Sony boombox model cfs-b11 transformer

http://boomboxery.com/forum/index.php/topic/23020-my-2nd-sony-cfs-88s-project-better-sound/

Hi Bart,
You will find there is a specification plate on the rear of the unit.
It should have a rating on it showing the wattage of the unit. This is usually the amount needed to operate all the functions of the boombox.
The wattage is your input voltage multiplied by the current draw in amps. So the amperage is the rated wattage of the unit divided by the input voltage.
Usually all power goes through the transformer, so I would use this input amperage as a guide, and assuming there is no power loss, use the same calculation for the output - you know it is 9 volts, so the wattage going to the unit is the same as the input wattage, so you can calculate the amperage from this.
Transformers usually work on AC input/output, so there will also be a rectifier to convert the AC to DC for your boombox.
I would add 10 - 20% above your calculation to make sure you have sufficient power. Also I suggest that you install a fuse between your transformer and the boombox for safety.

If and this depends on brand and model number, the output transistor is shorted confirm the voltage from it to the transformer and if being held down or High voltage only comes up to 5 or 6 thousand volts the flyback is suspect.

Most shops of course have a ringer which will with part out of set test the primary winding (one that goes to and from the sweep transistor).

Some models are more prone to bad transformer than others so look at the history of this brand/model.

A bad one will usually take the sweep transistor out sometimes repeatedly--but other issues in for example the driver circuit in some models will cause the transistor to pull excessive current and get hot very fast---not usually the transformer.

The SMPS sounds as if it is OK. The line output transistor has probably failed and maybe the transformer. Before leaving it as repaired, check the tuning capacitor across it and check the 135volt HT line for stability.
Hope that helps.

Tv repairs shops carry a selection of power supply cords, also check out Radio Shack Stores.

Hello

The horizontal output transistor number for Sony KV-ES34M61

Horizontal output - [Q6807] == 2SC5480-01
Pin output - [Q6808] == 2SC5480-01 Again

Please replace bothe the transistor at the same time. Check horizontal output transformer [LOT of HOT], for any defects.. Ok

The adapter is an AC-905. The important bit is the 500 mAmp. The actual part number is 169301611

More than likely there is a voltage resultor in the circuit that will take the 24V input and convert it to 9V internally. This voltage difference is not necesarily a problem. What is the problem with the unit that is causing you to check the voltages?

Dan

usually the horizontal output is shorted due to loose connections on the transistor, driver transformer, or driver transistor. this will cause failure of 2 power transistors in the low voltage supply and open up a low ohm circuit protector. any reputable shop can repair this for a fraction of the replacement of the set. and the repair lasts.

Yes, you should check other parts. The horizontal output transistor is more than likely shorted. Also the flyback could have gone bad. Some SONYs have problems with the horizontal driver transformer which is connected to the base circuit of the horizontal output transistor. If this little transformer has a loose solder connection, it will take out the horizontal output transistor. This may give you some insight as to where to look for your problem. Stargazer