Frequency central microbus issue

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edmuggles
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Frequency central microbus issue

Post by edmuggles » Tue Apr 06, 2021 1:25 am

So I new this would eventually happen, I have managed to build a number of units with out too many issues, read nothing blew its caps at me.

Until now...

Trying to build a basic power supply from my rack.

But the 5v system really doesn’t like me and keeps popping it’s caps.
In specific these two.
I have replaced them and plugged it in again and with in seconds they where getting hot so I in plugged it before they popped again :p.

Any got any good resources on learning how to fault find?
Or any other hints.

I’m really new to diy electronics and modular synths
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khakifridge
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Re: Frequency central microbus issue

Post by khakifridge » Tue Apr 06, 2021 3:39 am

The three small electrolytic caps on the right-hand side of your picture appear to be fitted backwards. From Rick's build document: "100uF caps polarity are indicated by a square pad for +ve." The positive side is the one without the fat stripe.

pjbulls
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Re: Frequency central microbus issue

Post by pjbulls » Tue Apr 06, 2021 3:52 am

The square pad is for the anode, you put these caps the wrong way around... (also the topmost one so that one could blow up just as well).

Have a look at the build guide:
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e:
sniped :hihi:

edmuggles
Learning to Wiggle
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Re: Frequency central microbus issue

Post by edmuggles » Tue Apr 06, 2021 4:09 am

Dang thanks guys... stupid move by me

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neil.johnson
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Re: Frequency central microbus issue

Post by neil.johnson » Tue Apr 06, 2021 2:08 pm

This is why my electrolytic cap footprints have white tabs sticking out, then you align the white stripe with the white tab, and you can still check it when the component is soldered in. Never could understand why someone would put a "+" on the board when there's no "+" on the component, and worse still put the "+" marking underneath the component so you can't then check afterwards :despair:

Neil
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EATyourGUITAR
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Re: Frequency central microbus issue

Post by EATyourGUITAR » Tue Apr 06, 2021 3:12 pm

for reverse polarity of electrolytic caps, you can go blind if the cap fails when you are looking at it. DANGER! after you reverse them, even if they look ok, throw them in the garbage. it is not always possible to determine the extent of the damage by looking at them.
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF

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