Schematics for the PSU

The EX5 features a unique Extended Synthesis system which incorporates a number of advanced tone generator technologies. AWM2, AN, FDSP and VL. The EX5 is one of the best keyboard Yamaha ever produced.

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suchenderxxx
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Schematics for the PSU

Unread post by suchenderxxx »

Hi,

i have an defective PSU on my EX5. In the Service Manual there is no schematic of the PSU. Can someone help me out with that?

The PSU keeps blowing the first Fuse. Maybe someone got an similar problem?



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Derek
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Re: Schematics for the PSU

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Hi,

I had exactly the same problem. No circuit diagram for the PSU exists as it was a 3rd party PSU that Yamaha brought it. Neither Yamaha nor their approved repairer will support the PSU.

I traced the fault (at least) to a short circuit diode (cause or effect?) which we could not identify (can't remember the details now). I made some guesses as to what it might be and got some equivalents, but no joy.

At that point I made a chance discovery that the A3000 Sampler uses the exact same PSU. You can pick them up on eBay for Peanuts (and get the ASIB1 card you can sell on and recover your money). So that is how I "fixed" my PSU.
Regards
Derek Cook

http://www.carregddu.co.uk
http://www.echoes-music.co.uk
http://www.xfactory-librarians.co.uk
http://www.ex5tech.co.uk

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suchenderxxx
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Re: Schematics for the PSU

Unread post by suchenderxxx »

thanks derek. The PSU from the A3000 is an option. But if possible fixing the psu is better. So i want to try it.
As many Ex5 had psu problems maybe someone got the same symptoms and fixed it? So at least i know where to look at.

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Miks
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Re: Schematics for the PSU

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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), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade

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Derek
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Re: Schematics for the PSU

Unread post by Derek »

suchenderxxx wrote:
Tue Jul 18, 2017 3:39 pm
thanks derek. The PSU from the A3000 is an option. But if possible fixing the psu is better. So i want to try it.
As many Ex5 had psu problems maybe someone got the same symptoms and fixed it? So at least i know where to look at.
Hi. Yes understand how you feel. Would have loved to repaired mine, but drew a blank on what that particular diode was (many hours of searching proved fruitless), and switched mode supplies are so complex, I lose interest in them pretty fast (digital electronics is more my forte than analog). I came to the point where my time was more precious to spend on other things and had to get the EX5 back in service for gigs, so the A3000 route was the path of least resistance for me at the time. I still have the old PSU (and a US sourced PSU for spares) and I intended to fix at some point, but never had the time, and will be retiring the EX5 from gigging soon - probably swap for a rack variant and sell the two boards I have.

If you want to make me an offer for one non-functioning PSU, plus the one I sourced for spares, along with a pile of components I traccked down, then PM me and we will sort something out.

Keep us posted as to how you get on.

PS here is my original post, identifying the culprit diode

viewtopic.php?f=29&t=8352
Regards
Derek Cook

http://www.carregddu.co.uk
http://www.echoes-music.co.uk
http://www.xfactory-librarians.co.uk
http://www.ex5tech.co.uk

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