New Screen Replacement Option

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).

Moderators: Derek, parametric, Saul

User avatar
acemonvw
Posts: 2
Joined: Mon Mar 06, 2017 8:30 pm

Re: New Screen Replacement Option

Unread post by acemonvw » Sun Mar 12, 2017 8:17 pm

Hi greensweater,

Thanks for the help. I eventually was able to purchase one pre-made (apparently no soldering needed) by someone on eBay. This might be ideal anyway, as it leaves the unit as unmodified as possible (which makes it easier for a new owner able to make whatever mod they would like).

I was going to purchase everything after I knew what I was doing, but this did seem the best method for me. I've already dismantled the SY77 once to fix sticky keys, so now I'm a little more confident when it comes time to replace the display!

Perhaps I'll make a video showcasing every step of it (although it will be based on a 'pre-made' display, rather than the one everyone is buying here).
User avatar United States of America
Tristana
Posts: 3
Joined: Thu Nov 23, 2017 5:05 pm

Re: New Screen Replacement Option

Unread post by Tristana » Thu Dec 14, 2017 4:06 am

Hey- just wanted to thank everyone here for your suggestions and Derek's guide. My SY77 is now rid of the irritating whine it had before and can rightfully serve as my master keybed.

One roadblock I hit along the way was that the ribbon cable I was using to connect the new LCD was oriented opposite of the one soldered to the stock screen, and I ended up connecting it to the new LCD backwards.. Lacking a dremel to just cut off the orientation nub from my cable, I ended up disassembling and reassembling the whole thing a second time to flip the ribbon cable around on my new LCD.

Annnnnd- after all was said and done, I realized I'd made another mistake- leaving the protective plastic on the new LCD x.x
Image

For the moment, my back is asking me to leave it as is, though I may reassemble the keyboard a third time in the future. I'm surprised I did it once!

It does seem like I'll also need to swap out a different resistor at R158, I went with 5.76k but the contrast pot needs to go all the way to the left for the pot to be visible.

One last thing- I ordered the black-on-white module suggested, but it's still very much the drab black on dim green that my prior screen was. Might there be something faulty in my SY77 causing this (some backlight power issue?), or is this attributable to misleading marketing or being sent the wrong part? Advice is appreciated!
User avatar United States of America
Tristana
Posts: 3
Joined: Thu Nov 23, 2017 5:05 pm

Re: New Screen Replacement Option

Unread post by Tristana » Thu Dec 14, 2017 8:10 am

Decided to open it up and remove the plastic, and while I did so I decided to move the 5v line to the A & K points on the LCD rather than pins 21 & 22. No luck with that on getting the back light to work, though.

...And then I realized that the red wire I'd soldered to 'A' was connected to what was indicated as negative on the PCB for CN118. I can't just reverse the plug due to the plastic guides, and I don't want to damage it by attempting to reverse the wires there. Time to disassemble and reassemble everything again, tomorrow!
User avatar Wales
Derek
Global Moderator
Global Moderator
Posts: 4540
Joined: Fri Dec 07, 2007 1:00 am
Contact:

Re: New Screen Replacement Option

Unread post by Derek » Thu Dec 14, 2017 9:03 am

Hi,

That is bad news, but at least you'll be a dab hand in SY disassembly and reassembly. :D

Regarding the backlight, it might be a simple polarity issue. If you look at P15 of my SY77 guide you can see that I had a similar issue when doing this upgrade. A volt meter (if you don't have one then a basic one is not expensive) will quickly tell you the polarity you are getting.

Let us know how you get on.
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
User avatar United States of America
Tristana
Posts: 3
Joined: Thu Nov 23, 2017 5:05 pm

Re: New Screen Replacement Option

Unread post by Tristana » Thu Dec 14, 2017 7:18 pm

It was in fact a polarity issue. I seem to have overlooked the part of your guide where you made red negative and black positive- as well as the part about having a stiff drink!

Rather than disassemble everything once more, I decided on a kludge. Some cable surgery would have to be performed.

The cable actually connected to the LCD didn't have much give to it, so I decided against giving it an incision, rotating the connector head and soldering it back to gather. I instead made use of the unused inverter connector, using some electrical tape to keep things insulated.

Image

And, tada! A new, silent LCD with a functional backlight in my SY77. Thanks again everyone!

