Semi-broken Mackie FW Sounddevice

[Tony Hardie-Bick]

On 04/04/15 18:20, Mikael Hansson wrote:
> Hi,
>
> My old Mackie Onyx 400F, which my son is using, is behaving badly. When
> I switch on the power the leds flash and then all goes dark. Once in 50
> tries it works fine. Does anyone have a clue to what might be the
> problem, maybe a broken power unit?
>
> I took some pictures of it in case someone can identify where I should
> start checking voltages or look for problems…
>
> http://deadmengods.com/misc/IMG_4792.jpg
> http://deadmengods.com/misc/IMG_4793.jpg
> http://deadmengods.com/misc/IMG_4794.jpg
> http://deadmengods.com/misc/IMG_4795.jpg
> http://deadmengods.com/misc/IMG_4796.jpg

dry joint or a broken track on the reverse side, may not be visible,
could be microscopic, so resolder everything anyway

before resoldering, nudge a suspected component around a bit (eg
the transistors with the heatsinks - you may be able to see movement
where the circuit or connection is broken, and how it can be fixed.

t.