Which surface mount resistor is this?

I would agree with Robert Peter Oakes on this one...

These unsoldered terminals make me shudder:

Thanks Peter and Paul.  Those aren't unsoldered terminals;  the two at each end are guide pins at either end of a slide switch housing on the other side of the board.  Two in the middle are contact pins for "ON" and the third unsoldered one is for the "OFF" position contact.

The only shuddering necessary is if you were to see my earlier greenhorn soldering attempts on the other PCB that has the missing surface mount resistor.  When I get a new SMR for it, I'll try to use my new Hakko iron, 65/35 solder, flux pen and flux remover pen, and hopefully better technique to clean that mess up.  With age has come a tremor that makes fine-circuit soldering particularly difficult, even with "helping hands"/magnifier, so results aren't always as pretty as I'd like.

I guess I'll go for one of the "1101" resistors in Newark's catalog.  I take it that it doesn't matter in this application what the resistor's specifications are, such as milliwatts, voltage, case style?   http://www.newark.com/webapp/wcs/stores/servlet/Search?catalogId=15003&langId=-1&storeId=10194&gs=true&st=surface%20mount%20resistor%201101

Joel

hafcanadian

Glad it was useful.

I think you'll see form the ilnk you only need to be close to work out which of the packages it is, so the width should be enough.

From your measurements it is an 0805 package.

I did suggest cutting the track to measure it with an ohmmeter, but I don't think 90 ohms will make a difference as I suspect it is simply a pulldown for the pin.

I struggled with my old Weller handpiece, using fine sandpaper to clean its tip (gag)

Removing the plating is not the best way to encourage the solder to stick.

I would use the steel wool type tip cleaners, that are available from here, or in your local supermarket.

There was a discussion here.

http://www.newark.com/weller/t0051384199/brass-wool-replacement-wdc-2-pk2/dp/71R4748?ost=1792732

Mark

Even better of course would be the dedicated tip cleaning products like those brass tailings in a tray with some flux on them.

Much better than the old damp sponge and very mildly abrasive to clear off the oxidized clag.

http://cpc.farnell.com/pro-s-kit/sh-1025/cleaner-soldering-tip/dp/SD01015?ost=tip+cleaner&categoryId=700000008630

Yes, thanks Guys.  The Hakko (model FX888-23BY) came with an iron rest that includes a really nice sponge and a brass wool pocket.  I've found I don't really use sponges anymore, although in my earliest years I didn't use them at all (didn't know any better).  The brass wool alone and cleaning by tinning with flux core solder has been keeping my new iron tips beautiful, so I don't bother wetting the sponge. 

Someone told me one reason for my noticed improvement is that the Hakko uses ceramic tip cores, so the heat is better controlled than on my simple Weller and Dremel wands.  I "learned" initially with Dad's old 1950's Weller 2-level triggered gun, but it was heavy and the heat hard to control;  not much good for today's fine electronic PCB's.  They still sell a similar one today, but it's not as well built - overseas quality shall we say.  So I keep Dad's around for heavy automotive soldering, etc.

I ordered a Vishay Dale thick film resistor, 1.1 ohm, 125mW, 150v, at 1% tolerance earlier this afternoon, so you've confirmed my dimensional analysis at 0805 (Newark part 52K9729).  Seemed silly... the SMD was 8 cents, the shipping $6;  but I needed no other components at the moment.  Go figure, they can't put that dinky thing in an envelope and mail it for 49 cents.

Joel

Im hoping you meant that you ordered a 1.1Kohm, not a 1.1ohm or your now talking about a different resistor than earlier otherwise your in for another 6$ SMD resistor

the SMD was 8 cents, the shipping $6

I tend to get 10 - 25 of them as eventually one day you will need them.

I also tend to get other values at the same time ...

Keep them in a sealed plastic bag ... they'll be fine for years to come.

Mark

Yup.  My bad.  I meant it is 1100 ohms.

