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Mini³- left channel not working, high Quiescent Current

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Mini³- left channel not working, high Quiescent Current

Postby jaybeaster » November 22nd, 2019, 9:17 pm

Hi I'm new to the forum/AMB in general. I was looking to pick up the Mini3 as a intro project and it's been fun so far!
I'm having an issue though, I'm not getting any sound whatsoever from the left channel. No Static, no hissing, nothing. The volume boosts well in the right channel and it sounds great.
I did the initial check and everything looked good except the Quiescent current. I was reading 44.2 mA. I dug around in the forums before deciding to post and another guy had a similar issue and I believe his U5 was blown? But he had audio in both channels.
I reflowed the entire board and checked for any shorts/bad solder joints and I can't see any. Should I just go straight to replacing the U5 or are there other steps I should take?
I'm new to a lot of this so any help/advice would be greatly appreciated!
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Re: Mini³- left channel not working, high Quiescent Current

Postby amb » November 22nd, 2019, 10:51 pm

If only one channel isn't working, then your U5 is probably blown. If U4 had blown, you would still have audio in both channels but it would sound "weird" (because you'll hear the difference signal between the channels only, on both sides).
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Re: Mini³- left channel not working, high Quiescent Current

Postby jaybeaster » November 23rd, 2019, 6:17 am

Okay, that's great info. I'll order a new one. Would that also be the reason for the high Quiescent current?
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Re: Mini³- left channel not working, high Quiescent Current

Postby amb » November 23rd, 2019, 1:33 pm

Yes, high quiescent current is a symptom of a blown opamp. Be sure to read the Mini³ website "Initial check" page, under the "Notes" section about replacing the opamp.
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Re: Mini³- left channel not working, high Quiescent Current

Postby jaybeaster » November 23rd, 2019, 3:19 pm

Okay, thanks for the help! I'm impressed at how long this forum has been active!
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Re: Mini³- left channel not working, high Quiescent Current

Postby amb » November 23rd, 2019, 4:03 pm

jaybeaster wrote:Okay, thanks for the help! I'm impressed at how long this forum has been active!

The forum has been up for 9.5 years as of now. AMB DIY audio resources website and shop since 2005. We’re here for the long haul! Good DIY audio projects never go out of style.

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