My JMP-1 MIDI preamp had a low battery problem (it often displayed "E" when powered on and sometimes, when it was not in use for more than one day, it would lose some of the settings). All this is hardly surprising because it still had its originaly battery, which means it was about 20 years old! So I brought it to a local tech to have a new battery installed, and I requested they fit in a socket and a removable battery so that I would be able to replace it myself in the future, without desoldering. I got the preamp back today, after about 40 days sitting in their lab. The tech said that when he opened it up he found the original battery had leaked onto the board. I suspect this may have been caused by the fact that they let the unit sit there unplugged for 40 days (they admitted having "forgotten about it" despite me calling them three times in the course of these 40 days) until yesterday when they finally got round to fixing it. Since the battery was already almost discharged, it may have finally given away and leaked when sitting there idle... Whatever the case, the preamp seems to work now, but when I turn it on, it sometimes still briefly displays "E" at power on (it did so three times out of 20 so far, after leaving it off for a few minutes). This should not happen, as the battery is brand new (I have proof; they have given me the old soldered battery back). Or perhaps the battery they fitted in was not fresh? I just hope the leaking did not damage the board or that they haven't done a sloppy work. What do you think?