Pathfinder 15R Repair

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secondhand
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Pathfinder 15R Repair

Post by secondhand » Thu Aug 05, 2021 7:57 pm

Very low signal. Can barely hear my tonez with vol and gain maxed. Internet always points to replacing the octocoupler with pics from a Cambridge. My board and components look different.

You can see it here until I figure out how to add an image.

Vox Pathfinder 15R made in Korea https://imgur.com/gallery/BiUbnr8

Image


Any ideas how to fix it or links to better instructions?
Good as the best. Bad as the worst!

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andy_tchp
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Re: Pathfinder 15R Repair

Post by andy_tchp » Thu Aug 05, 2021 8:16 pm

secondhand wrote:
Thu Aug 05, 2021 7:57 pm
Very low signal. Can barely hear my tonez with vol and gain maxed. Internet always points to replacing the octocoupler with pics from a Cambridge. My board and components look different.

You can see it here until I figure out how to add an image.

Vox Pathfinder 15R made in Korea https://imgur.com/gallery/BiUbnr8

Image


Any ideas how to fix it or links to better instructions?
Hmm, I'd be doing the 'basics' like applying contact cleaner and lubricant (ie DeOxit/Faderlube) to pots, jacks and switches where appropriate first. Does 'working' the pots back and forth improve matters any?

Optocoupler would only be relevant to the tremolo as far as I can tell(?)
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David McComb, 1987.

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mackerelmint
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Re: Pathfinder 15R Repair

Post by mackerelmint » Fri Aug 06, 2021 2:16 am

Well, they use amplifying ICs, and it wouldn't be terribly surprising if one or more had shit the bed. I mean, obviously try contact cleaner first, but replacing the amp chips would be an easy thing to try and wouldn't cost much. If you've got a multimeter, you could get data sheets online and use those to test the voltages coming off the pins and see if they're in spec without having to buy anything first.
This is an excellent rectangle

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secondhand
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Re: Pathfinder 15R Repair

Post by secondhand » Fri Aug 06, 2021 7:25 am

I gave the pots some cleaner and reflowed a solder joint that looked suspect on the trem depth pot but still no improvement.
I have a multimeter but don't really know how to use it. I think I have exhausted my skills and abilities with electronics trouble shooting.
Thanks for the suggestions though!
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mackerelmint
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Re: Pathfinder 15R Repair

Post by mackerelmint » Fri Aug 06, 2021 10:24 am

Well, in that case, try replacing the amp ICs. Socketing them while you're at it wouldn't be a bad idea. That's just simple soldering.
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MattK
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Re: Pathfinder 15R Repair

Post by MattK » Fri Aug 06, 2021 1:16 pm

You might want to look at the sockets on the back too. Something shorting the speaker out or headphone jack?

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secondhand
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Re: Pathfinder 15R Repair

Post by secondhand » Mon Aug 09, 2021 9:13 am

I gave the pots another shot of cleaner and while turning the treble pot the amp came back to life. Then died again.
I reflowed the solder joints but it stayed dead. I ordered a new pot. I hope the replacement pot will be the cure.
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MattK
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Re: Pathfinder 15R Repair

Post by MattK » Mon Aug 09, 2021 6:13 pm

Nice!

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