Here is part 2 of 2 of the Alpha Juno repairs. In this video I repair a section of dead keys on the keybed, replace the dim LCD, replace the battery, and upgrade the EPROM firmware on the JU-2.
Great video! I wish there were timestamps, but just in case anyone is looking, I have few of them listed below: - battery section begins here: 7:03 - reset procedure after battery replacement (check BA or check battery message shows): 10:02 - the firmware section is here: 20:22 - instructions on viewing the firmware via the controls (no need to open it up) is here: 23:19 - the display section is here: 26:55
Opened up my Juno 2 today, while watching your video. Super helpful! I'm trying to fix two dead keys, one extra loud key, and - probably not so easy - what seems like noise on the chorus. Keep up the great work!
loud keys just need to clean the contacts, the Alpha Juno is velocity sensitive, it is reacting to a max velocity key press because (probably) there is dust/detritus on the contacts@@noahjohansen3812
I fixed up one a while back, and it said Check Battery!! even though I replaced it back then. The battery was still good, actually it was the RAM chip which had gone bad. Now replaced he's working great again.
Thank you for your video, it was very helpful to do a cleanup to some keys that weren't working. I will say however that as I was removing the springs of a couple of keys I noticed that one of them was larger than the others. I couldn't see that this was related to the key of the spring being black or white so I resolve to remove all of them and see what happened. In the end I found that there were 25 larger springs, which I took corresponded to the number of the black keys. I think the keyboard perhaps was repaired by someone that didn't know the difference but at least in my case the springs were certainly different, and it kind of makes sense. A larger spring probably has less tension and having the larger spring on the black key and the shorter one on the white evens the action throughout, given their physical distance from the hand. Hope this helps anyone in the future.
I agree with you about different springs for sharps and naturals; in fact, the service notes for the JU-2 show this, with different part numbers for the black and white keys.
Hi Brad, me (and I guess many others) would love to support your channel through Patreon or the like, as your content and knowledge is just incredible! Many, many of my friends have vintage gear and I have directed them to your channel. I'd just like to give back something other than a thumbs-up or comment. Best wishes, Jann
Awesome job on fixing this bad boy up! Really nice to see a new video from you too. I always look forward to them and wish they were more often uploaded. Please keep up the great work!
Thank you for this! I have a juno alpha 2 that needs repair, the screen lights only half way but no letters just back squares, no sounds and seems like all the buttons are frozen, nothing works basically, any idea what could be? Thank you!
Thanks much for these videos! Could you please tell me what do I have to exactly search for on Ebay, for those LED replacements? English is not my mother language. Thank you!
I've had a Juno 2 from new (circa 86-ish). I just checked recently sold items on eBay and the price seems to be around £500 ($650), which is much higher than you said. But if you have a cheap source - good luck to ya' !! I was watching your video for general repair inspiration. My synth works nearly-fine, but I've lost after touch.
Soon as you started this I knew I had my answer to the group of keys not playing, and i know its going to be a biatch because the board was so clean and the creases in the ribbons were perfect plus the obvious no scuffs on any of the screws even with magnification... so i get to look at wires till i say, um .. tomorrow .. this group of dead keys is on a xp-10 and i left words on the xp 50 recap thanx!! oh yeah the xp-10 keys ar set up like your JP8000 and DONT use a screwdriver to spread the keys, use the other end of the toothbrush, its should be near perfect size,Brad here's probably popped a few hundred,do what I say ,not what I do...lol
On my Juno-2 (purchased in the fall of '87), the key return springs are not the same length. The black key springs are longer (but the shorter white key springs stretch longer in position).
Hi! Great video. Do you have any advice on testing the 30+ SPST push buttons for the front panel membrane controls? Most of the buttons on my 3rd-hand Alpha Juno 2 don't work and using a continuity tester I can see that the 2 legs on each side are connected to each other but when I push the button down the legs on opposite sides aren't showing continuity. All the diodes seem fine.
Hi. I bought an Alpha Juno 2 which is missing all the screw to hold the chassie together (under, back and sides). 18 screws are missing. Do you know what kind of screws I need and where to purchase them? Thanks
Just stopped this vid at the mention of glued in key weights and wanted to ad to the list that used the crappy red glue. The VK7! Tone wheel emulator series, although i cannot confirm all models had weighted keys, the 7 did. I got to be the lucky guy that took a dripping goo everywhere machine and turn it back into a great player/Being the bottom of the line you wouldnt think it had alot of features but it does. You can turn off the drawbar section completely and run the orchestral strings, choir ,brass, bass and more with a mixer in user sets. This-7 has full percussion section and mixable reverb as well. It also has an 11 pin socket to link to a Leslie!!! back to the red glue. There IS a way to remove it safely and effectively leaving no trace. It is time consuming and has cost plus health issues ,so I'm not going to post it here, but I will share it with anyone that attempts to convince me they can do the tedious ,time consuming job safely. Since I've done this more than once {!} I have streamlined it and will do the procedure for a fair price. I am in the sunny Southern USA. Unless you have a no children allowed space, I recommend not doing this in a family household. Sorry Brad ,didn't mean to grab any of your thunder, but felt somethin should be said
Wow, this was the video I needed to see. I really appreciate the detail you've included in this restoration. I have a Juno 2 that had some key issues, which I've fixed, but I had a question about replacing the capacitors on the power board. I'm not sure if what I'm looking at is the cap's leaking or not. Can I send you a picture and get your advise? Thanks, Mike
Found the problem, it was the white ribbon cable very dirty inside, also keybed ribbon was out of socket, I have to see if I can find that white ribbon cable, I want to replace.
