Only one leg needs be unsoldered to test as it is then free of the circuit. Easier to test with one leg anchored .

you do not need to remove them to test them conn meter leads if can to test a reading one reverse the leads no redig its good thats all it can do dono worry about resistance in diodes

as a rectifier ac to dc

Best to

Me too Repairing a tv with no power. I dont know which component i pulled out of the pcb. But it is a cylindrical black and it does not have on any markings. Or a silver line. Can u help what it is. Upon testing with multimeter it flows current in both directions.

@@jemsncrystals that sounds like a bead around a wire , is there clearance around the wire ?

Its not set to ohms. Its set to the diode test setting

Resistor

no

The meter sends the voltage to the diode.

Rehan Zahid if the markings on the diode are not visible, they have been erased or rubbed off, or whatever.... you merely revert to the standard procedure of testing Diodes the bottom line is this Whether it's telecommunications, Computers, Electronics (FYI, i do all of these things) and we are dealing with something , if we get a shit situation *We Deal with the Situation Logically* hence.. in Telecomms, when you get Dickheads that don't label the MDF book , you need to work with what you have. Diodes are the same but.. *Keep this in mind as well* A Diode without markings either - has Been punished or - Is Very very old which will in turn give you a hint as to the conditions of it now... the bottom line is TEST THEM ANYWAY because a) What are the changes that you are going to get a diode that has (By some act of god) Reversed it's bias, so that the Reverse Bias Voltage = 0.5 V DC and ... on top of that has Unlimited resistance in the opposite direction. hehe Mate, that would be like winning the lotto 10 days in a row one after the other, it'd never happen BUT *EVEN IF IT DID* you could then use this Diode as normal even though it's reversed because it is still behaviing like a normal IN SPEC diode the reality is .... if the markings are missing - You'll test it and.. - either it's good, so Voltage drop in one direction *OH..SORRY.. FYI So you know, When you put your Multimeter in DIODE mode, IT WILL LITERALLY send 2.0 V DC - 2.5 V DC down the probes, so.. when you set your multimeter to Diode Mode, it MEASURES THE VOLT DROP, .... Get it* so... you'll test it and Volt drop in one direction, but OL in the other direction.. this is good and by this you'll determine which is the Cathode and Anode or Volt drop in both directions, so.... you don't give a shit which is which because you'll throw it out, but, if you really want to know wel... if you had one side with a drop of 0.2 V DC and the other with 0.6V DC the side with least resistance is the Cathode 0.6 V DC would be the cathode but again.. who cares or OL in both directions in this case you can't tell which is which because both have infinite resistance in both directions. throw it out HOPE THAT HELPS

resisters have colored bands, maybe you are looking at a resister

HEHE Well, i guess you'll be looking for 20 Ohms resistance in both directions then... with LET'S NOT FORGET 5% tolerance LMFAO

I don't know enuf about this stuff to get your joke really, but it still struck me funny. Thanks for the laugh (MFAO).

pj woo ok, i'll explain it it's simple 1. Albert bain said "diodes, what if your diode has a red line on one side gold on the other side and 2 blace in the middle. Thanks" so. he is talking about a component that has the following markings Red Band / Black Band / Black Band / Gold Band 2. A diode (Usually) has a silver band one one side and the rest of it is black A Diode Does not have coloured Bands A Diode only allows current to flow in one direction (that is it's purpose) here is a picture of a diode www.google.com.au/search?q=diode&source=lnms&tbm=isch&sa=X&ved=0ahUKEwilkYrZj7PXAhXDlpQKHeKhDX0Q_AUICigB&biw=1290&bih=587#imgrc=AF7URewS3p7nlM: now.. 3. here is a picture of a RESISTOR www.google.com.au/search?biw=1290&bih=587&tbm=isch&sa=1&ei=tCQFWp3iI8Gn0AStpYYI&q=resistors&oq=resistors&gs_l=psy-ab.3..0i67k1l2j0l7j0i67k1.38300.39822.0.40096.9.8.0.0.0.0.476.902.4-2.2.0....0...1.1.64.psy-ab..7.2.899....0.lyC2wG7Bp_w#imgrc=FRYfg2fIVJI4zM: NOTICE how the gold is on one side , but there are various colours on the other side on one side of a Resistor you always get either a Gold or Silver Band to indicate it's tolerance. there are other colours, but USUALLY gold and silver is what you see and gold and silver cannot occur at the first part of the resistor also a resistor can pass current in both directions now. go to this link and select 4 Band Resistors and change the values to be Red Band / Black Band / Black Band / Gold Band www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code-4-band you will get the reading of 20Ohms Resistance with 5% Tolerance hence my comment the joke was that Albert Bain was being silly and making a joke and acting as if he didn't know the idfference between a Diode and a Resistor it was pretty obvious because as soon as he mentioned Red Band and Gold Band and just threw in 2 black bands for the sake of it , just to make up 4 bands in total it's pretty damn obvious that he was referring to a resistor THAT'S THE JOKE do you understand now Frank didn't understand the joke also he couldn't spell RESISTOR correctly hehe ScorpioX proved to be even more Naive and clearly didn't get the joke either and went onto a subject of Capacitors (Which.... TECHNICALLY, is correct) but not even remotely close to what was being said here i then came along and decided to be cheeky and a smart arse with my comment hence the emphasis *IN BOTH DIRECTIONS* clearly identifying that it can't be a diode (with a few exceptions) but generally speaking, it's common knowledge in electronics that a diode is Polarized. then you came along as far as i'm concerned, You're the only intelligent one among them hehe at least you admitted to not knowing so... that's the joke explained

We use double diodes all the time as they allow our low frquency ac signal to pass while blocking the dc power we use to detonate explosives.

+C J , no diodes can charge a battery

HowToWith GEO . base on my experience diodes can charge battery if your using a solar pannel.

I thought his voice and tone were very pleasing, first rate in fact. I thoroughly enjoyed the video in every way.