Disclaimer: I take no responsibility for any damage or injury if you choose to do this repair to your own radio.
The Supersound II-series from Pinell are decent radios, but are well-known to be affected by bad-quality power supplies.
Pinell do replace faulty power supplies as long as your warranty is valid, but after that you’re on your own.
Luckily replacing the power supply is quite a simple operation if you have some electronics knowledge.
PS: In making this info-page I have found there to be at least a couple different power supplies voltages used for these series of radios.
These two versions use vaguely different power supplies, but will still require you to find the correct matching power supply.
The two models are distinctly different by watching the date-codes in addition two some design changes in the back of the radio. The model which use the first value usually has a date-marking between 2010-2013. The audio-jacks are placed vertically on top of each other. The model which use the second value has a date-marking from 2014 and onwards. This model has the audio-jacks on the bottom, placed horizontally.
The radio pictured below is the newer model (still called Supersound II)
You can and probably should find and confirm the correct voltage and power draw by reading the info on the power supply itself. Below is a picture of the power supply from a radio which use the second value.
The replacement power supply has to have one of the following specifications
Value 1: 12V, 500mA
Value 2: 10V, 1250mA
You can find power supplies matching these specifications in your local hobbyist stores (Clas Ohlson, Biltema etc) or you can use an old power supply as long as it meets the specifications above. You can use a power supply with more amps (eg. >500mA) but the voltage (eg. 12V) has to be the same. These are usually written on the case.
It’s up to you if you want to have the power supply on the inside or the outside, but for most cases having it on the outside is better. Usually people don’t have small power supplies like the one used inside the radio lying around.
To make the external power supply fit the radio you have multiple options. You can solder the wires together, if you have a soldering iron handy. You could use a cable-shoe butt-connector (pictured below) and crimp the two wires together. The very last resort is to remove the insulation and twist the wires together. Even though that would work, I don’t consider it neither a permanent or as a long-term solution.
In this case I didn’t fit the power supply because this radio has another issue with the sound, which I will try to resolve before I take use the power supply here.
If you have any questions, feel free to leave a comment below this post.