Problems and Fixes for the Kurzweil K1000 and K1200 *

Hard Reset

Caution, a hard reset erases all of the user created patches and other setup changes in the RAM.  Use one of the software programs or a sysex dump to save you work before you do a hard reset. On older Expanders, press and hold YES and NO buttons as you turn on the power. On the 1200 Series and some keyboards, hold A and B and turn on the power.  Select some program other than 001 before you do the reset. You will know a reset was done if program 001 is selected after the power on.

Test Mode

This runs various diagnostices. On older Expanders, press and hold Program and Parameter buttons together and turn on the power. On the 1200 series and some keyboards, press C and Play/Edit and turn on the power. It takes a minute so be patient. A menu appears that you can navigate and test the RAM, ROM, OS, LCD, Buttons, and Battery. Read the service manual for details. For instance the battery test requires a special sequence. It can go over the various tests repeatedly and some tests are not fast. The ROM test takes 4 minutes. Midi Loop test typically fails and should be ignored.

ROM 33 I saw the following error message: er 4 lset rom -33 reported by Daniel in Argentina
EXCKSM 49c4
OBCKSM CD1f

This message was related to improper motherboard preparation. Checksum is the total number of 1's and 0's on the chip in question. This number is known and embedded in the OS. The OS has come up with a wrong number during selfcheck. This could be 1) defective chip OR 2) the OS is not able to check the chip (motherboard) Checksums are printed on original OS chips, you can see them on the sticker. 

Power Problems

General: Many users report that the P1 connector on the power supply board is the root of many startup and other problems. (Especially the HX modules) (See also below)

Common and running problems. Everyone reports that the P1 on the bottom side of the power supply board gets "cold" and fails to make a good connection. This is known as a 'cold solder'. The solder is grey and dull rather than shiny and bright. With a soldering gun reheat and bond the solder. Don't touch or move the board while cooling (the cause of the cold solder). This may have been a production problem. Of the 11 modules I have, 3 have had P1 problems. This problem is sometimes so elusive that it appears to be any other problem. If something doesn't get better quickly I would resolder the P1 connector just because you have it open. You may be pleasantly surprised! 

User report

Just wanted to update you on my progress. I tried all the suggestions the group gave me, reseated the chips, checked
the power supply. I found a cold solder joint on the 22000uf 16vdc electrolytic capacitor on the power supply board,
the big one. Boots up fine, and now I can use it. It's been a good week. Thanks for all your help, Robert. 
P1 connector

Won't start or No Sound

Plugged in? fuse on the power supply board? Most do not have a fuse. A few early modules did. Power to P1 connector? 

Startup click? bootup sequence has an audible click about 3 seconds after the ON button is pressed. If no click the Relay on the mother board is stuck. Open the unit and tap gently on the relay. On the Motherboard is printed # Q 005 a box labeled "zettler", over near the audio outs. The relay connects the audio to the output jacks.
Tap on it gently. It's a plunger that moves and it gets stuck in the mud. If it doesn't click after tapping, tap harder.  A relay is a standard electronic part.

Relay part no. Here's the relay that I used for repair of my K1000: Aromat/Panasonic DS2Y-S-DC12V Digi-Key item # 255-1079-ND. Cost: approx. $2.65 (+S&H) -Dallas (thanks Dallas!)

Cyclic clicking? The P1 connector needs to be resoldered. Remove the powersupply board and solder it from the bottom side. Power supply manufacturing issue: board with the copper traces for the 5VDC secondary go bad. The surface area of the copper traces is too small to handle the current for 5VDC, they go bad and the 5VDC goes out of regulation. One user reports all 4 of his did this. 

Keyboard Story

For an interesting tale of the wiring under the Keyboard. This is a rare problem. see dead-keys for more information.

LCD light

They grow dimmer with age and finally go out. The original is a Seiko M1632, widely available for less than $10. Seiko Model M1632, tech sheets and data can be found at the website. http://www.eio.com/m1632ap.htm OR Densitron LM4262 depth 14 cm Densitron LM2162 depth 10 cm http://www.densitron.com/displays/products/?o=1&cat=1&id=1 Installation instructions can be found here backlight-fix.  This is a difficult change because of space requirements. Telesisgear.com http://backlights.telesisgear.com <http://backlights.telesisgear.com/> .
They are friendly, reasonably priced, and excellent instructions. 

Weird behaviour

Sometime pins in sockets get oxidized. Pull each chip carefully and clean carefully. Use standard chip puller. Digital noise that appears random, AFTER an upgrade? David G has discovered that some of the boards had JP05 hanging in the air and wasn't connected to anything. Instructions/info on upgrades page and chip data page.

