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General Category => Technical support - Hardware related => Topic started by: darvil on 17:51, 06 August 23

Title: CPC464 Capacitor destroyed!
Post by: darvil on 17:51, 06 August 23
Hello! I recently bought a CPC464 that works perfectly, and as usual, I was getting ready to clean all of it, when I realized one ceramic capacitor is completely broken, which surprised me a little, considering the computer was working fine.
I assumed it isn't a very essential component (im probably very wrong :laugh: ), but I would like to replace it nonetheless. It seems to be connected to ground.
I took a look at some schematics online but I really can't find any information about that specific cap... All I know it seems to be named C130. Maybe I just don't know how to find them properly (I still don't have much experience with electronic components!).
So anyway, I am landing in this forum with the hope someone will be able to give me some about this poor lentil  :D

The board is the medium-sized one, and I attached two images of the capacitor in question.

IMG_20230806_184627.jpg IMG_20230806_184638.jpg

Thank you!
Title: Re: CPC464 Capacitor destroyed!
Post by: Bryce on 18:42, 06 August 23
Hi Darvil,
     it's a standard decoupling capacitor, probably somewhere between 10nf and 100nf. The value isn't all that important. You can replace it with any similar ceramic or multilayer capacitor. It's probably still functioning, just with a lower capacitance, but the CPC would most likely still work fine if you removed it completely.

Bryce.
Title: Re: CPC464 Capacitor destroyed!
Post by: darvil on 19:49, 06 August 23
Awesome. Thank you very much Bryce!
Title: Re: CPC464 Capacitor destroyed!
Post by: McArti0 on 20:12, 06 August 23
C130 and C131 is capacitor 68pF

https://www.cpcwiki.eu/imgs/2/29/CPC664_Schematic.png
Title: Re: CPC464 Capacitor destroyed!
Post by: Zik on 21:56, 06 August 23
Quote from: McArti0 on 20:12, 06 August 23C130 and C131 is capacitor 68pF

https://www.cpcwiki.eu/imgs/2/29/CPC664_Schematic.png
Correct. Those come in pair together with the quartz. On the second picture above, we can read 47pF, however.
Title: Re: CPC464 Capacitor destroyed!
Post by: McArti0 on 14:12, 07 August 23
Yes Zik.! You are vigilant! In CPC464 version 3 is present 47pF

https://www.cpcwiki.eu/imgs/9/97/LeZone_464_pcb_MC0044B.jpg

Bottom right corner
Title: Re: CPC464 Capacitor destroyed!
Post by: Bryce on 14:20, 07 August 23
Oh, I didn't realise it's part of the clock circuitry. Then the value is quite important, otherwise the quartz won't start oscillating. Both 47 and 68 should work, but I would use the same value for both caps.

Bryce.
Title: Re: CPC464 Capacitor destroyed!
Post by: darvil on 15:19, 07 August 23
Alright! I will be getting a new 47pF capacitor soon to replace that one then. Thank you all for your input!
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