SY77 booting in a loop

Yamaha SY77 is a 16 voice multitimbral music workstation first produced by Yamaha Corporation in 1989. The SY77 is a synthesizer whose architecture combines AFM (Advanced Frequency Modulation) synthesis, AWM2 (Advanced Wave Memory 2) for ROM-borne sample-based synthesis, and the combination of these two methods christened Realtime Convolution and Modulation Synthesis (RCM).

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Re: SY77 booting in a loop

Unread post by Rara » Wed Apr 04, 2018 3:40 pm

That's OK, I didn't mind the tip :-) thanks

SY77's are starting to climb up in price here.
I got mine in 2011 for $270aud, adjust for inflation 2017 price $302aud (188eur)
now there fetching anything as high as $750 (470eur) in good working and cosmetic condition
SY99's can go as high as $1000aud (625eur) now
Not too long ago you couldn't give the stuff away now everyone wants it.

Rara
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Re: SY77 booting in a loop

Unread post by Derek » Wed Apr 04, 2018 6:58 pm

Rara wrote:
Wed Apr 04, 2018 3:40 pm
That's OK, I didn't mind the tip :-) thanks

SY77's are starting to climb up in price here.
I got mine in 2011 for $270aud, adjust for inflation 2017 price $302aud (188eur)
now there fetching anything as high as $750 (470eur) in good working and cosmetic condition
SY99's can go as high as $1000aud (625eur) now
Not too long ago you couldn't give the stuff away now everyone wants it.

Rara
As people realise what a monster they are! :D
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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Re: SY77 booting in a loop

Unread post by shadowmask » Wed Apr 04, 2018 8:19 pm

Rara wrote: while I am here, where is the Logic controller located on the main board?
"Logic controller" is a vague term, most of the stuff in the SY77 controls logic in some shape or form. Most of the signals for the LCD connect to IC140 - a low cost 74HC245 buffer chip. A couple of the others go to IC105 - a 74ALS32N OR chip. Both are still available for about £1.

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Re: SY77 booting in a loop

Unread post by Rara » Thu Apr 05, 2018 2:03 am

Most of the signals for the LCD connect to IC140
Thanks for that, I'll get that check out as well :-)
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Rara
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Re: SY77 booting in a loop

Unread post by Rara » Thu Apr 05, 2018 3:05 am

As people realise what a monster they are! :D
I am still discovering things on it :)
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
Australia
Rara
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Re: SY77 booting in a loop

Unread post by Rara » Fri Apr 06, 2018 10:30 am

I have been checking things as suggested in the thread previously,
SY77 is now showing the same behavior as it would if IC140 had failed.
No booting at all, just the back-light glowing, brief flash of the operator select LEDs
It did fail previously, when I did the first display up grade with a non newhaven display.

luckily the technician I used had put the replacement chip in a socket.

the chip in there at the moment is Phillips chip:
74HC245N
BA804 52
UnG626E

I am presently looking for replacement chips. my question is
is a texas instruments
640BN
SN74HC245N
The same chip?

thanks :-)
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Re: SY77 booting in a loop

Unread post by shadowmask » Fri Apr 06, 2018 5:05 pm

The TI chip should do the same job as the Philips one provided it is the same footprint (DIP vs smailler SMD device).

The circuit diagram suggests that the SY77 may be having a two-way conversation with the display rather than just blindly sending data to it. If the '77 doesn't like what the display sends then that may be why it keeps showing that message and graphic.

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Re: SY77 booting in a loop

Unread post by Rara » Sun Apr 08, 2018 5:17 am

Thanks for the tips.
unfortunately replacing the chip did nothing. It's a dead synth now.
Sometime in the future I'll have a tech person look at, it wont be anytime soon
as theres plenty of other dead gear to put me off.

Cheers.
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Re: SY77 booting in a loop

Unread post by EB5AGV » Mon Apr 09, 2018 4:38 pm

Rara wrote:
Wed Apr 04, 2018 11:30 am
Strange, I have never seen a screen like that in 10 years of SY/TG ownership
It was an unexpected surprise to see this screen.
I've got myself a can of electrical contact cleaner today, so when i check everything i'll clean it.
after that, as i said, my technician can have it for a while.
.....so it appears to be a genuine Yamaha message.
Thanks for that :-)

while I am here, where is the Logic controller located on the main board?

Thanks
Rara.
Well, I am getting kind of an expert opening and dismantling my SY77 (I have posted a part of the story on my WEB at: http://jvgavila.com/Yamaha_SY77_repair.htm but after that, I have done THREE times almost the whole work again; I will explain why on a later post :wink:

So, well, on the SY77 you have two large digital boards, the DF1 and the DF2, which can cause problems. But, for sure, the main CPU and what is involved on the boot (EPROM/ROM and such) are on DF1. One option you have is to buy a replacement board. I got one at eBay.fr for a mere 25 EUR some weeks ago. I was lucky, as seller had it listed for long time and he accepted my offer. There was another one for 100 GBP some days ago on eBay.co.uk

But I guess the failure could be due, if we discard the CR2032 battery, electrolytic capacitor leakage on the DF1 board. The one I got had some leakage. It is easy to remove (check my WEB page for details), clean the residue and replace the capacitors with new ones, which will last for other 30 years :) ... It is worth a try!

