Kurzweil K2000R K2500R Repair - Part 2 LCD and Power Supply

Continuing the K2000R repair, I replace the LCD backlight and work on the power supply.

[@Cubik303]

So glad to see you keeping these old Kurzweil tanks alive. Top engineering through and through and superb sound quality even by 2020 standards.

[@tonyjackson5261]

I don't have a Kurzweil but definitely want one. I had the K2000 keyboard and was a dummy to sell it. young at the time. Thanks for this, you've inspired me to start repairing some old 80s equipment myself.

[@10314347]

Thank you again for this series. I am learning a lot. Always loved the Kurzweil stuff.

[@Dr.Nagyonfaj]

Very interesting information. Please, if I might trouble you - would you mind putting a link to those EL backlight strips. I searched online, but couldn't find ones like you had.

[@matrix12x]

Great video! Really enjoying the series. I have a K2000R.

[@backlightsnew]

For an led upgrade, you can make the screw holes elongated for the k2000r as you mentioned come standard in the 2500. It’s another solution instead of cutting down the standoffs

[@radicalfreq]

Awesome!

[@flintmartinez1565]

Perfect timing..I’m dusting off my k2000 to go active..needs a backlight as well as an update..thanks for uploading this content..I’ll be watching for more..

[@bradthx]

Thanks for watching Flint!

[@kimmairdiscovery1957]

I got my K2500R for a few years, and enjoy it extremely. - I had to put it into storage when I renovated my basement, and after trying to power up the unit, had to discover that there is no sound. - It passes all the boot up, and hard-reset and what not. - LCD is great, all the functions seem to be working... JUST NO SOUND. - Obviously the batteries were exhausted, and when I replaced them had to discover that one was leaking (a little). Didn't think much of it, but eventually decided to open up the case and investigate. Much to my surprise there is modified wiring in my unit!!! - The main one I am worried about is the RED wire that has been added to D11 (next to TP16) and the BLACK wire attached to U58 (gnd). - The plug powers up the engine board (p/n 0011055 rev k) at J920. -=- So my first quesstion is... where do these wires originally come from? -

[@ShallRemainUnknown]

Did you try doing a HARD reset? Immediately upon powering unit, press Exit button an few times during boot process, it will bring you to boot loader menu where you can hard reset, run diagnostic tests, and more.

[@kimmairdiscovery1957]

@@ShallRemainUnknown Thanks for the quick reply. - I think I did, but I can try it again. Right now I'm going ot replace the one "transistor/power regulator, since it is running hotter than the others (checked with thermal-imager), and then ...keep my fingers crossed.

[@kimmairdiscovery1957]

@@ShallRemainUnknown I replaced the transistor/voltage regulator on the heatsink (the center one with the extra wires soldered to it) and reassembled the unit. - Unfortunately I still don't get a read out on the LCD - Its just "white". - I tried the "exit" button to access the boot loader, and ... nothing. - So now I'm into checking the boards and follow the trouble shooting from KW. - If there are any Hints or "known issues" on where to focus my diag, I'd gladly appreciate to speed up my process. The board(s) visually all look good, and have no signs of discoloration or other questionable signs.

[@ShallRemainUnknown]

@@kimmairdiscovery1957 I suggest you join Kurzweil K2x groups and ask, there's groups.io/g/KurzList and 3 or 4 Facebook groups as well. Good luck! I have a K2000R that doesn't boot, with all positive LCD that I'm trying to fix...

[@JohnSk82]

I have a K2600X and man that fan noise drives me crazy . Any idea where could i get spare parts ? I have a broken plastic side and a couple of keys are not playing due to shipping accident.Awesome video man

[@sqmus]

Great video. Thanks for this. Question: When I fired up my 2500R last year, after about 5 years of being packed away, the display came up so bright it was only readable from an angle. I could barely discern the text. I just turned it on last week again, for the first time since, and now the display just shows a blank glowing blue screen, with no text visible at all. Is this what a backlight failure looks like? I removed the front panel, and the layout of the 2500 is different from the 2000 that you show. The display looks to be in a metal case, that is not as easily removed as the 2000. Is there any chance that you could demonstrate the same procedure on the 2500R?

[@michaeljoyce9184]

Hi great video. First I’ve seen regarding kurzweil Power supply issues. I wanted to ask if you don’t mind. I have a k2000v3 that packed up Two small glass fuses at the back of the machine where the kettle lead plugs in have blown . I read to replace the large capacitor No idea really not a tech guy And synth techs in uk are not interested in repairing my machine Any ideas why the two fuses have blown Cheers mick

[@ericortiz2270]

Thanks for posting this series! I appreciate all the great info. Do you know where I can find the replacement EL backlight strips that are the right size and sell for a "couple dollars a piece?"

[@ShallRemainUnknown]

Aliexpress sellers have them, double check the dimensions, but I believe they can be cut down a bit if necessary. You'll have to buy multiples to get the best deal, as the shipping price goes up only slightly when buying more. I think the best price I found was about $24 for 6 EL panels shipped. Check different sellers for shipping prices, the best deal seller priced the panels slightly higher, but shipping was lower when increasing the quantity.

