This is a JVC RC-550 mono cassette radio boombox. AKA El Deablo. It has a huge speaker and nice sound. The tape deck had 2 problems. 1: Tape speed slows down when the volume goes up 2: Tape rewind stops right away. During the restoration, I found the solution for each of them. 1: Power supply was set to 220V instead of 110V. 2: This boombox has a special tape stop integrated circuit called "HALL IC". This HALL IC acts as an electronic switch. Detail cleaning of the sensor solved the REW problem. Here is a link to the manual for the HALL IC system https://goo.gl/WypBDs Also here is a video clip that I sent to the boombox owner to letting him know that REW stopping problem was solved. You can see the magnetic sensor in this video. https://youtu.be/011gwchk6sY The rest of the work was easy. 1) Converted stereo signal to the mono signal and put signal from AUX jack. 2) Use 6 pin toggle switch to shut off the radio power when Bluetooth is on. 3) Rainbow LED to the front panel. This boombox owner is Pedro, he is a collector of the vintage boomboxes. Also he is a man who is creating the original boombox from scratch using 3D printer. There was a missing parts for the handle of this El Diablo, then he made it right away using his 3D printer. (The white color parts in the video.) Thank you Pedro for letting me to restore your precious El Deablo. ------- Donation welcome! If you like my videos and would like to donate to me for my future video making work, I appreciate your kindness. Here are coin wallets and Paypal address. Thank you in advance. https://www.paypal.me/teddyhashee358 BTC (Bitcoin): 1DQJChuaZi2bHamigZWVvKwHShsTJW9uQk BCH (Bitcoin Cash): qqe43k5hdvuzstz8zxmamn0qn6x44y4wzqj240h99n ETH (Ether): 0xaC7578787cA1964cf45b314b2ac9eB2cF876FB05 LTC (Litecoin): LNJf56cM4pRgH4G47EePCUGMQWAJLV4zyi