Korg BX-3 (Gen 2) Support

This is Korg’s second generation of the dual-manual BX-3 organ. Unlike its predecessor, this BX-3 is digital and has far more capabilities. It is distinguishable from the first-generation BX-3 because its drawbars are across the top of the upper manual. This keyboard is known by several aliases, digital BX-3, BX-3 v2, and BX-3.2.

This page covers Korg BX-3 repair and Korg BX-3 parts.

• Repair Services
• Parts
• Videos
• DYI Resources

Visit our Facebook group for announcements, discussions, and more information about supporting the Korg BX-3.

We put a lot of time into creating, gathering, and organizing the information in this page. If you found any of this to be useful to you, especially if it helped you to make or save money, please  to help us continue making content like this available.

Repair Services

For most repair situations, our service is a mail-in repair of one or more circuit boards inside the organ. This is to get around the very expensive round-trip shipping that would otherwise be required. Typically, we work with your local technician. Sometimes, all your technician needs is a little direction from us. In other cases, they can remove the circuit board(s), send them to us, and replace them once they are returned from us. If you are comfortable opening up the organ, you can act as your own technician. Check out our videos to see how easy it is to send us the main board and put it back in when we return it to you. If you would like for us to service the whole organ, you will need to arrange it with one of our service technicians using the Support request form.

The following services are for individual circuit boards inside the BX-3, and include return shipping. If your organ doesn’t power on at all and has a blank display, it’s probably the KLM-2090 (Power Supply). Most other problems are usually in the KLM-2168 (Main Board). If you’re not certain what’s wrong, use the Support request form and we will help you. The most common approach is to purchase a circuit board repair service for each of the circuit boards you’d like us to repair. These services will get your circuit boards into our shop and then back to you when they are diagnosed or repaired. This includes the initial checkout, diagnostic, and report, as well as final testing of any repairs.

Once you make your service purchases, carefully pack the circuit board(s) and send the box to the address in the Contact Us page. Check the videos for help with disassembly and packing. When we receive your shipping box, you will receive an email with an estimated starting date for your job. Repair services are performed in the order in which your shipping box arrives.

NOTE: If we do not receive your shipping box with 30 days, we will attempt to remind you to please send in your circuit board. If we do not receive it in 90 days, we will issue a refund for the purchase.

After we receive your circuit board and perform the initial evaluation, you’ll receive an estimate for what we believe it will take to repair it. We work hard to catch every problem in the estimate, and we are successful in the vast majority of cases. The main board is a very complex circuit containing six microprocessors. Because of this complexity, there may be other problems hiding behind what we found in the initial estimate.

NOTE: The estimate is good for 30 calendar days. If you do not respond within 30 days, we will make multiple attempts to contact you through all means you disclose to us (email, phone, etc.). If we still cannot reach you after an additional 15 calendar days, we will return your circuit boards to you.

If you choose to proceed, go to our website and order the services specified in the estimate. When we receive the order and payment, we will place your repair order in the queue for repair. Once the repairs have been performed and have passed all tests, the circuit board will be carefully packed and shipped back to you. Although exceedingly rare, the post-repair testing may find additional problems that need to be addressed. This situation can go one of two ways.

1. Hopefully, we can identify what we believe will fix the circuit boards and give you a new estimate. If you decide to proceed with another round, order the indicated services. If you decide not to invest further in the organ, we understand. We can either return your circuit board as it is, or refund the shipping portion of your initial repair purchase to you and we retain the boards
2. Although this has never happened so far, we could find a problem so severe that it becomes impossible for us to do a proper repair. In this case, we can either return your circuit board as it is, or refund the shipping portion of your initial repair purchase and we retain the board. We would prefer to keep our perfect repair record if it is at all possible!

If you are purchasing parts or other items along with repair services, they will be shipped in the same box with the circuit board when the repair services are complete. This is done to minimize shipping charges. If you would like the parts to be shipped to you separately, please place them on a separate order.

These are the services we offer:

• KLM-2168 (Main Board)
• KLM-2090 (Power Supply)
• Display Module

KLM-2168 (Main Board)

Please note that we do not have replacement KLM-2168 main boards for sale. Korg’s inventory of these boards dried up by 2010 and they are nowhere to be found. You must have a previously working KLM-2168 for us to be able to help you.

Begin by purchasing the Korg KLM-2168 Circuit Board Repair. This gets your main board into our shop and then back to you when it is repaired. This includes the initial checkout and report, as well as final testing of any repairs.

