RT-223 RythymTrak Hangs When Turned On – And Fix

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zoniopoda omnicolor
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RT-223 RythymTrak Hangs When Turned On – And Fix

Post by zoniopoda omnicolor » Sun Feb 12, 2017 12:44 pm

Maybe I’m not the only one who had this problem, so here is a write-up:

My RT-223 RythymTrak started to hang when turned on. It would say “ZOOM” and then just forget what to do next. The unit is re-set by pressing REC while turning on. After a second, the screen says “ALLINT”, and I press REC again. Then the unit turns on normally. This is factory re-set per the manual. But it will have the effect of erasing whatever you may have saved. The factory sounds, kits, patterns, etc., are permanently flashed onto the unit. So I could use the unit this way. Once I turned it off, it would possibly turn back on normally, but after some time, it’s back to factory re-set. Obviously, if you’ve worked on creating some patterns and other saved data, and you want to use that again, you’re out of luck; they’re gone.

I like the RT-223. But the factory re-set work-around was a bit annoying. This unit is discontinued, but I think Zoom may have out-of warranty replacements available for a fee. I decided to try to fix it myself. My fix? I changed out the internal battery, and it was a bit more involved that you might think.

My suspicion was that the unit had an internal battery which provides back-up power, etc. If so, maybe it was dead. Changing it might solve the problem. Sure enough, there is a Maxell 3V CR2032 H inside. Mine had a blue insulation sleeve around the edge. This cell however also has soldering terminals spot-welded onto the battery terminals.

In my opinion, not having a replaceable battery seems wrong. But it is not an expensive unit, and part of the unit build is likely keeping within a certain cost. I also wondered if the battery was meant to be rechargeable. But no; checking the Maxell site, the catalog page specs clearly say that these are not to be charged, including the CR 2032 H. The “H” means that it has a slightly higher capacity mAh. I am substituting with a regular CR 2032. For those interested in such things see: http://biz.maxell.com/en/primary_batteries/cr_coin.html and http://biz.maxell.com/en/primary_batteries/CR_17e.pdf

After I got the old battery off, I found some white crust at the edge of the old battery, a sign of leakage. I now want to change the battery, but I don’t want to solder directly onto the battery terminals. This just seems like an all-around bad idea (especially with a lithium cell). Besides, I want to have the ability to replace the battery. So, I got a slim profile socket holder with tabs for soldering. If I wanted to completely remove the PCB, (which I didn’t), maybe I could have removed the entire battery assembly, and replaced it with a holder. I considered putting a top-mount holder onto the PCB itself someplace, but in the end, decided not to.

Here are the steps and pics of what I did. I’m sure there are a few ways to do this, but this fix worked for me, so far. Maybe it will help someone. (Or, maybe I’m the only RT-223 fan left out here…).

Suggested Materials/Tools:
  • Phillips screwdriver
  • Knife
  • Digital Multimeter
  • Snips
  • Needle nose pliers
  • Metal alligator clip or other small clamp.
  • Battery socket such as this (pack of 10): http://www.amazon.com/gp/product/B00SUV ... UTF8&psc=1
  • CR 2032 3V battery.
  • Super glue (I used gel type).
  • Some wire (pref 2 colors).
  • Small heat shrink tube, about 1/2 inch (or other insulator).
  • Electronics soldering iron.
  • Rosin core solder.

  1. Remove AA batteries, disconnect from power.
  2. Remove back cover:
    With the unit upside-down, AA battery compartment at the top, remove screws, and remove back cover.
  3. Carefully remove battery:
    The battery will be on the left side. It has spot welded soldering terminals. I slipped a knife under the welded terminal of the (+) side, and very carefully pried the terminal off the battery. The negative side is welded too, so I had to do the same there. Another option might be to snip the battery off the terminals. That might be safer in terms of damaging something, but I wanted to have enough terminal left over to solder.
  4. Prepare battery holder:
    Strip wire ends and solder one to a (+) terminal, and one a (-) terminal. 3 or 4 inches of wire length should do it. It needs to reach the unit terminals nicely in a loop. (See step six for final position of the holder, and picture). Insert a new battery into the socket. Use a DMM and verify DC voltage at the wire ends. Getting 3V? Remove battery from holder. I chose to glue the holder to the left inside of the case. (Don’t glue it to the case yet). Since the holder is round, I glued a small piece of scrap plastic to the side of the holder to provide more of a gluing surface. A small piece of heat shrink tube can be used to insulate the unit terminals. It should fit snugly. I will not actually shrink it. Place this piece of tube onto the (+) wire for later.
  5. Solder wires to unit terminals:
    Solder the (-) terminal first. Carefully bend the (+) terminal a bit out of the way. The (-) terminal is underneath. Flow some solder with the (-) wire on top of the (-) terminal. I used a clip to hold it in place. Now, bend the (+) terminal back down and position the (+) wire such that you will be able to move the tube (which should be waiting on the (+) wire) over the soldered connection once done. Solder the (+) wire to the (+) terminal. Position the tube over the connection, making sure the terminals can’t short. If no tube is available, a small piece of electrical tape might work too, but whatever is done, they can’t touch. At this point, I inserted a battery, and checked voltage again on the unit terminals to verify the solder joint connections. About 3V? Good. You can remove the battery again for the holder gluing.
  6. Glue holder to case:
    Now, glue the holder onto the left inside of the case. Careful: If using cyanoacrylate, once it’s set, it will not be easily moved. I positioned the holder with the (+) side up, battery access pointing down to the right. This will make removal of the battery easier. Make sure that the holder will clear when the bottom cover is re-attached. You can see the plastic tabs in the case where the cover will sit. On the other hand, keep it suspended over the PCB, and not touching it. Do a dry run, then apply the glue and hold for several seconds to set. Install the battery.
  7. Re-attach bottom cover:
    Finishing touch: I put a small piece of electrical tape on the inside of the metal cover where the battery is, to make sure it will not accidentally contact it. Screw cover back on carefully: the plastic screw holes could easily strip out with too much torque.
  8. Insert AA batteries and try it out:
    I think I had to initialize one more time, but for several days now, the unit turns on correctly and retains saved data. And now, with a replaceable internal battery!

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Re: RT-223 RythymTrak Hangs When Turned On – And Fix

Post by Jim_Fogle » Sat Feb 18, 2017 3:18 pm

Really appreciate your taking the time to share your experience with us. The notated photographs show very well what you've done. I also appreciated the Maxell links and the link to the battery holder.

I agree with you that it would have been better to have a replaceable battery sitting in a battery holder but you still came up with a solution so all ends well.

Hopefully your documentation will prevent someone from trashing their machine just over a bad battery.
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