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Logic Machine Forum › LogicMachine eco-system › General v
Cbus SHAC won't power up

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Cbus SHAC won't power up
Azar Offline
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#1
31.10.2024, 04:16 (This post was last modified: 31.10.2024, 04:17 by Azar.)
My Cbus SHAC has died, suspect it was during a lightning storm but other iot devices attached to my 24v power supply are still working fine.
After opening up the case to trace the power supply on the board I have found what looks likely to be the issue.
L2 (L2 is on the negative 24v power supply rail) in the picture looks to be damaged, anyone know what this is? Any electrical guru or board designer have any input on how to test this surface mount component?
Surely there is a chance that replacing 1 component and she will power up again, at a cost of $1500aud surely it's worth fixing or at least trying.
I tried to upload a picture but it's too large, ive shrunk it down so it will upload.    
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admin Offline
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#2
31.10.2024, 07:11
This looks like a ferrite bead filter. For testing purposes you can simply remove the broken filter and connect both pads together directly.
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Azar Offline
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#3
31.10.2024, 07:38
(31.10.2024, 07:11)admin Wrote: This looks like a ferrite bead filter. For testing purposes you can simply remove the broken filter and connect both pads together directly.

It is connecting the ground rail to the input of the 24v negative power supply rail. The undamaged component is providing 0 ohms reading and the damaged component is giving 1.9KOhms
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admin Offline
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#4
31.10.2024, 07:42
So have you tried shortening L2 pads to see if the device boots or not?
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Azar Offline
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#5
31.10.2024, 08:03
If it fires up when shorting across the component do I then get a replacement ferrite bead? Or just leave it shorted??
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admin Offline
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#6
31.10.2024, 08:10
It's better to replace both beads with the same component like BLM21PG221SN1D. But it should work without beads if nothing else is broken in the power supply path.
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Azar Offline
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#7
12.11.2024, 07:17
I have tried to power unit up, tried shorting across L2 pads and nothing.
I have found C99 (capacitor I believe) on the top board just below the usb-B connector that has flash marks coming from it.

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JMemphix Offline
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#8
13.11.2024, 04:33
You could try the electronic guys that repair the C-Bus touch screens... I'd expect it will be around $300 plus parts.

Best regards
Trevor Callaghan
Workshop Manager
0404 887 463
trevor.callaghan@jeatech.com.au

JEA Technologies
Unit 36, 41-49 Norcal Road
Nunawading Victoria 3131
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