My screen has zero backlight anymore so I was going to use your suggested replacement. Doesn't need to be an exact match, but as someone who doesn't really have little trimpots sitting around and would have to order one, can you recommend a value/measurement trimpot for adjusting the contrast?
Yo tengo alpha juno 2 y el problema que tiene es en el comando para el volumen. Subo la tecla y no funciona o debo ejercer presión a un costado para que funcione.Tendrías alguna recomendación para arreglarlo. Saludos
Hi Brad. I think I bought the same replacement LCD. How did you rewire / solder the wiring for the replacement LCD display? I'm not seeing where to solder the ribbon cable header on the new LCD display I'm trying to replace for my Roland JP8000. Thanks!
Hi Brad, my juno 2 still isn't working, however I have noticed that r48 is absent and r49 is bridged to pin 16 of ic8, could this be the problem as it isn't on the schematic?
Hi there Brad, haven't watched all of this video yet but I am a bout too. I got an alpha Juno 2 a few months ago and its in pristine cosmetic condition, however the aftertouch seems to be a bit faulty, the higher half of the keyboard it doesn't seem to work properly whereas in the lower half it does. The upper half you either have to press extremely hard or it doesn't work at all no matter how hard you press. This was not happening when I first bought it though. Do you have any suggestions as to what I could do to approach repairing this? Many thanks in advance. Brandon
Hi, really found your video interesting. I am currently trying to repair a ju2 all I get is 8 solid blocks on the display, any suggestions. Can't factory reset either.
What power supply you recommend that will be upgrade to and old one? European or possibly switchable between Europe/USA? I wish in a future to sometimes do and upgrade for my Juno 2 Alpha. Kind regards.
Were you not to have the PlastiGlass cleaner, what would you use? Seems to do a great job and I'd like to find something similar. What are the active ingredients, etc.
Try brillianize, its available on evilbay .An 8 oz bottle lasts forever as it is not aresol.Works well on headlights and more, after you use a cleaner like vinegar water,that dissolves bug guts....
Hi Brad, I have just purchased a spares or repair Juno 2 which has some bad problems, the psu board has actually been snapped in 2 breaking a lot of tracks, I think someone has been in there and badly put it back together as the keybed wasn't even fixed down!. I have managed to repair this and am getting the correct voltages but as of yet I have not gone any further. I noticed that the main board is only fixed by 3 screws on mine and that there are no screws for the other 3 holes of the pcb which go under the keybed, I can't quite see from your video if this is how it should be and was just wondering if it should be fixed by 6 screws? it seems a bit odd as they wouldn't fix all corners of the pcb...or if anyone else can advise. thanks!
I'm into a roland XP 10 right now and its doubtful its been opened before. I know the signs from more than just synth repair, and the key contact boards were missing screws ,but in a pattern that makes sense the way the K.C. board was fixed. another sure fire check is lookin at the holes interior. In my case it was into sheet metal and there were no threads, but certainly puttin in extra screws wouldn't hurt, just remember to check close at re-install to make sure there isn't a ground ring terminal on that screw....
Great video and thanks! I'm repairing one now that has 2-3 keys that trigger at "full velocity" when depressed. Even if I lightly touch the keys, they trigger like I hit them with more force. I need to reinspect & maybe re-clean the contacts underneath (did once) unless there's something causing this. Any insight into this root cause? Thanks again!
I'm having the same issue with one of the keys on mine. No sound until depressed and at full velocity when it does make a sound. Did you get yours sorted?
@@plimx Sorry for delay. Yes, I fixed it by removing the keybed and thoroughly cleaning the key contacts underneath the rubber pads using rubbing alcohol. I just cleaned everything under the keybed, including solder joints and the contacts. Fixed the problem for me.
Thanks you, very useful info. 🙏 My Juno is working great but still enjoyed watching this. Btw i find the aftertouch quite hard on the JU-2 what about yours? Is it normal?
My aftertouch is still working well, but the JU-2 does have similar aftertouch issues like the JX-8P. I went over a fix in part 3 of that series I think it was. Thanks for watching!
@@bradthx I have after touch issues with my Alpha - I'm off to find this video. EDIT; found, link to help others: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-WJ1c66xj8Xo.html
Hi ! good video thx. Could you update my juno(the same one) software and change the display too ? would be fantastic I don't know anybody in France who does that .(I'm in France)
Hiya bud i brought another one of these the other day but it has a weird like hum coming through the outputs very slightly its sounds very similar to a ground loop that you would get on an old p.c. On an eq, it has the characteristics of a single sine wave with no extra harmonics sitting around the 500hz to 600hz mark. Once played it gets covered up but i would like to fix it if i can do you have any idea what it could be.