OK, lucky you , for that price I would have ordered a few other ones to play with as you have to pay the 6$ anyway... Ah well

I thought about getting more, but I look at any one board I come across and I see all different numbers on the resistors.  On Amazon, and maybe on Newark (I didn't look), they seem to be selling packs of assorted SMD's.  But there are so many, I didn't have time to peruse them all trying to find the optimal mix of potential future needs.

Joel

hafcanadian

Joel

There are a standard range of values E6 to E192.

http://www.logwell.com/tech/components/resistor_values.html

Even if you just went for the E12 values, you'd be covered for most things.

so 10, 12, 15, 18, 22, 27ohm, etc

100, 120, 150ohm, etc

1.0k, 1.2k, 1.5k etc

10k, 12k, 15k, etc

100k, 120k  ..... you get the picture

For most microcontroller work a 220ohm in series with LEDs, 1K, 2k2, 4k7, 10k and maybe 470K or 1M should just about do it.

If you are designing the boards, then 0805 is a good size to handle, but other repairs might require smaller sizes.

(I have some I inherited that have no marking and look like big sand flakes.... I think they are 0201)

Mark

Well, I'm not building devices, but rather just trying to fix household items that go haywire, often due to either too much heating/cooling cycles (micro-cracked solder points) or corrosion on outside solar lights, etc.  On Amazon they offer many kits of SMD resistors.  In my life I may need 5 or 10, not thousands.  Ditto for other PCB components.

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=smd%20resistor#/ref=sr_nr_n_6?fst=as%3Aoff&rh=n%3A16310091%2Cn%3A306804011%2Ck%3Asmd+assortment&keywords=smd+assortment&ie=UTF8&qid=1431223286&rnid=16310161

Can anyone suggest a kit that a retailer offers that includes an assortment of more common components of all types?  Something like a few capacitors, standard resistors, diodes, surface mount resistors, board-mount LED's, different types and sizes of switches, etc. that a homeowner without access to drawers of components might need from time to time.  From what I've seen, the only things that really corrode out or fail are switches or LED's, or wires break at solder points and solder points develop micro-cracks from hot/cold cycling or impact.  If I knew where the original SMD for position R3 in this case got knocked off at, I could solder it back on the board and it would probably work.

But a kit full of various types and sizes of common board components would be handy.

Joel

Well, I'm not building devices, but rather just trying to fix household items that go haywire, often due to either too much heating/cooling cycles (micro-cracked solder points) or corrosion on outside solar lights, etc.  On Amazon they offer many kits of SMD resistors.  In my life I may need 5 or 10, not thousands.  Ditto for other PCB components.

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=smd%20resistor#/ref=sr_nr_n_6?fst=as%3Aoff&rh=n%3A16310091%2Cn%3A306804011%2Ck%3Asmd+assortment&keywords=smd+assortment&ie=UTF8&qid=1431223286&rnid=16310161

Can anyone suggest a kit that a retailer offers that includes an assortment of more common components of all types?  Something like a few capacitors, standard resistors, diodes, surface mount resistors, board-mount LED's, different types and sizes of switches, etc. that a homeowner without access to drawers of components might need from time to time.  From what I've seen, the only things that really corrode out or fail are switches or LED's, or wires break at solder points and solder points develop micro-cracks from hot/cold cycling or impact.  If I knew where the original SMD for position R3 in this case got knocked off at, I could solder it back on the board and it would probably work.

But a kit full of various types and sizes of common board components would be handy.

Joel

Adafruit do books for SMD resistors

0805  http://www.adafruit.com/products/441

0603  http://www.adafruit.com/products/442

Terry King does a good range of varying parts

http://yourduino.com/sunshop2/index.php?l=product_list&c=36

But if you do want quantities of other items, SeeedStudio have the OPL catalogue.

http://www.seeedstudio.com/depot/OPLopen-parts-library-catalog-c-136_138/?ref=side

Mark

Your best bet is to collect dead boards, they'll be free and you can reclaim passives quite easily.

I keep E24 resistors in 0402, 0603 and through hole from 10R -> 1M but it's a few hundred £ to start off. I only buy caps and inductors for jobs - just too many variants to keep a complete set.

MK