Korg BX-3 (Gen 1) Support
 This is Korg’s dual-manual version of the original Korg CX-3. It is literally two CX-3 organs in one case with the added feature of vibrato and chorus.
It is distinguishable from the second-generation BX-3 because its drawbars are to the left of each manual.
This keyboard is known by several aliases, analog BX-3, BX-3 v1, and BX-3.1.
Because the two manuals are independent of each other, there are a few things you can do with a BX-3 you cannot do on a Hammond B3.
For example, you can select percussion on the lower manual, and you can tune the manuals independent of each other.
Contents
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For most repair situations, our service is a mail-in repair of one or more circuit boards inside the equipment. This is to get around the prohibitively 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 versed in the basics of electronic repair, you can act as your own technician if you’re comfortable with that idea. At most, you may need a decent low-wattage soldering iron and a basic multimeter. 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 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 for 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.
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.
After we receive your main board and perform the initial evaluation, you’ll receive an estimate for what we believe it will take to repair the circuit boards. 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.
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, they 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.
- 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 boards as they are, or refund the shipping portion of your initial repair purchase to you and we retain the boards.
- 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 boards as they are, or refund the shipping portion of your initial repair purchase and we retain the boards. 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 boards 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, place them on a separate order.
Electrolytic Capacitor Replacement (Recap)
Parastream is pleased to offer complete aluminum electrolytic capacitor kits for the Korg BX-3. They include replacements for all aluminum electrolytic capacitors. Many organs have been plagued with leaking capacitors that eat PCB traces and cause all sorts of problems. Please note that these kits only include aluminum electrolytic capacitors as the other types such as mylar and polystyrene have proven to be very stable and have caused no problems to date.
Every electrolytic capacitor in these kits have a minimum endurance rating of 2,000 hours @85°C. For the non-EE, this translates to 11 years at 8 hours a day at normal temperatures under 40°C (100°F). This is what the capacitor manufacturers guarantee. In all probability you’ll do substantially better. The original specifications for the BX-3 was only 1,000 hours @ 85°C. Heat and humidity are the biggest killers of electrolytic capacitors, so avoid exposing your equipment (no matter who makes it) to temperature and humidity extremes. This is especially critical for storage. Due to the physics of aluminum electrolytic capacitors, the unpowered “shelf life” is far less than the powered “endurance.” Applying power to circuits containing these capacitors actually help to keep them healthy.
There is a kit for each circuit board. There is also a complete kit for the BX-3 which packages together the circuit board kits at a discount. Each circuit board 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 these capacitor kits. Things can get a bit tricky if you have to repair circuit board trace damage if the old capacitors leaked electrolyte. If you don’t feel comfortable removing the boards and replacing components, consider having us or a local qualified technician perform the work.
Services
Given the history of leaking electrolytic capacitors with this organ, and the organ’s age (in the 40s), we recommend replacing all the electrolytic capacitors with new ones unless they have been replaced within the past 20 years. You have two easy options from Parastream. You may purchase a capacitor kit for the whole organ and have your technician (or yourself) install it. Your second option is to have us do the recap for you. Purchase the circuit board repair services for each circuit board in the organ and include the capacitor replacement add-ons.
The tone generator circuit board is the large one behind the keyboard, and is the only one that can be removed without soldering wires. To remove it, pull off the connectors, remove the screws holding it down to the baseplate, and you should be able to pull it free.
Begin by purchasing the Korg KLM-244 Circuit Board Repair Service. This gets your circuit 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. If you want both circuit boards (upper and lower manuals), order two.
You may add additional services listed below, or you may order them later as instructed by our repair technician.
You may purchase parts listed below with or without the Korg KLM-244 Circuit Board Repair Service. If you have ordered the Korg KLM-244 Circuit Board Electrolytic Capacitor Replacement Service (07-01002100), do not order the Electrolytic Capacitor Kit, Korg KLM-244 Circuit Board (92-90000200), as the parts are included in the service. There is no service item for replacing an SM304A, SM305A, or SM305B; just add the parts to the order. If it is not currently in a socket, add Korg KLM-244 Circuit Board 40-pin Socket Installation (07-01002200). It is the same for the 50241 Top Octave Generator. If it is not currently in a socket, add Korg KLM-244 Circuit Board 16-pin Socket Installation (07-01002300). Parts specified as (Pulled) have been removed from socketed circuit boards and have been functionally tested in a Korg BX-3.
