Flyback Transformer-How to Locate the ABL Line
Whenever there is a complaint about monitor
Contrast problem I will check on the flyback
Transformer ABL (blanking limiter)
Circuit.
Sometimes a weak picture tube might be caused
Contrast problem. If the picture tube is
well, I just go to the contrast
Circuit. The question is, how do we find
where the contrast circuit located? Simple
if you have a data sheet for the video before —
Amplifier IC, can be found in any casethe
Contrast-pin. For LM1203N video pre-amp
ic the contrast pin is located at pin 12,.
Replace this ic or trace from this circuit
to find the cause of the problem contrast.
From experienced short-circuited, usually capacitors
were, and turned up the resistance in ohms
causing the problem. A video preamplifier
may be defective. To confirm is whether
Circuit or IC problem, solder the
Contrast and pin switch on the monitor. If
monitor normal picture (contrast ok)
Then suppose that remain abl line circuit. if it
to see replace the same (dim contrast) the video
Pre-amp will usually solve the problem.
The contrast signal came from one of the pin
(Leg) of a flyback transformer, which we as
pin as abl. Many technicians have
Difficult to follow because the abl pin
usually a flyback transformer consists of approximately
10 pins. Some pins are B +, ground, AFC,ABL,
X-RAY PROTECT, VCC, HOT, HEATER, horizontal
Centering and etc. But there is a simple and
so I'm gone show you how to locate
abl pin. Use two analog multimeter set to x10kohm
Range. Connect it in series (+ probe – probe)
and measure the flyback transformer of the anode
(red cap) to all pins within the
Flyback. They all have a pen or desolder
just remove the backflow from the main board in
To obtain a preciseReading.
When shown one of the PIN diode, a
Reading, which is abl pin. The reason we use
two multi-meters, because the flyback circuit
Internally pair of high voltage diodes
connected in series. If you have a schematic
Chart or a monitor or TV
Troubleshooting book, you will see that the
internal protection diode are connected in series.
Through the combination of two meters, the output of the probe
that is enough for around 24 VOLTSCheck power
The internal flyback diodes. After
determines the abl pin, you can follow these steps to
the line and find the faulty components lead to the fact that
Contrast problem.
Television or TV flyback transformer usually
have the same design as compared to control flyback.
Whether it is a Montblanc flyback transformer
rca, Mitsubishi and Sony flyback control
is usually the same.