SOLVED Vhs- no sound except bypass

miyagishredz

New member
I’ve built 6 pedals from pcb all with breakout boards. This is the only pedal I haven’t been able to get to work and I’ve exhausted many hours troubleshooting and looking for some help and tips please.

What I’ve done so far:
Uncased and traced the entire board to the best of my beginner knowledge with the schematic checking 3.3v pins, VREFs (which was around 4 volts shouldn’t it be 9? But it’s right after a 1M resistor so maybe not) and ground continuity. So far not finding an issue.

I resoldered leds, jack connections, and even a new switch and break out board.

Before and after equal same results. All leds come on and I get sound in bypass but no sound at all when engaged with any mode selected.
 

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Take a close look at the solder connections on pins 14 and 15 of the FV-1, and on IC2 (24LC32A).

If those are all good it sounds like the EEPROM might be corrupt. If so I'll ship you another one.
Solder on IC2 and fv-1 pin14 and 15 are all good... they looked good , but I reflowed just in case.

Something interesting to note while jumpered... When Reverb is activated , no pitch change . when chorus is activated , no pitch change, BUT if Reverb is already ON, when I flip on Chorus it drops the pitch of my guitar tone by about 1 whole chromatic step.

Still sound like EEPROM?

Thanks for all the help
 
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the effects you are hearing are the default ones on the FV1, not the programs on the EEPROM. You can take the eeprom chip out of the socket and still get those effects.
 
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the eeprom is the 8-pin chip that gets the custom programs. that was not already soldered to your PCB, was it? it is just the 8-pin IC that you need to replace.
 
It may not have been preinstalled. Maybe it was just preloaded and in the bag. I can’t remember. I built this 6 months ago, it didn’t work and I sat it aside in frustration until a few days ago and trying to figure it out since.

I enjoy the troubleshooting to a certain point until I feel defeated haha.
 
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