| Description | Part Number | Availability | Unit Price (USD) | Quantity | Ordering |
| IC, Siemens SM305A3 Organ Tone Generator, PDIP-40 (New Old Stock) | 39-00003051 | In stock | $90.00 | | |
| IC, Siemens SM305B Organ Tone Generator, PDIP-40 (New Old Stock) | 39-00003052 | In stock | $90.00 | | |
| IC, Siemens SM304A Keyboard Encoder, PDIP-40 (New Old Stock) | 39-00003041 | 4 in stock, more in 30 days | $90.00 | | |
| IC, Siemens SM304A Keyboard Encoder, PDIP-40 (Pulled) | 39-00103041 | 4 in stock | $65.00 | | |
| IC, Siemens SM305B Organ Tone Generator, PDIP-40 (Pulled) | 39-00103052 | 1 in stock | $65.00 | | |
| Electrolytic Capacitor Kit, Korg KLM-244 Circuit Board | 92-90000200 | 1 in stock, more in 10 days | $17.97 | | |
The control / mixer circuit board is mounted on the underside of the drawbar assembly and contains the tact switches and control potentiometers. To remove it, unmount the entire assembly containing the drawbars (this varies by organ model). There are 5 or 6 wires directly soldered to pads on the circuit board which must be desoldered. Carefully document where these wires go when you replace the circuit board later. Unplug the connectors and remove the mounting screws.
Begin by purchasing the Korg KLM-245 Circuit Board Repair Service. This gets your circuit 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. If you want both circuit boards (upper and lower manuals), order two.
You may add additional services listed below, or you may order them later as instructed by our repair technician.
You may purchase parts listed below with or without the Korg KLM-245 Circuit Board Repair Service. If you have ordered the Korg KLM-245 Circuit Board Electrolytic Capacitor Replacement Service (07-01002500), do not order the Electrolytic Capacitor Kit, Korg KLM-245 Circuit Board (92-90000301), as the parts are included in the service.
The power supply / rotary effect circuit board is mounted on the bottom plate of the organ on the left side near the back. To remove it, unmount the entire assembly containing the drawbars (this varies by organ model). There are several wires directly soldered to eyelets on the component side circuit board which must be desoldered. Carefully document where these wires go when you replace the circuit board later. Unplug the connectors and remove the mounting screws.
Begin by purchasing the Korg KLM-246 Circuit Board Repair Service. This gets your circuit 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.
You may add additional services listed below, or you may order them later as instructed by our repair technician.
You may purchase parts listed below with or without the Korg KLM-246 Circuit Board Repair Service. If you have ordered the Korg KLM-246 Circuit Board Electrolytic Capacitor Replacement Service (07-01002800), do not order the Electrolytic Capacitor Kit, Korg KLM-246 Circuit Board (92-90000401), as the parts are included in the service.
The chorus/vibrato circuit board is mounted on the center of back plate of the organ. To remove it, pull off the connectors, remove the screws holding it down to the baseplate, and you should be able to pull it free.
Begin by purchasing the Korg KLM-308 Circuit Board Repair Service. This gets your circuit 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.
You may add additional services listed below, or you may order them later as instructed by our repair technician.
You may purchase parts listed below with or without the Korg KLM-308 Circuit Board Repair Service. If you have ordered the Korg KLM-308 Circuit Board Electrolytic Capacitor Replacement Service (07-01003000), do not order the Electrolytic Capacitor Kit, Korg KLM-308 Circuit Board (92-90000101), as the parts are included in the service.
At this time, there are no upgrades available for the BX-3 (we’re working on some!).
We have nearly every part needed to repair a BX-3. For components related to a circuit board, look under the circuit board’s heading on this page. The following lists mostly mechanical parts for the CX-3.
