Re: zoom 9002 troubles.can anyone help me?
Okay people, I've looked everywhere and only found incomplete references of repairing a zoom 9002 and some people claiming they did it but no details..... I just repaired two of them and will now tell you how! Open it up, there are two circuit boards- you will be working on the one mounted to the back half of the casing. You have probably heard about the IC7660 by now and this IS the problem AREA but not likely the problem. It is located on the long narrow end of the cicuit board next to the battery compartment at the very end on the bottom side of the board. This IC7660 is less than .25 inchs and is clearly marked on top of it; this chip it's self was not failed on either of my units so I left it in place. What I did change were the four capacitors on the other side of the board, starting from the end there is a 6V 10mF, two 6V 47mF, and a 16V 47mf capacitor. These are readily availible for less than $1 each, I didn't take the time to identify exactly which one had failed because that would have taken longer than just replacing all four. The capacitors are directional so pay attention and be sure to install the new ones with the the negative (black) side to the end of the narrow portion of the board as the originals are. If this does not do the trick for some reason, I would then replace the IC7660, these are also readily available for about $3, A good electronics website will even show a diagram that you can use to trouble shoot the chip by testing voltages on each leg but note the voltages will read out of tolerence when the caps are failed as well.
Both of my units had the classic no guitar sound but the metronome and tuner frequency still worked. Replacing these caps took about and hour and now both of them work perfectly. I hope this helps, I know how frustating it is to read all the dead end posts on the internet.