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Bottlehead Kits => Crack => Topic started by: Rix__Mix on October 24, 2017, 07:01:47 AM

Title: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: Rix__Mix on October 24, 2017, 07:01:47 AM

Hi all

I'm getting no audio on the left channel and the A3 LED is not lighting. Main voltage is 240v.

Voltage testing is off, whilst I was conducting the voltage testing I saw some smoke coming from around the top left capacitor (14u).

1. 42v (OK)
2. 64v (Not OK)
3. 0v
4. 19v (Not ok)
6. 0v
.... Testing stopped and power pulled due to smoke.

I'd appreciate any help please.

Please see below for photos:

(https://i.imgur.com/uSumMzm.jpg)

(https://i.imgur.com/JKX79vz.jpg)

(https://i.imgur.com/ZBQGsII.jpg)

(https://i.imgur.com/VJlwp7l.jpg)

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: Paul Birkeland on October 24, 2017, 07:03:16 AM

One of your blue 100uF capacitors is not where it's supposed to be.

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: Rix__Mix on October 24, 2017, 07:35:41 AM

Thanks for the really quick response!

I've moved it over to where it should be, voltage checks are now all good and it works wonderfully!

Thank you again Caucasian Blackplate.

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: fullheadofnothing on October 24, 2017, 07:41:21 AM

Your input jacks are mounted incorrectly.

It looks like one of the UF4007s at 19 isn't in the joint, it's just tacked in place with a solder blob.

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: Paul Birkeland on October 24, 2017, 08:51:49 AM

Quote from: fullheadofnothing on October 24, 2017, 07:41:21 AM

Your input jacks are mounted incorrectly.

Good catch.  That mistake forces the chassis to carry signal current.  No bueno!

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: Rix__Mix on October 24, 2017, 11:08:14 AM

Quote from: fullheadofnothing on October 24, 2017, 07:41:21 AM

Your input jacks are mounted incorrectly.

It looks like one of the UF4007s at 19 isn't in the joint, it's just tacked in place with a solder blob.

Hi fullheadofnothing

Can you explain a little more as to how the input jacks aren't mounted correctly?

Thanks

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: architect5150 on October 24, 2017, 11:37:33 AM

Colored insulator rings go between solder tab with and chassis with the shoulders sliding into chassis hole to insulate signal ground from chassis ground.

Title: Re: No left channel audio, A3 LED not lit, wrong voltages and some smoke
Post by: fullheadofnothing on October 24, 2017, 11:39:42 AM

Pages 12-13. There are 4 close-up pictures showing how its done.