With the backlight, the contrast all the way down is right on the edge of what I'd considered comfortable viewing- so I'll likely change out R158 again at some point.
User avatar Wales
Derek
Global Moderator
Global Moderator
Posts: 4540
Joined: Fri Dec 07, 2007 1:00 am
Contact:

Re: New Screen Replacement Option

Unread post by Derek » Thu Dec 14, 2017 7:51 pm

That's great news. I prefer the cool blue display myself, but yours looks pretty good as well, and a much better LCD than the stock one. :)
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
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 1804
Joined: Fri Oct 31, 2008 1:00 am

Re: New Screen Replacement Option

Unread post by Miks » Fri Dec 15, 2017 12:59 am

Well done Tristana - looking good (Y)
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 Italy
Zanna1983
Member
Member
Posts: 13
Joined: Mon Feb 05, 2018 9:38 pm

Re: New Screen Replacement Option

Unread post by Zanna1983 » Tue Feb 06, 2018 10:10 am

Hi guys,

Now it's my turn! I just purchased a SY77 with a perfectly working original display but.... since i need to fix a couple of slow keys, I decided to purchase and install a white on blue screen from buydisplay.com. Now i'm waiting for it! I will post some pictures when completed!
User avatar United States of America
biscuitdough
Posts: 1
Joined: Sat Dec 15, 2018 10:39 pm

Re: New Screen Replacement Option

Unread post by biscuitdough » Sat Dec 15, 2018 10:50 pm

A tech recently installed a white on black buydisplay.com display on my SY77. My SY77 is now practically ruined. The display is bright in some spots and dim in others, and the viewing angle is very limited. I worry that the display is malfunctioning, or has been configured improperly, and may cause damage later.

Has anyone used the white on black from buydisplay.com successfully? I'm wondering if that model is incompatible, or if the tech just made a mistake.

Alternatively, has anyone tried a MIDAS display? These support 5 volt operation. I would prefer not to add more flying leads and/or circuit board modifications, which I would need to do in order to use a Newhaven unit.

https://www.newark.com/midas/mc240064gd ... p/59AC7146
Sweden
ledan
Member
Member
Posts: 98
Joined: Sat Jan 21, 2012 8:41 pm
Contact:

Re: New Screen Replacement Option

Unread post by ledan » Fri Jan 04, 2019 2:38 pm

B.d

I use the black/white one from buydisplay without any issues. Do you know if your tech used a fixed resistor or a variable one? I use a variable and i had to tweak it a bit to get good results.
User avatar United States of America
Niroke
Posts: 2
Joined: Wed Jan 09, 2019 1:51 pm

Re: New Screen Replacement Option

Unread post by Niroke » Wed Jan 09, 2019 4:40 pm

I attempted to swap the display in my TG-77 last night using a Buydisplay model (see link) and following the guides posted here. This unit was given to me by a friend who said the screen was bad, not just the backlight, but blacked out and unit would not boot. I checked the PSU and everything measures properly (within 300mV).

https://www.buydisplay.com/default/cata ... M24064FS-1

When I powered up the unit, I got a bright but nearly full screen, all pixels dark, except for a horizontal line about 1/3 of the way up. After several power cycles, I got another pattern, and finally another which I got a photo of.

Image

Anyone have any clue what to check next?
Attachments
BBDA0C6A-B0E7-4CBF-9F78-0FA51CA4CC7F.jpeg
User avatar United States of America
Niroke
Posts: 2
Joined: Wed Jan 09, 2019 1:51 pm

Re: New Screen Replacement Option

Unread post by Niroke » Wed Jan 09, 2019 5:52 pm

Furthermore, that image appears to be blue on white, not black on white
User avatar United States of America
EX5_etc
Senior Member
Senior Member
Posts: 562
Joined: Sun Oct 22, 2006 12:00 am

Re: New Screen Replacement Option

Unread post by EX5_etc » Wed Jan 09, 2019 6:20 pm

It was March of 2006 when I did the first blue display upgrade on the SY99 and published just a few pictures and minimal instructions on EX5tech.com that is now dead. I am glad to see that people still try to upgrade their displays. I am not glad to read about their problems.

I took it upon myself to install a new Black and White display on the SY99, replacing the blue one. Just because I have some time to do it, not for any other reason. The B/W 240x64 LCD from BuyDisplay.com is NOT completely compatible with the SY99. This manufacturer as well as others have made a change on the LCD board that should not have been made. It is a change that can damage the display or the synth if you try to just drop it in as a replacement for the old display of the SY99/77 or TG77.

