C25 Capacitor on the Matrix Controller Board - Value Anyone?

[phenoptix]

I've offered to repair a customer's controller after they botched a LED swap job, I assumed it would be a blob of solder somewhere and have given them a price of parts and postage (thought it might cost them £1 as didn't expect to need parts!). Seems the C25 capacitor and the R21 resistor have been swiped off with the soldering iron. I've tested the R21 with a multimeter and its 330 Ohm, with a 0402 form factor. The cap is also 0402 but I don't know the capacitance and my meter is pretty basic. I could probably get the parts for less than 10p and save the controller.

Anyone know or could measure the value for me? A pic showing the location is attached - edit - uploader file is full. The cap is between the big grey lump at the top and the sync button.

Seems they've also lifted the entire trace as well, good thing thats a 5 minute job too!

[RDC]

C25 is just a filter cap on one of the PnC lines, it's fine with it missing.

[phenoptix]

Thanks for that. Excellent news, I was going to buy a new multimeter this week. Now I'll just replace the resistor and see how it goes!

[RDC]

Welcome.

Most times when one side of the Capacitor goes to Ground then it's for DeCoupling on some DC line, and most of the time it will be OK to just leave it off or replace it with some typical value, 0.01, 0.1 or 1uF and it will be fine.

If neither end goes to Ground then it's for Coupling, and should be replace with the same value.


In both cases, replacing it with the same value is what's best, but for DeCoupling caps that can be fudged to an extent.

[phenoptix]

I've ordered the resistor now, so hopefully tomorrow I can get the controller fixed for our customer. Cheers again for the help.