After we receive your main board and perform the initial evaluation, you’ll receive an estimate for any additional services needed for repair. In most cases, the estimate will be one or more of the additional services listed here; otherwise, it will be a fixed cost for parts and labor. We work hard to catch every problem in the estimate, and we are successful in the vast majority of cases. Due to the complex nature of the circuitry in the organ, there may be other problems hiding behind what we found in the initial estimate.

IMPORTANT: Please read the Repair Services section above and make sure you fully understand show the repair services work before placing an order. If you have any questions, use the Support request form and we will do our best to answer them.

FAQ

Will my saved programs get wiped out?

You should assume so. We will set the repaired main board to factory settings when the repairs require it. You should document any programs you want to save before sending us your main board.

KLM-2090 (Power Supply)

Begin by purchasing the Korg KLM-2090 Circuit Board Repair. This gets your power supply into our shop and back to you when it is repaired. This includes the initial checkout and report, as well as final testing of any repairs.

After we receive your power supply and perform the initial evaluation, you’ll receive an estimate for any additional items needed for repair. In most cases, the estimate will be one or more of the additional services listed here; otherwise, it will be a fixed cost for parts and labor.

IMPORTANT: Please read the Repair Services section above and make sure you fully understand how the repair services work before placing an order. If you have any questions, use the Support request form and we will do our best to answer them.

Display Module

Replaces the fuse on the display module. This is the only repair we can do on the vacuum fluorescent display module. This gets your display module into our shop and then back to you when it is repaired.

Services not described here may be available on an add-on or time and materials basis. Use the Support request form to inquire.

Parts

You may purchase many replacement parts for your BX-3. At this time, we do not have mechanical parts such as knobs and keys.

KLM-2090 (Power Supply) Electrolytic Capacitor Kit

This kit contains all 8 aluminum electrolytic capacitors for the power supply. The kit comes with a color-coded circuit board layout and color-coded bags of capacitors. If you’re an average electronics DYIer, you can install this kit. Every capacitor meets or exceeds the original factory specifications.

We do not recommend replacing the KLM-2090 electrolytic capacitors unless you know there is a problem with one or more of them. The KLM-2090 is built with long life capacitors, rated from 3,000 to 6,000 hours at 105°C. For the layperson, this translates to 60 to 120 years running 8 hours a day at temperatures under 45°C (113°F). Frankly, other components are likely to fail first. Aside from failures or storage of the organ for prolonged periods at high temperatures, these capacitors should not wear out.

KLM-2168 Phone Jack Kit

Contains five replacement ¼" (6.35mm) jacks for the KLM-2168 board. If you’re an average electronics DYIer, you can install this kit. Here’s an interesting piece of trivia about these jacks – in 2016, the manufacturer switched from silver plating to tin plating to reduce costs. By the way, manufacturers of similar products had already done this. The silver oxidation is probably why so many phone jacks look so bad. We recommend replacing the jacks as a last resort after all other rehabilitation efforts such as cleaning have failed.

Korg BX-3/CX-3 Firmware Flash Chips

Contains two flash chips programmed with the latest available firmware from Korg. When you place an order, the chips are dried per J-STD-033B to avoid moisture-related failures during reflow and then programmed to maximize their data retention. This is an advanced skill level job, requiring desoldering and replacing two 44-pin SOIC parts. When we perform this repair, we use a SOIC-44 hot air station nozzle.

Miscellaneous Repair Parts

Many repair parts that are unusual or hard to find are listed here. If you can’t find what you need, ask us!

All the above parts are for the KLM-2168 (main board) except the fuse, which is for the vacuum fluorescent display board.

Videos

• s01e001: How to remove the power supply from a Korg CX-3 Gen 2 (the process is very similar on a BX-3 Gen 2)
• s01e002: How to remove the main board from a Korg CX-3 Gen 2 (the process is very similar on a BX-3 Gen 2)
• s01e004: How to replace the power supply from a Korg CX 3 Gen 2 (the process is very similar on a BX-3 Gen 2)
• s01e005: How to replace the main board from a Korg CX-3 Gen 2 (the process is very similar on a BX-3 Gen 2)

Check out our YouTube channel for more videos!

DYI Resources

We put a lot of time into creating, gathering, and organizing the information in this page. If you found any of this to be useful to you, especially if it helped you to make or save money, please  to help us continue making content like this available.

DYI Repairs

If you have good soldering and desoldering tools and skills, you may want to consider doing some repairs yourself and save labor cost and time.

Replacing Tact Switches

Are some of the panel buttons not working reliably? Do you have to press them repeatedly to get them to work? You might want to consider replacing the tact switches. There are 33 of them in the BX-3. These tact switches are susceptible to dust, smoke, and other contaminants. We used to offer services for the tact switches, but it didn’t sell well. We suspect that our reference organ was subjected to one or more liquid spill episodes, causing them to be unreliable. Most organs do not seem to have this problem.

