JVC M90 power adapter

[valjo]

Hi!

I would like to ask you for some help.
I have bought JVC M90, but unfortunately it has butchered and wrong non original power adapter installed.

My question is, what kind adapter do i need? Can i use it from other similar boombox ?
I believe it is 15V, but what about Ampers and Watts ?
JVC is USA/EU version, on sticker are data: 50Hz 70W

Many thank in advance !
Best regards

 

[Superduper]

Please provide photos of what you’re talking about.

 

[valjo]

Some photos of what is now installed

 

[valjo]

Please provide photos of what you’re talking about.

done i hope it is clear now

 

[Superduper]

Ok, it is clear that your transformer is not the original one. It appears to be smaller than the original. The power supply pc board has also been severely damaged and the repair does not look good. I would not advise using a transformer from a different boombox because the RC-M90 transformer is usually larger than most other boomboxes unless it is also a large one. If you want to find a replacement, you can try something like the hammond 266N12. Datasheet is attached, but you can just google it to see if you can find it locally. The 266 series are for 230/240V areas. Although the output of 266N12 is 12.6VAC, after rectification and capacitor filtering, the final DC output will be around 20VDC which is close to what the factory original AC voltage will be. Also, the 266N12 is a single primary so it is good for your area, but if your boombox has a voltage selector, that feature will not work unless you get a transformer that has multiple primary windings which significantly complicates things. That generally is only a concern if you plan to ship the boombox to an area with 120V or 100V AC systems. Otherwise, in your area EU, I would think that a 230/240 volt transformer would be fine.

Now as for your PCB, I can't make any recommendations on that because it is unclear from the photos what exactly was done there. Did the previous user make modifications or did he just bridged broken connections? It may be worthwhile to consider whether a new PCB can be made to replace it. It may be expensive but the M90 might be worth it.

Hammond Transformers

 

[hopey]

I would use a laptop power supply and feed in the 15v dc. You can get 65w easy. Then you don’t have to worry about finding a trans that fits in the box. Laptop power supplies have good filtering and stable dc supply.

 

[Superduper]

On the datasheet included in my other post, it includes all dimensions. Find one with the similar dimension that will fit that location and choose appropriate voltage. Be mindful that after rectification and capacitor filtering, final DC voltage will be roughly 45% higher than the AC voltage so 12.6 or 14 vac will be the highest you want. Don’t worry about amps so much, because the physical size and correct voltage is more important. The amp rating is essentially dictated pretty much by the transformers physical size anyways.

 

[valjo]

Ok, it is clear that your transformer is not the original one. It appears to be smaller than the original. The power supply pc board has also been severely damaged and the repair does not look good. I would not advise using a transformer from a different boombox because the RC-M90 transformer is usually larger than most other boomboxes unless it is also a large one. If you want to find a replacement, you can try something like the hammond 266N12. Datasheet is attached, but you can just google it to see if you can find it locally. The 266 series are for 230/240V areas. Although the output of 266N12 is 12.6VAC, after rectification and capacitor filtering, the final DC output will be around 20VDC which is close to what the factory original AC voltage will be. Also, the 266N12 is a single primary so it is good for your area, but if your boombox has a voltage selector, that feature will not work unless you get a transformer that has multiple primary windings which significantly complicates things. That generally is only a concern if you plan to ship the boombox to an area with 120V or 100V AC systems. Otherwise, in your area EU, I would think that a 230/240 volt transformer would be fine.

Now as for your PCB, I can't make any recommendations on that because it is unclear from the photos what exactly was done there. Did the previous user make modifications or did he just bridged broken connections? It may be worthwhile to consider whether a new PCB can be made to replace it. It may be expensive but the M90 might be worth it.

Hammond Transformers

first i would like to thank you a lot for answer and great explanation!
Hammond 266N12 unit is good options yes, but i need to repair PCB first. One question, according to data, m90 needs 15v right ? and according to 70W it will needs around 6-8A power ? 226N12 has 12V output, will it affect radio performance ?

PCB looks total toasted/butchered, so as you said, sourcing used one or make new one is only solution. I will ask locally how much it costs to make new one. Overall radio is in quite bad condition, and i still have not decided what to do with it.....

one more question; radio has 15V jack on the back. I wonder if getting right adapter to provide power thru this jack will be the best solution for beginning ?

Thank again and best regards from Slovenia

 

[valjo]

On the datasheet included in my other post, it includes all dimensions. Find one with the similar dimension that will fit that location and choose appropriate voltage. Be mindful that after rectification and capacitor filtering, final DC voltage will be roughly 45% higher than the AC voltage so 12.6 or 14 vac will be the highest you want. Don’t worry about amps so much, because the physical size and correct voltage is more important. The amp rating is essentially dictated pretty much by the transformers physical size anyways.

oh i see you have already answered my question
Thanks