circuit board / capacitor / soldering question

[wangless]

in the circle on the left there used to be a capacitor like the one in the right circle. if you can see the two little rectangles, thats where the old capacitor used to be. i removed the old cap, but i accidentally took off some of the metal contact on the board as well. i wanted to know if i could still use those contacts... just use a little more solder or something

and if anyone is wondering why.... its an attempt to fix my HUD

[AmIdYfReAk]

yes, you can re-use them.. By the looks of it they are clean.

Make sure you clean off the area, and use some decen salder with a ~20watt saldering iron.

[slipnfall]

It doesn't look like you actually pulled off either of the pads. If you want to be doubly sure that you get a good conn, take a small screwdriver, or exacto, and scrape off the solder-mask further back, untill you see copper[metal] showing thru. Clean it up with Acetone or Alchohol before soldering to help rid of dirt/oxidation. Take you soldering iron over the left-most pad, to clean off any excess solder or piece of pin the cap may have left behind.

HTH,-Jamie

[AmIdYfReAk]

the one of the lest looks like its been severed, allthough the one on the right looks clean as day.

[slipnfall]

I guess it's hard to say w/out seeing it in person. Just from my experiance, if you pull a component off w/out fully heating the solder, it will leave a white-ish colored 'pad' behind. This is from the component removed, not the board. I'm sure if he swipes that left pad w/an iron, he'll find a little piece of white material left on the iron tip, but will find the pad on the board still intact.

<shrug> Just solder the thing, you're fine. Just make note of the polarity before reinstalling it: many caps(esp electrolytics operated far below their WVDC), will 'seem' to work fine backwards('seem' as in, they don't blow up in your face right away when you power it up).

-Slip

[wangless]

so i was reading the thread off another forum, the guy said to get a 1mf 50v cap. i went to radioshack and asked the guy, who was an idiot. but he told me this one would work.

its a 1 (wierd u)F Electrolytic Capacitor. on the back it says, non-polarized, for speaker crossover: 10kHz at 8 ohms, 50 volts maximum, and axial leads

is that ok ? and how would i know which side to use properly ? thanks

[slipnfall]

Yeah that u(mu, in greek), stands for 'micro'. I'm guessing he sold you a ceramic cap; is it orange and a round disc? The non-polarized means you can install it in either direction. It will not *hurt* to use that type of cap: you can use a non-polarized in place of a polarized, but not the other way around.

That being said, w/out knowing the purpose of those caps, it's hard to say if the type is critical or not(electrolytic, the orig, and ceramic or tantalum). They each share their own electrical pro's/con's.

Just don't be discouraged if it still doesn't work afterwards: I replaced mine too w/no luck. I have found that while working under the dash w/a shop light, it heats the cluster up enough to work for a short time. The problem really relies in the entire board you are working on: IMHO, they just skimped out on their mfg'ing process and ended up with a flakey board.

Let us know...-Slip

[wangless]

it was actually like a blue cyclindrical thing. so i suppose it wasnt a ceramic one. and it totally didnt look like the cap on the right, it was like 3 times bigger.

and i actually found the old cap that i took off. would you know where i could get a cap that small, now that i can compare it to one that i would buy. or would using the one from radioshack be fine ? thanks

[slipnfall]

And you'r sure it said non-polarized?(I ask b/c they aren't usually cylindrical). Anyways, you can shop around at some of the below sites; note that the first one requires a $2-25 min order... :-( If I had some here I'd just mail one to you, but I don't.

http://www.digikey.comhttp://www.mouser ... jameco.com

[wangless]

yeah, it was a small blue round one, on the back it said non polarized. the one at radioshack only cost $1, so i might give that a try again.

thanks for the links, i guess ill try soldering it tomorrow. thanks again