If you want to replace some of the tact switches on your organ, we have good and bad news. The good news is that we have the exact part number for the switch used by Korg, and even an upgraded part which we used to offer that has 10 times the rated lifespan. The bad news is that the manufacturer discontinued the parts in 2020, and they may be difficult to find. The original switch is a Panasonic EVQ11A09K, and the upgraded part is EVQ11D09K. They are identical in all mechanical and electrical specs except the 'D09K has 10 times the rated lifespan. There are other variants with different actuation forces, but are otherwise compatible.

While this will take a while to disassemble the organ, replace the switches, and reassemble the organ, it will make it operate like new. To prolong the life of your new switches, we recommend keeping the organ under a dust cover when not in use.

Replacing Phone Jacks

The ¼-inch phone jacks can get corroded or worn out. If you are experiencing scratchy or intermittent operation plugging in cords into the phone jacks, try cleaning them with DeoxIt first. DO NOT Spray directly into the jacks! Instead, saturate a swab and insert it into the jack. Move the swab in and out a few times and try to reach toward the top of the jacks where the contacts are. If this does not fix the problem, the jacks must be replaced.

You may purchase the jacks from us here, or from another supplier. This operation will require a slightly higher skill level than replacing the tact switches, as the printed circuit board is two-sided. You may find some helpful videos here.

Replacing the Firmware Chips

While this is not a common repair, replacing the firmware chips may be necessary if you have determined that the firmware has degraded due to “bit rot” or other problems preventing the organ from booting.

You may purchase the set of firmware chips from us here. The firmware chips are programmed after you order them and have not been sitting on a shelf for years. This is an advanced skill level job, requiring desoldering and replacing two 44-pin SOIC parts. When we perform this repair, we use a special nozzle for SOIC-44 with our hot air station to remove the old chips.

Manuals

• Korg BX-3 (Gen 2) Owner's Manual
• Korg BX-3 (Gen 2) Service Manual

IC Datasheets

• NEC H8S-2357 Group Hardware Manual (MPU used in KLM-2168)
• NEC H8S-2000, 2600 Series Software Manual (MPU used in KLM-2168)
• Motorola DSP56362 (TG DSP used in KLM-2168)
• EliteMT M11B416256A, EtronTech Em614163A, Mosel V53C16256H.pdf, tmTech T224162B.pdf (DRAM used in KLM-2168)
• Fujitsu MBM29F400BC (Flash used in KLM-2168)
• Burr-Brown PCM1716 (D/A converter used in KLM-2168)

The Motorola DSP56362 is used as a tone generator and keying matrix processor in the KLM-2168. This chip is no longer in production. Because of its early reliability problems, we have decided to publish some of our research into this part here. This article may help you find your own parts on what we call the “EOL Market,” and how to avoid risky parts.

The TMS57070 chip (used in the KLM-2168) was a rather short-lived DSP from Texas Instruments that ran from 1995 through 2000. The BX-3 uses two of these chips to create the vibrato/chorus, rotary effect (Leslie), reverb, and mixes in the percussion signal from the tone generator post-vibrato/chorus. There is no official information about this DSP from Texas Instruments, but a very clever fellow has taken on the project of reverse-engineering the part. You can see his work at GitHub - Prehistoricman/TMS57070: Tools & docs for the TI DSP TMS57070 including disassembler.

General Information

You may access useful information for debugging and determining what version of the firmware your organ has. Refer to the following table as a guide, and hold down the indicated buttons while switching on the power. Be patient. You have to hold the buttons down until the desired information displays.

PROGRAM 1 and PROGRAM 8

Displays the loader firmware version. It is normally displays Ipl V2.00   000422AB. This is the original loader version and never changed throughout the production of the BX-3.

PROGRAM 2 and PROGRAM 7

Perform a factory reset. Displays Load Factory Data?  , Press the WRITE/ENTER button to completely refresh the unit to factory condition.

PROGRAM 4 and PROGRAM 6

Enter the Test Mode. See Test Mode for details.

DISPLAY

Displays the master and subsystem CPU firmware versions. The one and only BX-3 versions are Main 2.01 Sub 1.00  .

Test Mode

The test mode begins by testing the internal components of the organ, and then moving into interactive tests of the keys, buttons, and lights. If you have a MIDI cable, connect it from the IN jack to the OUT jack for the MIDI loop test. If you don’t have a cable, you can skip the test when it reports an error.

During test mode, use the following percussion buttons to navigate:

The following table shows the test steps.