Here is a typical fixit story related to oxidized pins/sockets - from June 2008
(Names removed by webmaster)
User:  My K-1000 is 15 yrs old and after a cross ocean voyage and an 8-year stint in bone dry but roasting temps in a garage in a flight case, it makes weird sounds when more than 1 key is played. Some sort of off pitch reverberation randomly triggers. Neither the "reset" nor the "test" functions work, according to the procedure mentioned here. Nothing happens. Although I just bought a chip puller and have an array of small flat screw drivers, I'm really scared to start pulling chips off to clean oxidation that is not readily apparent to me. I'm scared the tiny legs will either break off or not insert back in. Also, I don't want to pull off something that's not meant to come off. Any advice from someone who's done the oxidation removal or has a different repair in mind to suggest? I'm grateful for any insight to help me avoid ruining something I love.
Helper1: Pull off the OS chips and clean the legs. The OS chips will permit you to self test. Don't be afraid, pull the ones in sockets. We can replace any chip that's in a socket but for now remove only the U21-22-31-32 and clean them. It's got to be one of those chips or the P1 connector which is all on the website.
User: Found the U21 and U32 chips immediately and though there was no visible oxidation I pulled and cleaned them with alcohol.  Spent a couple of hours going through the schematics to find the U22, U31 chips without success. In any case, before getting set up for the P1 routine I decided to power up and behold, just like new. No noisy artifacts. All fixed!  Thanks!
Helper1: That's GREAT! You might think about running the self test and it will tell you if any other chips are needing a little work. The proceedure is in the manual, a bunch of button pushes an wait while it tests everything.
Helper2: You couldn't find the other 2 chips? The 4 OS chips are in a square next to each other. Don't look at the schematics. Look at the board. I have my doubts about the alcohol cleaning. You cannot remove oxidation with alcohol. The pulling and putting them back probably did the trick.
Note from webmaster: The K1000 Keyboard has only two OS/Setup Chips. U22 and U31 do not exist in the Keyboards.
Followup: Here is how to clean contacts on the chips. Carefully clean the pin legs on the chips. Best practice is to wipe them gently with an eraser. If your comfortable with a little vinegar (acid bath) OK but just paint it on the legs with an artists brush then paint the legs with water and dry. Other things that work are brillo abbrassives (NOT the steel wool pads) but the kind that come on the back side of a sponge in a green layer. With a BRAND NEW brillo abrassive gentley wipe the pins without bending in the direction away from the tips. It should take about 20 wipes on each side and gentley. We can replace the chip but it's gonna cost ya about $8-12 depending on chip prices.

Sounds seem like random waves?

Electrical connection on a chip is lost. During insertion of a chip you bent, broke or failed to insert a pin. A ROM chip is in the wrong socket. Oxidation

No sound

This is most often caused by a faulty audio output relay - a relay that connects the audio to the two output jacks on the back of the expander or keyboard. If the relay gets stuck or fails, no sound will be heard at the output jacks. Sound will be heard thru the headphone jacks on the keyboards even if the relay fails.  Solution is to tap on the relay, take it apart and clean it, or purchase a new one.  (See "Wont Start" above) 
After an upgrade: ROM chip is HOT? You inserted it backwards.  Check audio board area for burn marks, audio boards seldom fail. If you insert a chip backwards you can kill your entire module. BE CAREFULL. 

Boot up freezes

Display shows: DATA PC 42010080 / 80037C 42010080 This is what was displayed when 2 RAM chips were added. On power up the screen froze and displayed this, and the instrument would not respond to any commands. This was an experiment by Andrea Toni in the Netherlands to increase the amount of memory. The Kurzweil was smarter than Andrea. 

Screen freezes: generally this means the OS can't complete it's boot sequence and any work that you just did needs to be carefully reviewed.

More from another user:  "db, are you aware of an issue with the power supply board with the copper traces for the 5VDC secondary going bad?  The surface area of the copper traces is too small to handle the current for 5VDC, they go bad and the 5VDC goes out of regulation.  I own four 1000 series boxes, had to fix that problem for all of them."  -analogdiehard 

Will not save programs/patches setups

This could be a dead backup battery. The batteries are designed to last 5 to 10 years. Some last less, some longer. You can replace the battery but be very very careful. They are soldered into the circuit boards. You can not apply heat for more than a few seconds and if you apply too much heat the battery may explode or be ruined at the least. Do not attempt this if you are not experienced soldering to batteries. Best to get an experienced technition to do the spot weld type soldering to to it right!

Known repair guys

Advanced Musical Electronics in LA, USA
Synth Service Centre, London England
http://www.synthservice.com.
if you know any more repair centers email me from the contact page.

Parts are here: 

http://www.dgaudiorepair.com/vintage.htm They have a list of all sorts of stuff that changes.

The P1 Connector can cause almost any problem.  Below is the way it looks when it's bad.  You may need a magnifying glass to see the fracture locations.  This one required considerable magnification to see it.  

This is on the bottom of the power supply board which must be removed.  It's probably smart to resolder this connection if it hasn't been done since manufacture date.  

Below is what it looks like when it's resoldered.  This is a common problem.

Thanks to user group member for the great pictures!  

* From the ex-Alzerom site with approval of David B.  (Some mods made by web master)