip numbers etc?

The frequency of the waveform going into and out of the transformer is probably quite high >20kHz so it could be confusing your measuring device.

Basically the input AC is rectified into DC. This then feeds into an isolated switch mode power supply. The 4 legged chip that straddles the primary -> secondry line is the feedback opto isolator to control the switcher ic (8 pin chip with one leg missing) to maintain the desired voltage.

If you trust the measuring device you are using and it gives you 0V on the primary and secondry side of the transformer then it points to a fail in the input switcher or the feedback opto isolator.

What voltage AC have you got accross the primary winding on the transformer?

I think 340Vdc, well to be honest which legs would you consider the primary side ?????

Theres 5 legs, 1 not used on the right of the black box (which shows transformer) in Pic 2. I think I tried a few variations of measurements and I was getting 340Vdc.

The other thing I was wondering was if the measurements would depend on if Battery/Camera was in places, ie see the S & T contacts.

Can you post up a high res pic of the board so I can read the chip numbers etc?

Email on way to BPM to host

If you trust the measuring device you are using and it gives you 0V on the primary and secondry side of the transformer then it points to a fail in the input switcher or the feedback opto isolator.

From the 340 Measured above then I assume this would point to Transformer.

A friends father actually had an idea, if its a thing I couldn't get the parts to fix it, he have an idea to disconnect the secondary wires and hook up a Phone Battery charger

Btw All help appreciated, and don't be afraid to correct me if wrong

Nosing at the pictures there appears a short across CD2 - middle right on the picture two... but it might be the lowish res of the pictures on my screen.

RS sell transformers if it is that (but usually these are reliable) - http://rswww.com

C02 by any chance ? it may be the way the picture was taken.

If you have 340VDC on the primary of the transformer then your input switcher or feedback has failed.

Transformers only work on AC, if you apply DC to them they just get hot and you get nothing on the other side.

Have a read of http://en.wikipedia.org/wiki/Switched-mode_power_supply that will explain how it works.

Gaff asked me to post this :

Here is the switcher (IC10) you have

http://www.tranzistoare.ro/datasheets/90/467387_DS.pdf

There is an application note in there pretty much the same construction as you have there! You need to 'scope it really.

So if IC10 is the Voltage Switcher then what is The Yellow thing 99501A doing ?