JC-120 in need of a lot of love

[Pepe]

Man, that sounds like the amp needs TONS of love.

[laurie]

Chassis stripped, cleaned and clear-coated to stop further corrosion.

It really does look like this amp was left outside for a couple of years. The patch of corrosion near the middle is directly under the bolt that holds the handle. It appears that maybe it was rained on/snowed on/spilled on and the liquid dripped into the chassis. That might be what killed the amp board - the liquid inside shorting something out?
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JC-120_5.jpg (120.87 KiB) Viewed 8025 times

[Pepe]

[The_Doc]

Just a scratch - should buff out

This one really is in a mess and I can’t imagine how that could happen to such a great amp.

[laurie]

This one really is in a mess and I can’t imagine how that could happen to such a great amp.

I think it failed years ago and the repair cost may have been more than the owner wanted pay? Who knows?

[laurie]

This is what the upholstery tacks look like for the trim. Humidity in Calgary is non-existent. This is from wet cabinet wood.
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JC-120 upholstery tack.jpg (178.35 KiB) Viewed 7971 times

[laurie]

Starting the slow process of putting it back together. I've removed the broken 110V service outlet, and replaced the broken power cord and fuse holder. I've also used a proper industrial gland for the power cord entry, rather than the standard bushing.

Someone before me had done a dodgy repair to the power wiring, and the fuse was in the wrong place in the circuit - the incoming hot wire should go directly to the fuse to protect everything downstream. Now fixed.
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JC-120 rebuild2.jpg (178.03 KiB) Viewed 7971 times

[laurie]

Starting the slow process of reconstruction.

The output wiring has been completely messed up, presumably when the amp board failed. The main outputs and line-out are all incorrectly wired. It would have worked with only one amp board in place, but maybe it was messed up earlier and that's what caused the dead amp board to fail? I'll never know...
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JC-120 rebuild3.jpg (158.78 KiB) Viewed 7729 times

[Pepe]

People trying to repair something. Without having the slightest clue what to do.

[laurie]

Wired up the power supply board today and powered it up. Working perfectly - correct voltages all present.

Currently figuring out the output wiring - the output jacks and the wiring to the speakers. The previous "repair" to that area makes no sense, but luckily the schematic and my own experience indicate the right way to connect it.