SOLVED Testing components help

[Grazza]

I am reasonably new to this and for my latest builds I have started testing components more stringently. Most of my components have come from Tayda and I am finding that a lot of the components are not within tolerances. Metal film resistors are not within 1% but seem close enough I think. However the box film capacitors from my latest order of components, which are supposed to be 5% tolerance are lucky to be within 25%, some as far out as 40%. I feel like in previous builds I tested a couple of them and they were consistent so I didnt bother to test a lot of them.

Can anyone tell me, is this normal? Are they supposed to be this far out? The tester I am using is this one below. I just recently bought a nice looking Fnirsi tester and it turned out to be rubbish so I am sending it back. Is there something else I should buy for more accurate results?

Also, what am I looking for when testing a diode?

And when matching a quad of transistors, how close is close enough.

A lot of questions there, I am sorry but would love help with this as I have put my building on hold as I am thinking I need to order more components. I alreasy spent a fortune with Tayda, should I be ordering through Mouser or digikey?

 

[KreoPensas]

Believe it or not, there are supposed counterfeit TC1s. Cheaper processor used and some changes on the PCB. The version with an ATMega324 is the legit one.
I did notice, you have a red dot in the upper right of your screen. That's not typical. At first I thought this may be related to the IR reader, but it doesn't mention it at all in the "user manual" or googling.
Maybe it's a low power/battery indicator?

Yup, yup. The bogus one I ended up with got de-soldered and used for parts.

 

[Grazza]

That is a pretty fair point, there would be no economical way for any of the big companies to test all their components as they go in to a pedal. I started doing it partly because I wanted to be as accurate as possible and for the sake of ruling out faulty components during the possibility of troubleshooting. I hadn't been as strict on it till this batch, but I definitely think my tester is not up to it. I've ordered a tc7 and will just check things with the DMM for now.
One last question...and maybe a stupid one, what am I looking for when I test a diode other than it works? Am I comparing VF to the data sheets?

 

[jwin615]

You can compare to the datasheet if you are testing at the same current as the datasheet.
Diodes tend to either function or not. There are instances you need to match diodes, particularly for analog octave effects or to achieve an octave effect in a fuzz, but you shouldn't need to verify against a datasheet unless you have a suspicion they are fake(zeners sold as unobtanium Ge, etc).
For matching silicon diodes, a single point of reference is good enough.

 

[jwin615]

If you know the current that the device in use utilizes, you can compare it to the datasheet
There should be a curve traced with current on one axis and forward voltage on the other.

 

[Grazza]

Cool, thanks for that