Ensoniq ASR-10 Rack Sampler and SCSI Repair

Ensoniq ASR-10 Rack Sampler
Ensoniq ASR-10 Rack Sampler

Last weekend I picked up a used Ensoniq ASR-10 Rack Sampler in the used music shop here in Nagano-city, JAPAN. It was pretty cheap mainly because the sales clerk couldn’t provide an OS disk, manual, or any other accessory. Thus he couldn’t properly test the product, so he basically sold it as junk and practically gave it away.

I bought the sampler because I’ve always been a big fan of the ASR-10 keyboard, but never found one for a reasonable price in Japan. Although I would have probably preferred the keyboard version, the rack works out well because I feel I already have too many synths and samplers as is. So, this rack shouldn’t take up much extra space.

The condition of the ASR-10 rack is excellent. In fact, inside it was pretty much spotless with no visible signs of wear or dirt. The outside had no scratches, but it was missing the rack ears. I powered up the ASR-10 rack after acquiring an OS disk copy and it booted just fine. I noticed that the OS was 3.53 and the firmware was 1.50. Note I had to create the OS disk using my Windows 98 laptop in DOS using special Ensoniq software.

The Ensoniq ASR-10 rack works fantastic in all areas with the exception of the SCSI interface. Only ONCE, could I successfully boot the ASR-10 rack and get the “searching for SCSI devices” message upon startup. At that time I had my trusty blue Iomega 100MB zip drive with disk inside ready to go. I was able to get to the Format SCSI Drive screen. I proceeded through all the steps even getting past the Interleave screen. When it hit formatting, it just blinked for a second and then reverted to “disconnected SCSI device”. I have since been unable to get back to the “Searching for SCSI Devices” screen during the boot stage. Frustrating! Note I don’t believe I got a light blink which indicates the ASR-10 detected the Zip drive.

I completely took apart the ASR-10 Rack and checked all of the fuses which tested just fine for continuity. I then pulled and reseated all of the cabling which included cleaning. Everything looks amazing inside, but unfortunately, the SCSI simply doesn’t work right now which has left me unsure about what to do next.

Other than the SCSI problem, the Ensoniq ASR-10 Rack works perfectly and it’s really easy to sample and jam with right away. Currently I have 16MB of ram on board, but it will be a chore loading and saving all that data without the SCSI working properly should I choose to utilize it all. The floppy drive works great and I also have a backup HxC Floppy Emulator that works too should I require another drive.

Note that I have tested the ASR-10 rack with a working Iomega 100MB SCSI zip drive, Olympus SCSI MO drive, 2GB SCSI hard disk, and an old SCSI CD Rom drive that all work with all of my old samplers. I don’t believe I have an SCSI cable, drive, or media problem. The issue resides somewhere inside the Ensoniq ASR-10 rack.

No doubt I’ll be making great use of the ASR-10 rack as it’s extremely easy to use and sounds amazing. It’s so much easier to use than my old Akai gear in fact. I just wish I could get the SCSI to snap out of it and start working. I’ll update this article should I find a solution. Stay tuned!

NOTE #1: A few times I got the infamous ASR-10 “Error 129 reboot” message. To fix this you need a 100% working OS floppy disk. There are some bad OS images floating around including those on sites where everybody gets them. After using a quality floppy disk and image, I was able to completely eliminate the 129 reboot message. I haven’t had it all week, not once. I have about 3-4 bad image disks from various sources and they literally flood my ASR-10 with 129 reboot messages. The error is a software one, which means you need a decent software image.

20 thoughts on “Ensoniq ASR-10 Rack Sampler and SCSI Repair

  1. Hi Jim!
    I had similar problems with an Akai S1000. On this sampler it showed that a fuse is near the SCSI connector that deliver 5V to the SCSI connector. If you connect the SCSI device when the sampler is powered on it could happen that this fuse could be blown. Afterwards no reaction on the SCSI interface any more. The solution to prevent from fuse replacing every time you make a hotplug was: Install a polyfuse instead of the fuse. This gives safety in case if wrong connections and heals automatically after fault condition removed.
    Maybe the ASR10 also has a little fuse (sometimes in wired resistor look!) and so the same problem…

    1. Thanks for the reply. I just discovered Tom’s blog site. I’ll send him a note and see what he says. I believe someone on there asked the same question a while ago, but he hasn’t replied yet. I’ll keep you posted. Thanks again.

  2. N B

    Hey Jim,

    Things I would try:

    A different copy of the os and a new floppy disc.

    Replace memory chips.

    Pull scsi connector if possible and re-seat.

    Re-solder scsi connector solder points and check for continuity.

    Replace or re-flash if possible, the firmware chip(s).

    If one of those doesn’t fix it, then it’s most likely a deeper issue.

    I hope this helps.

    Best, Nicholas

    1. Thanks Nicholas! I’ve noticed that every time I create a new OS disk things change, so I’ll try that again. Also, re-soldering the SCSI connector solder points and checking for continuity sounds like a great plan too. I’ll update shortly. Thanks again.

  3. I contacted Tom Virostek from http://www.straylightengineering.com and he gave me a really quick reply.

    His advice was to replace the 26 pin SCSI cable running from the SCSI board to the Main ASR-10 board. So today I put in an order for some new cabling and connectors.

