Stuck on channel A

Orange Amps Technical Q&A's

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lucantonio
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Stuck on channel A

Post by lucantonio » Thu Feb 07, 2019 5:25 pm

Hello all i am currently troubleshooting a problem with my orange thunderverb 200 amp. The amp seems to be stuck in channel A. The toggle switch nor the foot switch seem to have any effect. I have opened the amp and checked the switch to make sure it is in good working order. Personally my theory is that the internal relay may have fried due to a power tube failure I had a few months back.
I bought some new relays and I am considering replacing them but I’m not 100% sure this will fix my problem.
Has anyone experienced this before or could weigh in on my theory about the burnt out relays?

Thanks!

Jondog
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Re: Stuck on channel A

Post by Jondog » Thu Feb 07, 2019 5:49 pm

Have you tested the amps switch with the foot-switch disconnected from the amp? You might want to check the relays are getting voltage before replacing them and if so are switching and that the relay switch terminals are getting continuity if they are functioning.
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lucantonio
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Re: Stuck on channel A

Post by lucantonio » Thu Feb 07, 2019 7:10 pm

I did a continuity tests on the toggle switch and footswitch with my multimeter and they both seem to be working although they do not have any effect on the channels. As for the relays themselves it will be difficult to get a reading from them since the pins are underneath the board. My amp suffered a nasty power tube failure with arcing and everything so My guess is that the relay got a surge of current and burnt out on one side.

Jondog
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Re: Stuck on channel A

Post by Jondog » Thu Feb 07, 2019 8:39 pm

A lot of work to replace a relay if thats not the problem. If you had arcing, it's possible a trace or component that powers the relays got zapped. I had it happen to a filament trace on an amp. I'd be testing for voltages, and as far as testing for continuity on the relay contacts, you need to test on the soldered components connected to those contacts. You should have about 5 vdc going to the relay coils when the switches are activated, test with the footswitch unplugged from the amp.
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bclaire
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Re: Stuck on channel A

Post by bclaire » Thu Feb 07, 2019 11:30 pm

Just for laughs, move the switch and see if it channel switches then....

... and are you certain that you're getting full voltage out of your wall? Low voltage will stop channel switching.

lucantonio
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Re: Stuck on channel A

Post by lucantonio » Fri Feb 08, 2019 5:23 pm

Thank you both for the replies! This is a great message board and it’s nice to know there is a community out there for fixing our orange amps!

As for the power from the outlets I don’t think that is the case since I’ve played this amp at my jam space, venues and my home. It had no effect on the channel switching.

I am setting up an appointment with a tech to retube and bias the head. I am replacing the 6550s with KT88s. While we have it opened and powered up I may be able to do some voltage tests. Thanks again for your opinions on what may be causing the issues. If I am able to find the issue and fix it I will update this thread so that someone else who may be experiencing this problem can gain some insight!

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