Hello to everyone! i am new here in gearslutz (the name says it all ).
I keep following these forums and i always found very valuable information about synths, Music production etc, and for that i say THANK YOU to EVERYONE here who posts information, thoughts and opinions. Sharing knowledge is only good, never fails.
Thank you gearslutz for existing!

Now for the subject here:
I recently bought a TX7 (always wanted a Yamaha FM-synthesis hardware to fiddle with..), because i got nostalgic of my younger years at school and the music vibes of the new thing called DX7..
After i got the TX7, i could not leave it alone , so i replaced the stock display with a module with a led backlight (black on green so that it is a pair with my SY85 green display).. All went well, and i powered the LED backlight from a +5Volt connector that says "test" at the adjacent PCB.
Now i can use the TX7 in my dark studio, too !

One thing i noticed when i power up the TX7 is a short "clik" sound , like a relay is opened (i don't remember that clik when it had the stock non-lit display on).
Is this normal? Is there some kind of relay or auto-switch on the TX7's power supply that activates now that i have connected a cable at the +5volt socket?
Should i worry???

Please advise...
Thanks in advance

Hello.
I don't know the answer to your question, but I also have TX7 and I'm considering installing a backlight.
That is why I would like to ask You if the replacement of the LCD is easy or does it require some more complicated operations like soldering etc.?

I replaced my TX7 display- fairly easy to do. (this was a Display replacement- not a Backlight replacement).
The one I bought used the same push-in connector that the old display had.

Hope that is helpful.

How do you find the right replacements for each synth's display and/or backlight? Not TX7 in specific but I have older items that will eventually need them I guess

For the OP, I'm pretty sure older gear often has a click sound when started up because some sort of capacitor wears out that protects speakers from the unwanted sound

Search on ebay (or probably other places as well). Just searched for "DX7 display" and it came right up; try likewise with whatever model you have in mind

I similarly replaced my DX21 display a couple years ago, with a backlit one purchased from ebay. It did not require soldering, and came with step-by-step directions.

That being said, I would not call it an easy change: the new display re-uses the same glass front-piece, which the old display is glued to.

The instructions simply tell you to separate the glass and the display with a knife or razor, and this is indeed what you must do. What they do not say is that this will be very difficult.

1. The glue is very strong, so you must use force -- but if you slip, you may very well be jabbing said knife/blade/etc into your own hand. Be very careful.

2. The glass display is partially blacked out, around the edge, leaving the display part clear. Any slip of your knife/blade/etc means scraping that blackness off the glass.

Bear in mind that you *must* use force to get the glass off the display, but the more force you use, the more likely you are to injure yourself, the glass, or both.

Also: it's not explicitly stated, but you must save as much of that old glue as possible, because that's what keeps the new display in place. No replacement glue is offered.

Everything else about the installation is very easy: open up, undo two screws, unplug. Really. That's it. Taking the glass off the old display is 80% of the job; once you get that done (and despite being a sweaty nerve-wracking experience, I did manage it), you simply reassemble and -- voila! -- nicely lit screen. oooooo!

Just got a TX7 last month, and I'd like to backlight that as well. But doing the DX21 was so uncomfortable, I hesitate ... Maybe it was just that one unit that was particularly difficult ....

If you want to replace the displays of older gear, IMO these are the steps you should follow:
1) Identify your old display's technical characteristics like:
i. dimensions (width x length x thickness)
ii. type of display (lit or with backlight , how many characters and rows, p.e. the TX7 uses 16X1 display which is 16 characters in 1 row)
ii. the display's datasheet which also will show you the Pinout (a service manual of the gear comes handy here)

2) Datasheet of the replacement display. The datasheet will show everything you need to compare with the stock display and make a match : similar external dimensions, same pinout

In some cases soldering is required (just 2 pins or more), in other cases it needs no soldering at all, but all is dependent on the type of display and specs..

Don't worry about it, the TX7 is just a matter of 2 screws, no glue and stuff like this! the only trick is to remove the 4 plastic rivets of the metal brackets and re-use them with the new display..

For the TX7 I used this display : https://www.buydisplay.com/default/l...er-i2c-arduino
The only difference, besides that it has a backlight (TX7 has not), it is thicker than the stock display, so you must fit the 2 metal brackets IN FRONT of the display instead of the back, and make sure you put some tape inbetween so that you don't short the display's pcb .. Also some 2 mm washers must be placed between one of the metal brackets and the plastic case of the TX7 in order to align the thicker new display.
Then you connect pins 15 (+5volt) and pin 16 (GND) to a socket in the adjacent PCB of the TX7 to give power to the LED backlight.

