Smd capacitors - Page 1
Forum section: electronics / beginners

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: January 16, 2013, 05:34:50 pm
content: I am in the process of repairing something and i happened to knock one of the smd capacitor off and now i can't find it but is there anyway i could replace it with amother smd cap???

author: miceuz
author_rank: Frequent Contributor
timestamp: January 16, 2013, 05:41:40 pm
content: Might be possible. What kind of board is it? Could you post a photo of the board and the place where the capacitor was?

author: lapm
author_rank: Frequent Contributor
timestamp: January 16, 2013, 06:06:44 pm
content: next time that happens, immediatly check your shoes/socks, if that dosent help, dim room and sweep floor with flashlights light beam. So many times i have needed to do that... Sometimes not even my fault, damn cats...

author: nanofrog
author_rank: Super Contributor
timestamp: January 16, 2013, 10:45:17 pm
content: Quote from: lapm on January 16, 2013, 06:06:44 pmYou too?I keep the door to my lab shut, but they sneak in on occasion and "rearrange" the place.

author: Smokey
author_rank: Super Contributor
timestamp: January 16, 2013, 11:19:01 pm
content: Just happened to me too. Screwdriver slipped when I was prying the plastic case open and knocked off an sot23 transistor. It really made me wish I hadn't just stripped a bunch of black wire and left all the little pieces of insulation on the floor that happen to look just like sot23s.Will I learn my lesson and keep my lab floor clean from now on? Probably not.As far as fixing your broken cap, as long as the board didn't get damaged, you should be able to replace the cap. Now trying to figure out what the value should be if you can't find the original, that's the crux of the biscuit.

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: January 17, 2013, 12:51:43 am
content: Here the picIs there any chance I could just put a bigger sized cap in it's placeWill this change effect anything?

author: Gakex
author_rank: Contributor
timestamp: January 17, 2013, 01:31:39 am
content: try to find the schematic of that board and look at the cap value.

author: c4757p
author_rank: Super Contributor
timestamp: January 17, 2013, 01:50:03 pm
content: Any chance of a higher resolution picture, or at least a close-up?Quote from: Gakex on January 17, 2013, 01:31:39 amThere's no way he's going to find a schematic for it. Look at it - it's not like this is a piece of test gear from the 70s.

author: miceuz
author_rank: Frequent Contributor
timestamp: January 17, 2013, 02:49:50 pm
content: yeah, greater resolution photo would help...Did the capacitor have a resistor hearby? In this case it might have been a part of filter. This could be tricky.Or maybe it has a via to other side of the board which is connected to VCC of some chip? If so, then probably something like 10nF - 100nF might work.Another way to look at the problem is to see what chip was it associated with and on what line was it, then look up a datasheet for that chip - maybe there is a reference design schematics in there...

author: G7PSK
author_rank: Super Contributor
timestamp: January 18, 2013, 12:20:37 pm
content: Handy tip for working with small parts that I picked up when I trained as horologist, fix a sheet or old curtain to the bench then tuck it around yourself when working, any small item that would otherwise fall onto the floor will land in the sheet. The man I was working for used a large piece of wash leather for this purpose but any other material will work.

author: digsys
author_rank: Unknown
timestamp: January 18, 2013, 12:54:47 pm
content: On many occasions, you can turn the unit on without it and see what happens (providing it was able to turn on).You'll rarely find that you cause more damage, usually it'll just stop working or work "less". If that's ok,I'd try a 0.1uF - 0.0001uF and leave it at that. This is if other options aren't available.

author: vk6zgo
author_rank: Super Contributor
timestamp: January 18, 2013, 01:17:51 pm
content: I remember having a whale of a time pushing chip capacitors around an RF Power Amplifier circuit to tune it,using a toothpick.Quite often,the toothpick would flick the cap off the board.Mostly,they didn't go far,but occasionally they would disappear across the room,never to be seen again!