what is this component?

[zereshki]

hello.
I want to repair a car amplifier board and find a new component that I don't know it!
it like a resistor and the same color code. but it has the letter "S" in the end of printed value on board(below the component).
for exaple : RED-RED-Black is device colors and "22S" is printed on board
or yellow-violet-brown is device colors and "471S" is printed on board





and an auto range ohm meter show open circuit for all of them !!!

Ofcourse other resistor values are as usual.

1- what is this component name and its job?
2- how to test it for is it failed or not?

regards

 

[betwixt]

It is difficult to be certain but my guess is those are capacitors and they would normally measure open circuit on an Ohm meter. to test them you would have to lift one end from the board (to isolate the effects of surrounding components) and measure them with a capacitance meter.

It is extremely rare for that kind of component to go faulty.

Brian.

 

[zereshki]

It is difficult to be certain but my guess is those are capacitors and they would normally measure open circuit on an Ohm meter. to test them you would have to lift one end from the board (to isolate the effects of surrounding components) and measure them with a capacitance meter.

It is extremely rare for that kind of component to go faulty.

Brian.

I have removed all of them and test one by one and measured by cap meter, they are not cap,in addition capacitors on circuit as can be seen from second pictures are polyester type.

here is board photo:



regards.

 

[FvM]

in addition capacitors on circuit as can be seen from second pictures are polyester type

This means nothing because a circuit will often need different capacitor types.

I have removed all of them and test one by one and measured by cap meter, they are not cap

Do you recognize a 10 or 100 pF range in your measurement? Maybe this aren't caps but I don't see an obvious alternative.

An electronic expert would "see" the most likely component type when extracting a circuit diagram from the PCB.

 

[zereshki]

ok.I will check it with low range cap meter again.
unfortunately I do not have the schematic of circuit . but generally the board parts are as I comment on board photo,may be helpful.



regards

 

[Audioguru]

The parts are shorter and fatter than the resistors and have no resistance so they are probably ceramic low value capacitors.

 

[zereshki]

The parts are shorter and fatter than the resistors and have no resistance so they are probably ceramic low value capacitors.

I measured the capacitance for color code for that one has yellow-violet-brown and printed on board "471S" was 50pf , I remove 3 ones of this component from board and all was the same !!!

 

[Audioguru]

A capacitor marked 471 is 470pF. If it is marked 472 then it is 4.7nF (4700pF). Yellow-violet-brown might be 470pF.
What does your capacitor tester say when it has no capacitor between its probes?

 

[zereshki]

A capacitor marked 471 is 470pF. If it is marked 472 then it is 4.7nF (4700pF). Yellow-violet-brown might be 470pF.

thanks a lot. but I know the procedure of reading.

What does your capacitor tester say when it has no capacitor between its probes?

My capacitance meter is calibrated and no problem for reading! it shows open circuit when it has no cap.I test a red-red-black (value: 22s) one and it is 50pf too.

Actually I think this unknown part is not cap but I don't know what is!
it is interesting that no body know this component.all just guess.

I emailed to www.boschmann.co.nz vendor of this amplifier about this component, but no answer.:sad:

 

[betwixt]

Methinks your capacitance meter tells lies :sad:

Brian.

 

[zereshki]

Methinks your capacitance meter tells lies :sad:

Brian.

but it is true for common type capacitors in pf, nf and uf range.

if really you believe it is capacitance,you think which type of cap meter can measure correctly?

 

[FvM]

if really you believe it is capacitance

Looking-glass world?

It's your problem to find out what the components are, if you need to know it. We can just guess from your arbitrarily selected informations...

 

[zereshki]

arbitrarily selected informations

the package of any component for example resistors, cap, Tr, IC ... are defined and standard,same and typical according IEEE in all over the world.
have you ever seen a capacitor with resistor shape and numbering,in addition it is most likely to cartoon bee :smile:

 

[FvM]

Ceramic capacitors with axial shape are made e.g. by Vishay (but they don't have color code) and I have also seen capacitors with color code. In so far it's well possible.

Everything else is outside my range of observation