SY85 PSU repair or replace w used part??

The Yamaha SY85 is a digital music workstation introduced in 1992. Unlike other Yamaha synthesizers of the time (SY77 and the SY99) the SY85 does not use FM synthesis. Instead, its sounds are based on samples, which can be layered and modified to create new sounds.

Moderators: Derek, parametric, Saul

User avatar Austria
Posts: 1
Joined: Mon May 06, 2019 4:40 pm

SY85 PSU repair or replace w used part??

Unread post by peacefulpat » Mon May 06, 2019 4:49 pm

Does anyone have an idea how I can repair or replace my internal power supply in SY85 when Yamaha says it has no spare part available anymore?? It worked perfectly and then suddenly would not turn on. The repairman says the internal PSU has Short Circuits (Kurzschlüsse) and Interruptions (Unterbrechungen) of specific Transistors und Diodes, that these can not be you have any experience with this? Or how I can get a used spare part PSU? Many thanks for your help!
User avatar Germany
Specialist Moderator
Specialist Moderator
Posts: 1888
Joined: Fri Oct 31, 2008 1:00 am

Re: SY85 PSU repair or replace w used part??

Unread post by Miks » Mon May 06, 2019 10:34 pm

Hi peacefulpat,

welcome to the forum :D

A SY85 needs these 3 voltages to operate: +12V (150 mA), -12V (150 mA), 5V (2.8A) - see pic:
SY85 - PS.jpg
As an example:
the All PSU Model: SRP-25-3001 (+5 Volts (3 Amps) +12 Volts (1.5 Amps) -12 Volts (0.5 Amps) will satisfy your needs in regard of the voltages' specs. But be aware that this PSU is NO drop-in replacement! Some soldering work may be required to get this working with your SY85. A good technician should be able to do this!
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500, TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Ireland
Site Admin
Site Admin
Posts: 11728
Joined: Sun Feb 01, 2004 1:00 am

Re: SY85 PSU repair or replace w used part??

Unread post by Saul » Tue May 07, 2019 2:06 am

Thanks for posting that info Miks and as you say any good tech should be able to sort this out without much trouble :)
Site Admin
Subscribe To Our YouTube Channel!
Review on Trustpilot
Sign up to the Newsletter
Follow us on Twitter @YamahaMusicians
Follow Us On Facebook
Follow Us On Tumblr
Dowina Acoustic Guitars: Dowina Cabernet DC
Dowina Chardonnay GAC DS - Dowina Rustica GAC - Dowina Marus - Dowina Puella

CASIO PX-S1000/Vintage VE2000GG Gordon Giltrap/Ibanez AE245/Arturia Keylab 61 MKII/Arturia Analog Lab 3/Arturia Piano V2/Pianoteq 6 Pro/Apple iMac 27"/Logic Pro X/Ableton Live 10/Behringer QX1202USB Mixer/Presonus Eris 4.5 Active Monitors. Makro Racer
User avatar Cayman Islands
Global Moderator
Global Moderator
Posts: 349
Joined: Tue Oct 18, 2011 11:54 pm

Re: SY85 PSU repair or replace w used part??

Unread post by jima » Tue May 07, 2019 8:28 pm

Moved to SY85 forum where it may get more exposure.
Yamaha EX5, AN1X, TG500, Moog Werkstatt, Korg Wavestation SR, Sigma, Legacy Digital, Nord Modular G2, G2 Engine, Focusrite PRO 40, MIDISPORT 8x8/s, Uno, Arturia BeatStep, V Collection, Pigments | Love keyboards but so little time :(
Post Reply

Return to “Yamaha SY85 Forum - Covers the SY85 Keyboard and TG500 Module”