I have the display on the bench right now because there were two parameters to be adjusted in order to actually have a real B/W view: contrast and backlight intensity. Without the proper intensity you don't get real B/W, it mostly looks dark purple. We are talking about white letters on black background, the opposite looks terrible in my opinion. I took various measurements that will be posted on a new thread I plan to start after the modification is done. Without going into details I will say that a 3.3V regulator is required and a pin must be removed somewhere.

I hope you can wait for a few more days so that I can finish the upgrade, take pictures and do a basic write-up. You will not have to go through all the steps that Derek describes in his guide, except of course taking out all the guts of the SY99 or other synth you want to upgrade. The display PCB will be modified BEFORE it goes into the synth and nothing needs to be modified inside the synth except of the old inverter board that can be removed.

Regards,
DrF
Motif XF6, DeepMind 12D, MicroArranger, MicroKorg S, SY99, SY85, QS300, PSR1000, WX5, EX5R, A5000, TG500, TG55, RM50, QY700, QY100, QX5FD, MDF3, MJC8, EMX2, YDP2006, REV500, EMP700, EQ500U, MCS2, AW16G, Axiom Pro 49, AKAI Pro Advance 49, Arturia KeyLab mkII 61, and a few other things by Behringer, Evolution, Philips, Tascam, Technical Pro, Yamaha, etc, etc,... I wish I had time to use all this stuff; I am not even pro. :-)
User avatar Kiribati
tux
Senior Member
Senior Member
Posts: 1190
Joined: Wed Oct 10, 2012 1:42 am

Re: New Screen Replacement Option

Unread post by tux » Sun Jan 13, 2019 1:59 pm

I'm looking forward to this, since I still haven't mounted my BuyDisplay.com LCD that I bought a few years ago.
My Yamaha RM50 page
My Yamaha synths: RM50, TG77, TG500, EX5R, CS6R (with PLG150-AN and PLG150-DX)
User avatar United States of America
EX5_etc
Senior Member
Senior Member
Posts: 562
Joined: Sun Oct 22, 2006 12:00 am

Re: New Screen Replacement Option

Unread post by EX5_etc » Mon Jan 14, 2019 4:52 am

It took about 5 hours to remove 120 screws, take almost the entire guts out of the SY99, replace the BLUE display with the BLACK one and put everything back together. The SY99 is really intimidating when you see all its guts out and you tell yourself that you have to put everything back together without using the service manual, even though you have one.

Anyway, here is the result:
BLK_LCD.jpg
The picture was taken looking at the display from the top, not from the side where usually the performer is seating. If I look at it from that angle it is not very black, it has a lighter color.

I am still not 100% happy with it because it looked better on the testing bench. I'll have to check the voltage divider values that control the negative voltage supplied to the LCD. I tested the display with my own external voltage divider and forgot to emulate the exact one found inside the SY99. I am getting old I guess, but at least I put the thing back without the freaking manual. So, I still got a working brain, lucky me. :)

I'll do a little more testing and then write-up the long description and start a new thread with more pictures, diagrams and details. I also took pictures showing the process of putting the SY99 back, hoping that one day I may attach a guide to that new thread I'll start. The thread will only have the details about the Black LCD from BuyDisplay.com initially, not how to take the SY99 apart and then put it back together. I think someone must have already done that.

All the best,
DrF
Last edited by EX5_etc on Mon Jan 14, 2019 5:11 am, edited 1 time in total.
Motif XF6, DeepMind 12D, MicroArranger, MicroKorg S, SY99, SY85, QS300, PSR1000, WX5, EX5R, A5000, TG500, TG55, RM50, QY700, QY100, QX5FD, MDF3, MJC8, EMX2, YDP2006, REV500, EMP700, EQ500U, MCS2, AW16G, Axiom Pro 49, AKAI Pro Advance 49, Arturia KeyLab mkII 61, and a few other things by Behringer, Evolution, Philips, Tascam, Technical Pro, Yamaha, etc, etc,... I wish I had time to use all this stuff; I am not even pro. :-)
Post Reply

Return to “Yamaha SY77 Forum - Covers the Sy77 Keyboard and TG77 Module”