if you are having problems switching through presets or banks , this should probably mean that the micro switches have worn out. this instructable will guide you through a few steps on how to change them.

all you need is :
a soldering iron
a few micro switches
a screw driver
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just unscrew the back cover and be careful to put the five screws in a safe place


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as this step says, gently remove the foot switch's pcb board and, with caution, remove the cable from the pins; it is not crucial, but it will be more comfortable to solder the contacts this way


remove the defected switch and solder the new one. put everything back in order make sure the switches work before you close the processor. so... if the only problem you had was with the effect switch you're done. congratulations!

for the bank buttons move on to the next step


these buttons are a little more time consuming to change, 'cause of the place where they are mounted, but it's no harder than the foot switches.


first, you have to unscrew the jack inputs and output , then the circuit board can be removed slowly( it's not screwed to the chases )
one you get to the actual circuitry, remove the two screws and turn the cover and remove the knob buttons by just pulling them out. remove the nut and then you can remove the defected buttons and replace them.


screw all the circuitry back on, connect the cables to the pins, check once more for the buttons to work , close the back cover and you're ready to rock with your favorite multi effect processor that responds like the first time you turned it on.

please excuse me if i made any expression mistakes and if i'm unclear in any of the steps; it's my first instructable.
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I'm Of Brazil and need two of this micro switches how the Banks and Rythm ... Someone have this to sell me , send me please... I Need So much of this! Or know where to found this.

LukaszS22 days ago

You may also try just to refresh the solder. I fixed a problem with my rhythm micro switch that way, without changing micro switch itself.

Hey All, I have Guitar Effect Zoom G1X, I had trouble on PCB mount jack input & phones output, does any body know where I can get the spare part original for ZOOM PCB? thanks

cesarquienmas5 months ago

Hey guys, I have this problem with my g2.1u. The thing is that it has that blinking "bt" message on the display, but I'm using zoom's ac adapter, do you know If I have to replace or change something? Please let me know

Noite Boa, Sera Que alguem poderia me FALAR quali EO IC10 POIs uma da Minha G2 torrou e ficou Impossível de sabre E quali.

DESDE JÁ agradeço.

Noite Boa, Sera Que alguem poderia me FALAR quali EO IC10 POIs uma da Minha G2 torrou e ficou Impossível de sabre E quali.

DESDE JÁ agradeço.

Stevie4218 months ago


I was hoping someone could help me. I was using my G2.1u today into my keyboard with the rhythm section going, no problems at all. Have been doing this for quite a while. All of a sudden, no rhythm section. I don't think I hit any buttons but it is possible.

Nevertheless, nothing I do can get the rhythm to come back. Is there a setting I'm missing? I'm inclined to believe it is the actual button on the unit isn't working because while I can hear all the guitar effects in my keyboard (delay, drive) when I press "rhythm" it doesn't bounce over to that mode and let me modify tempo or pattern. It's not getting to that section.

I don't know how the button could have just broke though. This unit isn't used in performance. I'm pretty gentle with it and use my fingers, not feet.

Please help! I need the rhythm section to work.


Bokey Jocic11 months ago

Please send me some info about burned transistor Q2 (6CN). Is there any replacement?

i think Q2 is the same as Q3 & Q4,
that's a BC817. and replacement that could work maybe BC337. here is the
datasheet ... good luck!

kirk777 kirk7779 months ago

RECTIFIYING: Q3 & Q4 are BC807 (NOT BC817). because BC807 its PNP polarity, and BC817 the NPN version.

Thus replacement will be BC327 and NOT BC337 in TO-92 case.

Thanks, works well with the replacement.

so you made it? i didn`t try yet because i can't find bc337 far
away from the city, but if works to you i'll buy a couple of them by
internet and wait 'till they come.

kbaurhoo9 months ago

my zoom g2.1nu wont remains on the menu where its shows G2.1NU Ver:1.03..please help me. I hope u can help guys..thx a lot

kirk777 kbaurhoo9 months ago

did you try to update the firmaware or reset?

kbaurhoo kirk7779 months ago

still the same... :(

please help

kbaurhoo kirk7779 months ago

can u please tell me how to reset or update the firmware!! u r very cooperative ...thx a lot man

kirk777 kbaurhoo9 months ago

Basically you must conect the pedal to your pc, download the firmaware from zoom's web and run the software.
In the user manual you can find the complete instructions to do it, but if you don't have it here is an online version.

jagrae11 months ago

Hi Guys,

Thanks for all the valuable info. I am a G2.iu owner and I love it, but I have an insurmountable problem for which I find no remedy. ( Even after reading the manual thoroughly .)

At last power up, all I got was a blinking edit light and nothing more. Power modes for battery and DC are functional, but no USB and no coms with laptop.

The juice is flowing through, as you can hear the output connecting with the amp at power up, but no boot up of the Zoom processor occurs.

I have had some problems with power surges and lightning strikes in the past so I imagine this might have toasted something fragile.

This is a great piece of kit and I would hate to lose it. Could anyone please suggest the next step in diagnostics, as I will have it repaired by an expert if necessary ,if possible and affordable.

Could it be a ribbon connector or am I being optimistic?

All The Best . . .

kirk777 jagrae9 months ago

Have you check the common failure of Q4?
or maybe another transistors like Q2, Q3 Q5 or Q5? If so, replacement
could be BC817 or BC337. I`m sure it works for blinking led, but not
sure about usb power.

