Saturday, February 20, 2010

Unseen problems with buying SMT components.

Having just rung the Supplier as my last order had the wrong device supplied. I now find when taking pictures for my Micro Stepper to post on line here,  that the resistors supplied in my order at the beginning of the month are the wrong value.!!

Even with my 5 x magnifying head set on I could not read the value it wasn't till I snap a blog picture and crop it that I can see my 0.75 ohm resistors are actually 0.33 ohm.

So I now have one 74HC244 that's pretending to be AD595AQ chip that's been put on the rack or had 4 extra legs implanted.

I found this yesterday and went off shopping cross with my self for ordering a different type of Thermistor amp. It wasn't till the evening I got a magnifying glass out to see why I had ordered the wrong device.
That i saw it wasn't me but the device that was wrong. Ahhhhhhhh.

And now I find that 15 of my 0.75 ohm resistors are actually half  their former selves at 0.33 ohms..

What ever happened ISO 9002 or  BS5750 ?

Looks like I have a lost my Thermocouple test and now my  micro stepping weekend now !!

Dare I even try to use the 4 thermistors..?

I'm now just looking at the 4 glass thermistors that have no markings at all !! Except what was printed on the bag by the suppliers picking system which I now know is not that reliable!!. 

May be RS are not so expensive after all...

It takes quite a bit or me to be really irritated but this has just hit the Mark.. !!!


Unknown said...

I dont really get, why you guys dont use chemical tinner.
It is dirty cheap (I buy half liter for 3.5EUR), and it makes your final board more durable, it prevents oxidation on the copper.

Also it makes the soldering easier too.

I buy this product (TN160):

Best regards,

Unknown said...

Thank you Laszlo..

Sorry for the delay Tooth ake took over my mind soon after posting this. so I have not done much..

Thes products look good not sure if they deliver them to the UK though.

I have used TIN dip in the past and it did make the boards look better.

Not sure if it would be better when making SMT boards as the pin pitches are so tiny.
Its almost an advantage in a way that the solder is not so easy to flow on untreaed copper.