Roland Alpha Juno 2 Reparatur Service
5. April 2020
Roland TB-303 Reparatur Service
19. April 2020Roland Jupiter 4 Reparatur Service
Repair Roland Jupiter 4 Analog Synthesizer Reparatur Service
Roland Jupiter 4 full restortion. The overall condition was not the best. When I did the initial test and switched it on for the first time one of the fuses on the psu blew up after a minute or so. So, let`s start doing this project.
First thing I did was to find out, what made the fuse blew up on the first test. Well, it was "just" a bad rectifier. After replacing that rectifier I did a full test with a load and the psu was in good condition. Since it looked all original I decided to do a full re-cap job. Not only on the psu, but starting here.
It´s not broken, so why re-cap? Because these old electrolytic capacitors are rated for a few years only and they intend to leak or they already do or did. Like in this picture you can clearly see the dark spots aound the capacitor holes. A bit more time passing by they will harm your synthesizer if not already happened. You can also see the electrolyte coming out of the capacitors like shown here many many times before.
So after replacing a rectifier in the psu, re-capped the whole synth, replaced the batteries, refurbished all sliders, potentiometers, switches, key-contacts, keyboard, jacks, trimmers, a calibration procedure, took care about cosmetic issues (something missing?) the jupiter now is in great shape. It sounds bombastic and acts like new.
There are lethal voltage exposed in electronic devices. Unless you know what you are doing, don’t try this. If you following along, you doing so at your own risk.
I’m documenting repairs for my reference and yours.
I do synth restorations and repair with a specialty in vintage synthesizers, drum computer and other vintage gear, based in Düsseldorf, GER. Get in touch about your synth situation!
