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…).
- Phillips screwdriver
- Digital Multimeter
- 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.
- Remove AA batteries, disconnect from power.
- Remove back cover:
With the unit upside-down, AA battery compartment at the top, remove screws, and remove back cover.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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!