This is the stock display (image from another site)
https://imgbb.me/images/2019/08/08/3...b00eee2b_b.jpg

This is the pinout comparison of the stock and the new display (it is a match)
https://imgbb.me/images/2019/08/08/T...ut-compare.jpg

And this is the LCD diagram taken from the TX7 service manual
https://imgbb.me/images/2019/08/08/TX7_LCD_pinout.jpg

The plastic rivets:
https://imgbb.me/images/2019/08/08/Clipboard01_ed.jpg

Power supply connection for the backlight:
https://imgbb.me/images/2019/08/08/Clipboard02_ed.jpg


Please note that the stock connector (14-pins) is a match with this particular display and you just plug it in. If you buy another display module, make sure you check and match the pin out, that's it.

I hope this helps.
(sorry for the picture links, the admin doesn't allow me yet to post pics.., so i added them as links)

But i still have this question unanswered: Should i worry about that clik sound???

Anyone??

Yes, it's fine. Just walked over and turned mine on -- same click, right after switching. Didn't think to do it earlier. Just too easy and obvious I guess But I switched it on and off a few times, and that sound happened each time, while the display (not yet backlit) came happily on -- no problems

Thanks a lot JPogo ! Now i am calm and i can concentrate on making music.

That's why i love this forum : There is always someone here to help you!

Thanks!!

BTW, i will prepare a detailed "guide" how to replace the TX7 display (with clear photos of mine), for anyone who wants to do it. Well, i will just describe what i did with my TX7.. (just want to find the time to do it properly, but i will!)

By the way, JPogo, did my information about the TX7 display replacement helped you in any way?

My TX7 also gives an audible click on power on. Nothing to worry about and mine is completely unmodified. My DX7 has an identical click on startup.

Thank you, too, astrogat0r ! Now i am double confident that all is ok!!
Thanks a lot guys!

And let's keep on playing music !!

Well, you gave me reason to consider it. I'll take a look at it, see how hard it is to get open.

Meanwhile, one of the things I like about my DX7ii: it already has a backlit screen ....

Just adding to the evidence....

There is indeed some sort of 'relay click' powering up the TX7.

I'm in the process of replacing a lot of old displays in my synths so this thread is vey helpful - thank you!

Check this on youtube --> https://www.youtube.com/watch?v=CR5cgof0slY
It is related to the battery replacement of the TX7 , but it shows how easy is to open up the TX7.

Also, from the service manual, disassembly instructions:
https://ibb.co/x6hHrmq
https://ibb.co/87b4nC6

You can download the service manual here

I hope this could help a little bit more.

So, i am not the only one here who hears cliks and claks !!!

Thanks! I'll be glad to report if things go well

Thank you for all this info. I have other old stuff (Roland Alpha juno) that will need a new display sometime. I'd probably have to take this to a tech one day

Mine gives a little click at power on, as well.

I was lucky to buy one with a backlight display already fitted.

There you go:
https://www.manualslib.com/manual/10...ha-Juno-2.html
https://www.synthxl.com/roland-juno-1-alpha/

I guess we are not one!

An idea: Probably we could sample this clicking sound and make a DX7/TX7 patch named "PWR-ON CLIK"

Indeed it does; that's the easy part. The hard part is getting the bezel (glass) off the display without damaging anything (anyone?).

Who knows, maybe I'll still try it. Right now my TX7 is in a well-lit place, so I can afford to be lazy

"Don't worry about it, the TX7 is just a matter of 2 screws, no glue and stuff like this! the only trick is to remove the 4 plastic rivets of the metal brackets and re-use them with the new display.."

LOL yeah, that's the description which sold me on trying it the first time, with the DX21. And what I found out is what I reported above

Maybe the TX7 really is easier -- if there's no bezel involved. I'll just have to be motivated enough to spend 30 minutes finding out. Maybe tomorrow ... today I've been busy researching SPX90's, and how to repair them

I am seriously considering a replacement with backlight for my TX7 so I am very interested in the details of the exchange. My TX7's current placement makes it very difficult to read the display.

Oh, ignore my whining above; it can be done, and you just ought to know that it may be a bit more difficult than the instructions indicate, but not technically so.

I see there's a black-on-green replacement now, which would match what Yamaha put in the DX7ii. And there's even a black-on-white for $10 more, although it's hard to tell from the photos if that's actually any more readable

Actually it is easier than you might imagine! Since you made it through with the DX21 , you will make it in 20 minutes with TX7 !! Seriously !!

Check this out, also :
https://www.buydisplay.com/default/b...2c-for-arduino
https://www.buydisplay.com/default/b...-adaptor-board
https://www.buydisplay.com/default/l...black-on-white

good deal -- now I feel dumb buying on ebay!