Comments on: Hammond XB-2 Drawbar Decoding Diagnosis and Repair

By: Bob

Bob — Wed, 01 Nov 2017 18:22:50 +0000

Keith,

Have you worked or know about the protocol of the signaling waveforms between the keyboard and motherboard of the XB2 ?

I’m working on a interface for the manual keys board (MN50020PGV Gate Array IC) to use with a custom microcontroller.

CPU reads 7 data lines (KDB0..KDB6), also the KDSTB line.
CPU commands the MN50020PGV with 3 lines (KDTREQ, KDTACK and KRST).

By: Bob

Bob — Mon, 23 Oct 2017 02:45:01 +0000

I have also a XB-2. Pressing the keys makes quick random noises but nothing near from a musical note. Drawbars looks fine.

I have expertise on Digital Electronics; got the keyboard on a flea market and would like to revive it as a hobby. It has ver. 2.0 Roms.

At this time I’m building an microcontroller circuit that at first produces the same sound (without effects) from the classical B3 via MIDI. Information about the circuit is available on the Internet. I’m highly interested in to know well how the XB-2 generates the sound, so I can diagnose the actual failure.

Anyway, if someone has some XB-2 damaged main PCB I would like to buy for parts if cheap; the first try is to make the XB-2 to live.

If it works, I could copy the roms to share.

By: William Rode

William Rode — Fri, 21 Apr 2017 13:00:46 +0000

I need the main board or chip for my Xb3

Any Help?

By: William Rode

William Rode — Fri, 21 Apr 2017 12:58:29 +0000

In need of the main board for a Xb2, or the mother chip?

Any information to this part?

Thanks, Bill

By: Martin

Martin — Sun, 08 Jan 2017 12:04:17 +0000

Hi I wonder if you could help, I have a Hammond xb2 series 1 Rev the display comes up I did a system reset and that all worked I also tested the draw bars and the display recognises them and displays when I ajust them also key data is registering via the LEDs on pcbs.
I have no sound output at all even the headphone socket.
Could you please advise I am a TVs engineer so I am very ok electronics and test.
Kind regards.
Martin.

By: Mike

Mike — Sun, 11 Oct 2015 16:21:23 +0000

I’m having a similar issue with my XB2. For me, my drawbars just aren’t working at all. I’ve checked to see if a connector came loose or if a capacitor went bad and I don’t see a single a single thing wrong internally. Would a similar approach have to be taken to getting the drawbars working again?

By: Keith Neufeld

Keith Neufeld — Wed, 02 May 2012 15:20:19 +0000

Ted, I’m not familiar with the XB-5s and don’t have any suggestions on how to go about getting them repaired, sorry.

By: ted Andreadis

ted Andreadis — Mon, 23 Apr 2012 21:04:24 +0000

found your site and had a question.
I have 2 Hammond XB-5′s
the processors have gone out from what i’ve been told and i looking for someone to help me fix at least one of them.
Is there anything or anyone you can suggest.
the XB-5 was my main axe and I”m really bumming about this.
thanks
Ted Andreadis

By: dan

dan — Sun, 06 Mar 2011 20:19:22 +0000

good find!!