HINT: These components are most commonly damaged from not removing the power (powering down the receiver) to the vcii module before it is removed or inserted back into the receiver.
L1 & L2 will turn brown or black depending on how much current that has flown
through the device. Although this component may still be functional you
should test the resistance of the component to see if it is truely damaged
and needs replacing.
L1 & L2 are 33 uH Inductors, since inductors in most cases are simply a
piece of wire wrapped into a coil it is possible to measure the resistance
of these components. These components can be tested in the circuit because
we are only interested in either a low resistance or a high/infinite
resistance. These resistance measurements MUST be taken with THE POWER
to the module OFF, or you will damamge your meter.
Using a DDM (Digital Multi Meter) or an analog meter set your meter to
the lowest resistance value (analog would be x1) and place your meter
leads across the L1 inductor, you should measure around 2.5 - 3.5 ohms,
I have found 3.5 to be most common. If you measured a high resistance or
your meter has gone 'out of range' then this component is open-circuit
and is no longer functional and should be replaced with another 33uH
inductor.
Do the same procedure when testing L2. These resistance values may not
be exactly the same,this is fine, as long as they both measure a low
resistance then the components are good.
If you measure one of the inductors and didn't get a high resistance or
infinite resistance but one higher than 2.5 - 3.5 ohms such as 50 ohms
or high or even in the kohms range then this component is
'partially-open-circuit' and should be replaced as soon as possible.
I have heard in the past people using a temporary fix for these components
by using 33 ohm or 100 ohm resistors instead, this is NOT recommended, there is a
reason for an inductor and that is why it's there, the definition of an
inductor is a device that opposes a change in current! Opposes being the
keyword here an inductor will stop the current levels in a circuit from
changing whereas a resistor will not! A resistor is a current limiting
device only! This invalid fix may work temporarily but should not be used
as a replacement for the required components, failure to change these
components may damage your board over time! You've Been Warned :)