I have plenty of pictures of that work, if you need them. I can even give you a list of needed cap values.

Please, let us know what you find.

Regards,

Jose (SY77 disassembler :mrgreen: )
Last edited by EB5AGV on Tue Apr 10, 2018 1:29 pm, edited 1 time in total.
Jose Gavila

Yamaha SY77+SPX990, DGX660, Genos
Steinberg Cubase Elements 10, The Grand 3
Arturia Keylab 61 MkII, Pigments, Analog Lab 3
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Re: SY77 booting in a loop

Unread post by Rara » Tue Apr 10, 2018 12:53 pm

Thanks for your tips, I did see that DM1 board on ebay a few days ago,
if all else fails that will be an option as it is the only one available at the moment.
As long as the seller is happy to ship to australia. by the time that board gets here
it'll cost as much as what i bought the whole synth for. But .... you cant put a price on pleasure
or pouring out your emotions through them can you ... no ... :-)

I have been over the boards with magnifying glass, I did not see any cracked joints nor any swollen
or leaking caps. Inside it looks in really nice condition.
next step, get a capacitance meter, check all those caps, even if they look good it
doesn't necessarily mean they are. I've been meaning to get one anyway for my amps.

I will chisel away at it, it can be a tad disheartening sometimes, Particularly when you have
multiple failures all in a few weeks of each other. 8O

in the meantime here is the SY77 in action with the SY35. (with a wee bit of MC-307 and juno)
https://soundcloud.com/user-36849805/indigo

giving myself a bit of pep talk to fix it ;-)

Cheers.
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
Australia
Rara
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Re: SY77 booting in a loop

Unread post by Rara » Wed Apr 18, 2018 8:31 am

Hi,

I dropped off my sy77 to the tech, he'll check the whole thing over
and replace all the front panel tact switches. it'll be a few weeks before
I know anything. He's busy :-)

Rara
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Re: SY77 booting in a loop

Unread post by EB5AGV » Wed Apr 18, 2018 8:50 am

Rara wrote:
Wed Apr 18, 2018 8:31 am
Hi,

I dropped off my sy77 to the tech, he'll check the whole thing over
and replace all the front panel tact switches. it'll be a few weeks before
I know anything. He's busy :-)

Rara
I would also ask for the three sliders (two VOLUME and DATA ENTRY) replacement, as the work is almost the same once you get the PCBs out to replace the switches and for sure they will need replacement now or soon. Also, I would be sure the switches they are going to use are good brand ones. I used OMRON B3F1002, bought on Farnell, and they are lots better than the generic chinese ones.

I did on mine all that work and it takes some hours but, definitely, it is worth the effort. Now all controls work flawlessly and it is a pleasure to use :D

Please, keep us updated!

Regards,

Jose
Jose Gavila

Yamaha SY77+SPX990, DGX660, Genos
Steinberg Cubase Elements 10, The Grand 3
Arturia Keylab 61 MkII, Pigments, Analog Lab 3
Australia
Rara
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Re: SY77 booting in a loop

Unread post by Rara » Wed Apr 18, 2018 9:11 am

thanks for the tips, i'll send another mail to my tech in a jiffy :-)

one thing occurred to me, this not booting up reminds me of a DX-7, that can do the same thing.
when one of those 9mhz crystals fail (cant remember what there called). DX7 dos the same thing, powers on
with a blank display.

Rara
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
Australia
Rara
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Posts: 304
Joined: Sat Jul 07, 2012 4:34 pm

Re: SY77 booting in a loop

Unread post by Rara » Tue May 22, 2018 2:13 pm

Hello,
A quick update,
Not much to tell at the moment, I checked my techs work notes,
So far it is down as a complex issue and needs more time.

Rara :-)
Yamaha: SY35, SY85, TX7, PSR 4600 - Roland: Juno106, MC307, MKB200
Kawai: XD5, Korg: Poly800Mk2 (moog slayer mod)
Digitech studio 400
Tascam Porta 5 HS, MM1, Studiomaster: Fusion
Modded SX Bass, fat wires, Dimarzio DP250 pickups, Ernie Ball strings / Gliga 1

To be resurrected: SY77,FZ1,CZ1000,CZ5000, MKB200
Retired: Dr550mk2,SE-70,SR-16,D110
Boat anchors: ESI2000 :angry-banghead:
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Re: SY77 booting in a loop

Unread post by Miks » Tue May 22, 2018 2:29 pm

Thanks for posting a (kind of) reliminary result - I'll keep my fingers crossed that your tech will be able to solve the issue(s). 0-)
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
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