Also you must check ribbon conector integrity.

good luck!

kirk7779 months ago

kbaurhoo9 months ago

my zoom g2.1nu wont remains on the menu where its shows G2.1NU Ver:1.03..please help me. I hope u can help guys..thx a lot

krawat21 year ago

my g1xn is not starting
last time when i using it
the display shows "bt" again and again
then after sometime it stops working
i opened it whenever i m trying to start it
the resistor is heated too much
i dont know why?
when i take it to nearest electrical shop it says there is IC problem
plz, can u tell me what is the real problem and how i can fix it?

pzacarias1 year ago

Someone please, can tell me what's the value of the resistor numbered as R8, that is just next to the Q4 transistor? I have a Zoom G2.1u to repair but someone before me tried and that resistor for somehow is missing.

Best regards.
I did work on Q4. If its the one across its base/emitter leads, its 470 ohms. I remember actually measuring the value. BTW, keep us informed if you solve the "G2 will not switch on" problem. Like to keep in touch so we can share info?

Hope this helps, Erich.

Thank you very much erichans! And sorry I have taken so long to say something.
I have let the Zoom with someone with more knowledge in electronic repair, to try to fix it. It seems that applying the missing resistor on the already replaced transistor (Q4) solved the boot problem. I can't be 100% sure as it needed addicional repairs, because the previous owner done more damages than good, in his attempt to repair the unit. However the unit became bootable again, even if not fully functional, after working in the Q4.

Best regards,
Paulo Zacarias

Unfortunately the zoom G2 isn't 100% working, it have a minor problem but very limiting in it's use. The [-] BANK button when in edit mode, behaves like the STORAGE button, in other words when choosing the Drive the [-], instead of come backwards in the list of different drives, makes the display show the current bank and patch number blinking and with a second click saves the settings. Anyone have a clue of can be the problem?

Best regards.
@ pzacarias
Make sure the 20 track Display ribbon connector is properly plugged in at both ends. You get some weird results sometimes if this is not so. Make sure the offending buttons are not sticky. Again weird displays. Were the buttons spray cleaned? Be careful!! For myself, I use any good contact cleaner, spray or liquid, and rapidly exercise the buttons.

Good luck!!

Dear Erich,

Thank you for the prompt response. I will try to do what you said. However I don't think that the problem is in the display, is something wrong with the button BANK [-], or its function because it saves the settings I choose, like the storage button. Strange don't you think?

Best regards.


My Zoom it's finally 100% working, the problem were on the 20 pin flat cable that connect the buttons to the main board.

Best regards.

Great to hear!! So it was finally the 20 pin ribbon cable. So glad your processor is working. working!!

If its the one across the base/emitter points of the transistor Q4 its value is 470 ohms.

Good luck!

c67861 year ago

My G2.1u does not work on batteries. It did work yesterday though. The batteries were fully charged; trying new alkaline batteries neither worked. The battery cable is fine and is connected to the board. The unit still works with the adapter and USB power. It just wouldn't work with the batteries.

Any help you could offer is much welcome. Thanks.
erichans c67861 year ago
For the battery to work, adapter must be unplugged. I had a G2 (same thing as far as the batteries go) with a rusty contacts problem. Corrosion on the battery contacts in the battery compartment. Obviously, scrape clean! Check with a meter battery voltage is available at the CN1 battery plug. Check for continuity between battery pin 1 on the board and the number 2 point of the adapter socket (adapter plug removed!). There's often a bad contact here.

Maybe the above will get you somewhere if the Unit is working on the adapter.

I apologise if I've told you too many obvious things. Things are obvious to some and not so obvious to others!!

Rgds., Erich
c6786 erichans1 year ago

I was able to fix my g2. The DC jack was the problem. When you said the adapter must be unplugged, it gave me a hint that the problem could be the DC jack since the adapter was already unplugged from the unit. I thought maybe one of the metal contacts inside the jack got stuck so I used a paper clip to pull them towards the center. To my surprise, the unit suddenly worked. Someone must have accidentally tripped over the wire.

Thanks a lot Erich!
aghazali21 year ago
Hey man . i have a problem with my zoom G1 .. the resistor seems to be burn. can you tell my what value is the resistor .
I know you are talking about a G1! Please read what follows very carefully!

In the G2/G2.1u this is a 3.3 ohm (I guess 3 watt!) resistor. So the value in the G1 wont be far distant from that, will be around that. But please be very careful what you are doing. That resistor could have burnt out in the first place due to something it was supplying being defective (shorting).

Just to bring you into the ballpark.

hey i found this manual for zoom g1 . .. is that the value? 18ohm 2watt .
Very good url find!! However I didn't see any reference to the Processor it is applicable to from that one pic since you took a screenshot of the specific area. Could you please double check that. At first glance 18 ohms, 2 watts seems correct.
Congrats! You seem to have made a great find getting the Manual! The same site you got this info may also have something pertaining to my problems on the G2.1u too, so would be grateful for that info if you can get it. Marvellous for me if they have a G2.1u Manual and Circuit Diagram!!

Regards, Erich.
I found that info here ,
Thank you so much! I got the G1x, but could not find any of the ZOOM Pedals SM, Repair Info, etc----like the G1XN or G2.1u. Can you help me? Use your magic fingers to find me any Info, SM on any Pedal?
Did you solve your problem with the 18 ohm, 2 watt resistor?

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