| Description | Part Number | Availability | Unit Price (USD) | Quantity | Ordering |
| Korg KORG Mark (Small), Below Average | 60-01001105 | 1 in stock | $5.00 | | |
Korg BX-3/CX-3 Rear Panel [KOC-C30133] [64047100], Average | 60-01001224 | 1 in stock | $20.00 | | |
| Korg BX-3/CX-3 Sealed Cover for KLM-244, Average | 60-01001244 | 1 in stock | $4.00 | | |
| Korg BX-3/CX-3 Control Panel Shield, Average | 60-01001254 | 1 in stock | $2.00 | | |
| Korg BX-3/CX-3 Control Panel Mounting, Average | 60-01001264 | 2 in stock | $2.00 | | |
| Korg BX-3/CX-3 Lug Board [L-1205-6P], Average | 60-01001504 | 1 in stock | $5.00 | | |
| Korg BX-3/CX-3 Volume Potentiometer with Switch [EVC-BO5P18B14], Average | 60-01001514 | 1 in stock | $15.00 | | |
| Korg BX-3/CX-3 Phone Jack, Average | 60-01001564 | 2 in stock | $6.00 | | |
| Korg BX-3/CX-3 Phone Jack with cutoff, Average | 60-01001574 | 1 in stock | $7.00 | | |
| Korg Machine Screw, Pan Head, Phillips, M4, 8mm, Steel, Black Zinc [21-01560508], Very Good | 60-01001703 | 1 in stock | $2.00 | | |
| Korg Machine Screw, Pan Head, Phillips, M4, 30mm, Steel, Black Zinc [21-01560530], Very Good | 60-01001713 | 1 in stock | $2.50 | | |
| Korg Machine Screw, Pan Head, Phillips, M4, 30mm, Steel, Black Zinc [21-01560530], Below Average | 60-01001715 | 1 in stock | $1.50 | | |
| Korg Machine Screw, Pan Head Washer, Phillips, M3, 20mm, Steel, Black Zinc [21-70550520], Very Good | 60-01001723 | 1 in stock | $2.50 | | |
| Korg Machine Screw, Pan Head Washer, Phillips, M3, 20mm, Steel, Black Zinc [21-70550520], Average | 60-01001724 | 6 in stock | $2.00 | | |
| Korg Machine Screw, Pan Head Washer, Phillips, M3, 20mm, Steel, Black Zinc [21-70550520], Below Average | 60-01001725 | 1 in stock | $1.50 | | |
| Korg Machine Screw, Pan Head Washer, Phillips, M5, 30mm, Steel, Black Zinc [21-70570530], Average | 60-01001744 | 5 in stock | $3.00 | | |
| Korg Thread-cutting Sheet Metal Screw, Pan Head, Phillips, M3, 6mm, Steel, Black Zinc [21-69550506], Average | 60-01001754 | 2 in stock | $1.00 | | |
| Korg Flat Washer, M4, Steel, Black Zinc [21-20560500], Average | 60-01001764 | 2 in stock | $0.50 | | |
| Korg Flat Washer, M5, Steel, Black Zinc [21-20570500], Average | 60-01001774 | 2 in stock | $0.50 | | |
| Korg Flat Washer, M3, Clear Plastic [21-20556000], Average | 60-01001784 | In stock | $0.50 | | |
| Korg Machine Screw, Pan Head Crimped Washer, Phillips, M3, 6mm, Steel, Black Zinc [21-7155050], Average | 60-01001804 | 1 in stock | $1.50 | | |
| Korg BX-3/CX-3 Key, Note C, Average | 60-01003014 | 4 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note C, Poor | 60-01003016 | 1 in stock | $5.00 | | |
| Korg BX-3/CX-3 Key, Note D, Average | 60-01003024 | 4 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note E, Average | 60-01003034 | 3 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note F, Average | 60-01003044 | 4 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note G, Average | 60-01003054 | 4 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note A, Average | 60-01003064 | 5 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note B, Average | 60-01003074 | 5 in stock | $15.00 | | |
| Korg BX-3/CX-3 Key, Note CC, Average | 60-01003084 | 1 in stock | $20.00 | | |
| Korg BX-3/CX-3 Key, Black, Average | 60-01003094 | In stock | $10.00 | | |
| Korg BX-3/CX-3 Key Spring, Average | 60-01003104 | In stock | $0.50 | | |
| Korg BX-3/CX-3 Key Stop (Rubber), Average | 60-01003114 | In stock | $3.50 | | |
| Korg BX-3/CX-3 Key Contact Panel, Average | 60-01003184 | In stock | $15.00 | | |