    Interestingly, I also blew two 4.0 Amp fuses today while experimenting with some different cables which I knew were not quite up to specs. The fuses were fine yesterday, BUT, today ( F3 and F4 fuses ) just couldn’t handle my experimentation. Perhaps replacing the fuses will help things as they are used if correct by the SCSI board among other areas of the ASR-10.

    So, now I’m in wait mode until I receive the supplies needed by mail. The crappy thing about where I’m at in Japan, is that you can’t just go down the street and buy the necessary parts. While Japan is a huge electronics place, it really sucks with regards to finding parts. Japan is no way like Taiwan or China where you can find this stuff anywhere and at anytime…laugh.

    1. Note that to replace F3 and F4 fuses, I bought 20mm 4A fast blow 250V fuses. I couldn’t find any 20mm 4A fast blow 125V fuses anywhere around me. I read that this would be ok HOPEFULLY!

  4. I also made copies of the firmware 1.50 today and saved them to my computer. I plan to re-flash a backup copy here shortly in the event that might be necessary.

    My Ensoniq ASR-10 Rack OS firmware is labeled as follows:

    ASR 1.50B
    65E0 UPPER

    ASR 1.50B
    648C LOWER

  5. jim it is known that the asr10 does not like the zipdrive scsi cable try a different cable

    also the 26pin idc to 25dsub connector check that pin one is on connection where the stripe is as if its been put in backwards it would not work

    but also check continuity via the 26pin idc and the 25 dsub connector

  6. there is no fuse on the scsi board of the asr10 as it does not provide termpower

    on the akai the termpower connection has a fuse what happens is the external device also provides termpower and the fuse blows because of to much ampage load
    or someone has tried to remove the connector from the scsi drive while powered on causing a short you can fit resetable fuses on these but the ensoniqs dont suffer from this as they dont provide it

    the problem with this is that on the eps/eps16+ the scsi board also does not provide termpower but needs to receive it for the scsi interface to work as the zip drives dont provide it the eps wont work with zip drives with out modification which is a simple 5v to diode to pin 25 of the dsub connector

  7. Update:

    I replaced all of the cables for the SCSI board and checked for continuity on the 26pin idc to 25dsub connector. Everything looks good. I also replaced all of the fuses although I probably didn’t need to do that as everything seemed to be working.

    I still don’t get a SCSI detected or searching for SCSI devices message when powering up the ASR10.

    So, for now I’ll likely just use the floppy drive and work from that. I’ll keep an eye out for a replacement board and will keep searching the internet for additional advice.

    Oh, I haven’t tried it yet, but will certainly use a different SCSI cable for the Zip drive than the factory original. Thanks Emma for that bit of info.

    I’ll keep everyone posted if and when I get a solution to the problem.

  8. Update 2/7/2016

    Well for now I’ve given up on SCSI for the ASR-10 rack. Yesterday I removed all of the PCB boards and check all four SCSI connectors on the SCSI board for continuity. All seemed to work 100%. Before that all of the connectors were replaced along with fuses. I also tested with a Zip Drive 100MB which worked on a friends ASR-10 keyboard. I have an ASR-10 formatted zip disk as well.

    The ASR-10 works amazingly well with the one exception of the SCSI. I don’t get a “SCSI installed” or “Searching for SCSI devices” message at all. It’s as if the SCSI board is not installed, but it is of course. ( Note magically it all appeared ONCE when booting up, but since then have never been able to get the rack to detect the SCSI board again. )

    So, for now, I’ve elected just to work with the floppy and look for the ASR-10 keyboard version for future SCSI use.

    The SCSI in the rack is probably just garbage now and may just give it away for someone here in Japan to work with and try and fix.

    Now it’s on to making music.


  9. thepocketsizedworld

    I just got an asr10 same problem with scsi board, i took it out resoldered the board.

    It seems to work better

    The scsi board had some really bad soldering, holes in all joints.

    Try that it might work.

    Alternative is you can purchase a remade scsi board and di online just google it.

    I have tried acard to cf it wont work.
    Most likely because of old fashioned hdd lba mode ( anything above 4gb if i remember )

  10. thepocketsizedworld

    Found this artmix wordpress blog about ensoniq asr scsi fitting pcb.

    I emailed him about the asr 10 and he said they will make them in the summertime. !!!!!

    I also retested my acard to ide 7720u and it works great externally.

    WordPress blog info about asr pcb


    The company is in japan and has ebay shop called artmix they also sell scsi to cf boards !!!!

  11. Lino Manelli

    I have the same problem here with four SCSI Zip Drives! The CD Rom SCSI works flawless on the ASR 10 Rack and the keyboard, but the Zips are not recognised on startup. Even if daisychained wit the CD Rom, the whole SCSI Chain is not recognised.
    Sx month ago I formatted several Zip disks with that setup, now nothing works anymore.

    Cables seem to be fine, Power adaptor is fine, SCSI Board on ASR side is fine too.

    I resoldered one of the Zips, but no cure…

    Will report, when I found a solution

    1. Lino Manelli

      Solved the damn problem 🙂 Had three! damaged Zip disks, non of which was working. Took a new one and the Zip fired up flawlessly, was recognised, got it formatted, put OS on it, works like a charm.
      cheers, Lino

  12. Alex

    Hi Guys, the is a guy (Facebook Ensoniq Group in Germany) that sells a little interface board for the ASR10 that avoids the scsi interface and connects straight to the mainboard providing IDE, SCSI and other formats. I heard this from a reliable source but did not check it out yet.

    Might be of help.
    Cheers Alex

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s