Can anyone recommend replacements for the following parts in the power supply in my Juno-106?
Bridge rectifier D5, part 2B4B41. I’m thinking 2W04 or maybe NTE5312?
Bridge rectifier D6, part 1B4B41. I’m thinking 2KBP01?
Many thanks!
Hi, try giving Armen’s a call. Armen’s sells & repairs vintage synths, samplers, drum machines. If anyone can fix it it’s Armen. He used to do repairs at Rogue Music also a great shop for vintage keyboard, samplers, drum machines and repairs. Check these both shops, google for the contact info. Both shops are located in Manhattan, New York. Talk with their tech staff. They’re also both very experienced. Tell them Mike Dulsky from Electronique Workshop Studio in Brooklyn N.Y. recommended them. P.S. don’t worry… I was able to find a newly refurbished power supply for my Ensoniq ASR 10. I was bugging out when I discovered the power supply was dead. Now it’s back up and running 100% your Roland Juno 106 will be soon too. Stay positive 
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D5 2B4B41 That part is a 100V 2amp bridge rectifier. It will only work if you are in Japan. it will smoke if used in North American power, and explode if used in Europe.
Your NTE parts will allow too much current, and still be over voltaged, eventually failing…
Where in the world are you located?
First you need to find out what the power supply you have installed is set for in world voltage, then find out what components are installed to find out what else you will need for parts.
just swapping the bridge rectifier is not enough to prevent destruction of critical ic chips in your unit. You should take it to a shop that knows how to do power supply modifications. Even if you are in Japan, your bridge rectifier failed due to too much current going through them, which is almost always failing capacitors. You have more than one issue.
Thanks for trying to help. I agree that failing electrolytics in the power supply can allow current to leak to ground, overloading the power supply (transformer, bridge rectifiers, regulators, transistors).
I’ve already replaced the 15 electrolytics in the power supply. None had failed, but electrolytics have a practical life of about 20 years. Things are working well. I presently have no issues. I’m looking at replacing the components I listed in my post not because they have failed, but just because. Sometimes with vintage components you can find NOS replacements, other times you have to use functional replacements. With NOS replacements, you risk counterfeits. With functional replacements you risk using a part that should work, but sometimes find that it doesn’t. Maybe the best advice is if it’s not broke, don’t fix it. Anyway, I was asking for advice for functional replacements on the parts I listed. As for D5 2B4B41, it’s the rectifier for the 9.5 volt secondary on the PT. It will never see 100 volts. The parts I asked about match the components on the power supply, which match the schematic in the SM. But thanks again.