| Korg BX-3/CX-3 Drawbar Holder [KOC-C30134] [64028600], Average | 60-01003304 | 1 in stock | $15.00 | | |
| Korg BX-3/CX-3 Drawbar Knob, 5⅓' [62002000], Average | 60-01003314 | 1 in stock | $6.00 | | |
| Korg BX-3/CX-3 Drawbar Knob, 1⅓' [62002300], Average | 60-01003344 | 1 in stock | $6.00 | | |
| Korg BX-3/CX-3 Drawbar Knob, 8' [62002500], Below Average | 60-01003365 | 1 in stock | $4.00 | | |
| Korg Tact Switch Hinged Bracket with LED, Average | 60-01003504 | In stock | $7.50 | | |
| Korg Tact Switch Knob, Dark Brown [DIC 504] [62001900], Average | 60-01003514 | 4 in stock | $5.00 | | |
| Korg Tact Switch Knob, Ivory [DIC 547] [62002900], Average | 60-01003524 | 4 in stock | $5.00 | | |
| Korg Tact Switch Mask [KOC-F40152] [55002800], Average | 60-01003534 | 2 in stock | $2.00 | | |
| Korg 10ø Knob [ø10 X-1070] [62007400], Average | 60-01003544 | 6 in stock | $5.00 | | |
| Korg Lever Switch Mask [X-0600] [550000100], Average | 60-01003554 | 6 in stock | $1.00 | | |
| Korg KLM-245 Tune Potentiometer [EVH-LOAS20B14], Average | 60-01003564 | 1 in stock | $10.00 | | |
| Korg KLM-245 Overdrive Potentiometer [EVH-LOAS20B16], Average | 60-01003574 | 1 in stock | $10.00 | | |
| Korg KLM-245 Bass / Treble Potentiometer [EVH-LOAS20B15], Average | 60-01003584 | 2 in stock | $10.00 | | |
| Korg KLM-245 Percussion Decay Potentiometer [EVH-LOAS20A55], Average | 60-01003594 | 1 in stock | $10.00 | | |
| Korg KLM-245 Percussion Volume Potentiometer [EVH-LOAS20A14], Average | 60-01003604 | 1 in stock | $10.00 | | |
| Korg NH Header, Bottom Entry 3 Pin [24-90300300], Average | 60-01003614 | 1 in stock | $2.00 | | |
| Korg NH Header, Bottom Entry 4 Pin [24-90300400], Average | 60-01003624 | 1 in stock | $2.00 | | |
| Korg NH Header, Bottom Entry 7 Pin [24-90300700], Average | 60-01003634 | 1 in stock | $2.00 | | |
| Korg NH Header, Bottom Entry 9 Pin [24-90300900], Average | 60-01003644 | 1 in stock | $2.50 | | |
| Korg NH Header, Bottom Entry 10 Pin [24-90301000], Average | 60-01003654 | 1 in stock | $2.50 | | |
| Korg 2SC945 Matched Pair, Average | 60-01003664 | 1 in stock | $5.00 | | |
| Korg KLM-244 B, Main Circuit Board with Sockets [34012804], Fully Restored, Average | 60-01009014 | 1 in stock | $350.00 | | |
| Korg KLM-246 C, R.E. Circuit Board [34013003], Fully Restored, Average | 60-01009084 | 1 in stock | $125.00 | | |
| Korg BX-3/CX-3 Drawbar Wiring Harness, Average | 60-01009204 | 1 in stock | $10.00 | | |
| Thread-cutting Sheet Metal Screw, Pan Head, Phillips, M3, 10mm, Steel, Zinc Alloy | 21-69550410 | 5 in stock | $0.25 | | |
| Machine Screw, Pan Head Crimped Washer, Phillips, M3, 6mm, Steel, Zinc Alloy | 21-71550406 | In stock | $0.35 | | |
Important information for Customers outside the US:
If you choose to ship via International Economy,
Parastream can only guarantee that your shipment arrives at the point of entry into your country.
The tracking number may not provide status once it reaches your country.
Parastream will not be able to offer any assistance in tracking your shipment once it reaches your country.
If you require complete end-to-end tracking and delivery guarantees, you should choose Standard International.
More information...
We recently had a customer post a detailed step-by-step procedure for replacing
keys in a Korg BX-3: https://www.flickr.com/photos/cavemusic/5442306025/in/set-72157626041701006.
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.
Visit our Korg BX-3/CX-3 Gen 1 Troubleshooting page if you would like to take a crack at repairing your BX-3.
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Manuals
IC Datasheets
Theory of Operation
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