[@jameshodson3450]

@@ShallRemainUnknown Do you have a reference number for those? I've been searching Aliesxpress for an hour now and just can't find any... many thanks!!!

[@Dr.Nagyonfaj]

@@jameshodson3450 Yeah - me too. Can't seem to locate them. I've asked bradthx if he'd mind giving us a link.

[@iMacJames]

Hey all. I found the dimensions of the old backlight, which is 1.85 in x 6.18 in. I found the product "MagiDeal ABS Plastic EL Lamp" on AliExpress as a replacement backlight. It was around $2-3 dollars. The blue one is the correct dimensions, but the white one seems to be a bit smaller, but I ordered both just to test both out. Jeroen Oldenhof has a great guide on retrofitting one of the LED backlights if you want (instead of paying $90 bucks for the eBay seller backlights). They're about $30 bucks if you click the link in his blog post. Just search "Kurzweil K2000R display retrofit" on Google to find it, its the first result. (Don't want to link it here to get my comment flagged for spam) Edit- I got my replacement backlight strips today. The white ones are quite a bit smaller, so if you are doing this repair I would go with the blue ones from AliExpress.

[@yoiksandaway]

I'm trying to fix the display of my Kurzweil PC3 with a new LED backed display just like you show in this video. My old unit had a really dim CCFL backlight. I replaced it with the new LED display but the new units backlight isn't working at all. Can I get your thoughts?

[@vacmauro58]

Hello given your experience if possible I would like to ask you a question: I have a Kurzweil K.2000 VP 3.87, the keyboard (the keys) are however very "soft" when I touch the sound, I ask if it is possible to replace the keys with other semi-weighted ones, for example for example with those like Yamaha DX7II fd, Korg 01W, or with other brands; thanks if you want to answer me.

[@alteredst8tes]

i have 2 of them will you fix them up for me

[@Cinepobrefilmfestival]

my k2000r has to initialize effects etc every time i turn it on : battery in zero / wheres the battery and where can i get one?

[@mahut0]

Hi! Any idea where i can buy a power switch and button?

[@ludgermias7737]

I hold a Kurzweil 2500 R which wont play. Do yo u have a service manual for it?

[@garambandar]

Many thanks for these detailed videos. Could you please post the name of the generic LED display from ebay that you use. I was contemplating buying one of the $80 ones on ebay, then I heard you say don't buy the expensive one.

[@_oscillator]

Any 240x64 display with T6963 controller and LED backlight, for example: www.ebay.com/itm/Blue-240x64-Graphic-LCD-Module-Display-LCM-w-RA6963-T6963-Controller-w-Tutorial/301017373646?hash=item4616089bce:g:0E8AAOSwH8ta1vpK These displays using 5V for backlight, so there is no longer need for buzzing high voltage EL transformer anymore.

[@garambandar]

@@_oscillator Huge thanks for this information. I have a K2000 RS in the bottom part of my rack and I basically have to get down on the floor to read the display right now.

[@sagamusix]

It's interesting that even after replacing the EL strip, the display still looks rather dark in the video and the photo. On my K2500, the EL-backlit display is blindingly bright (I don't think it was ever replaced), about as bright as the modern LED replacement on my TG77.

[@bradthx]

My 2500 is the same way, super bright LCD and I also believe it is original. Kurzweil was using a newer and better LCD at that time, much more transmissive then these older displays.

[@10314347]

@@bradthx Correct. My K2600R also has the super bright display.

[@backlightsnew]

I believe the k2500 is a ccfl backlight, not el. It's more like a flourescent bulb, not the same as el technology.

[@ShallRemainUnknown]

@@backlightsnew Yes, the K2500 (and probably K2600 and K2661, too) use a CCFL compact fluorescent bulb for LCD backlight, unlike the EL electro-luminescent backlight panel in the K2000, and unlike the LED backlight in new aftermarket replacement LCDs sold today (like the one Brad used in this video). There's a YT vid of successfully using an long LED strip taken out of a totally different larger LCD monitor and adapting it to replace just the CCFL fluorescent bulb in a K2500. I'd hope you could still today just buy a replacement CCFL bulb, though.

[@sqmus]

Well I took a chance and went ahead and replaced the display in my K2500R. It didn't change anything. Still shows a blank glowing blue screen. Apparently the problem is somewhere else. Any suggestions?

[@backlightsnew]

Internal battery?

[@sqmus]

@@backlightsnew Thanks for the reply. The battery housing is indeed badly corroded, and when the display was still somewhat readable, it did show a low battery message. I found a site that sells what looks like to be that housing. It does need to be replaced, but do those batteries have any bearing on the display?

[@backlightsnew]

@@sqmus a non-working battery can cause the screen to be blank.

[@sqmus]

@@backlightsnew Thanks so much for your response. I wasted a lot of time and money replacing the screen. I'll replace the battery housing.

[@backlightsnew]

@@sqmus well I hope that's the answer. I just know that it is often the culprit when there's a brightly lit screen with no text.