Korg monotron delay sound volume very low and delay not work

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Hi there guys.

I need your help. My monotron delay has stopped working.

The sound wheel is on the max and the sound coming out of the speaker is just almost impossible to hear.

The delay effects seem not be working.

I have obviously tested with off the package new batteries and also with external speakers, whose volume has to be on the max for something to be heard.

What can I do?

Thank you.

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Got warranty? Then bring it back to the dealer you bought it from :shrug:
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Unfortunately, I bought this little thing long ago and have no warranty on it.

Do you have any idea of how to fix this?

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This isn’t the best forum to ask for hardware synth repair advice. Maybe try Muff Wiggler or Analogue Heaven or SynthDIY or a Facebook group?
Incomplete list of my gear: 1/8" audio input jack.

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Cheaper to buy another one, rather than paying for repair I would think. Mine was only £20 (secondhand).

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thecontrolcentre wrote:Cheaper to buy another one, rather than paying for repair I would think. Mine was only £20 (secondhand).
most likely, unless you already have a set up for repairs. a decent soldering iron will cost more.
:ud:

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vurt wrote:
thecontrolcentre wrote:Cheaper to buy another one, rather than paying for repair I would think. Mine was only £20 (secondhand).
most likely, unless you already have a set up for repairs. a decent soldering iron will cost more.
Yeah, plus the monotrons are all SMT parts...
An idiot on Set Theory:
"In some cases there is an object called red that contains everything that is red. In much the same way a pot is a plate."

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i had it in my mind that they'd been designed with easy mods available? or did they add patch points? or am i totally imagining this?
:ud:

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vurt wrote:i had it in my mind that they'd been designed with easy mods available? or did they add patch points? or am i totally imagining this?
yeah, despite being SMT, they put well-spaced (and annotated) 'patch points' onto the board, and provided schematics etc.
An idiot on Set Theory:
"In some cases there is an object called red that contains everything that is red. In much the same way a pot is a plate."

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thanks 8)
least i know im not losing more of my mind :hihi:
:ud:

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Thank you all.

In that case, is the fault possibly associated with lack of voltage? could it be solved y soldering a specific spot on the board?

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It may well be low voltage.
The circuit diagram (schematic) is available online in PDF format.
It has a voltage converter IC1 (TPS61071) to make a 5V supply for the circuits from the batteries. The 5V supply is called VCC on the schematic. You should be able to find 2 test point pads on the pcb. TP7 is power ground and TP9 is VCC. A voltmeter can be used to verify 5v DC between those 2 test points.
The delay is a digital chip and may not work at all below about 4.5V DC, while the rest of circuit being analog might try to make some sound down to 3V or less.
Sometimes battery connector springs get broken solder joints to the pcb or just dirty spings where they contact the battery terminals.
If there is an external power adapter of socket ( I see no mention of one on the schematic), those can fail since they usually have a switch in them to disconnect the battery with a power adapter plugged in.

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Hi there, was this issue ever resolved?
I just dug up the duo and the delay and they both have the same issue ut of the blue.
They were left turned ff and without batteries in it.
But now when I turn them on there is hardy any volume, either from the speaker or through the phones output.
I'm not that known with soldering these kind f things so I hope someone found what the issue is and would like to share!

Thanks in advance!

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Same here. Seems to be a problem of age? With my unit: i don´t even think the delay is broken,but it´s just too faint because of the overall low volume...

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