BELINEA Belinea 103052, Руководство по обслуживанию

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6. Vertical Deflection
Vertical defiection saw-tooth waveform is provided by ICH01 pin 12, 13 (VOUT1,2) and amplified
by ICV01(KA2142).
7. X-ray Protection
X-Ray High Voltage Protection circuit is to get a DC level voltage by utilizing the output waveform
of FBT pin 4 to pin 7(GND) via a rectifier consists of DH07,CH36 This DC level voltage inputs to the
pin2(X-Rey) of ICH01 TDA4841.
The preset X-Rey protection voltage is 5.2V. if the high voltage is higher than the preset voltage, the
DC level voltage input into the pin 2 will also be higher than 6.4V. It also means the HDRV signal is
off, then horizontal deflection is off and the high voltage is also off.
8. Video Amplifier and OSD Interface
KA2506-01(ICC01) is a wide band video amplifier with three matched video amplifiers, contrast
control, OSD interface, OSD contrast control, drive controls, blanking gate and clamp gate ICC01 is
controlled by I 2 C bus. H blank signal is applied to Pin 19.
During blanking all three outputs are thrown to the pedestal level.
A insert H-Sync is used to a clamp signal. The signal is applied to Pin 18.
Three OSD inputs (Pin 1,2,3 of ICC01) are TTL compatible and typical bandwidth is 80MHz.
A fast commutate pin is provided to select either the video or the OSD inputs as a source for the
amplification.
OSD contrast controlled by I 2 C bus.
MTV021(ICC02) is a high performance HCMOS device designed to interface with a micro
controller unit (ICM01) to allow colored symbols or characters to be displayed on the monitor screen.
The output stage is made of 3-channel power amplifier (ICC03, LM2435T).
The output capable of 40 volt swing in less than 7 n Sec.
The three cathodes are AC coupled to the video amplifiers.
The DC level on each cathode is set by a cut-off amplifier and clamp diode.
Trouble Shooting
1. Instroduction
This trouble shooting guide is arranged by fault conditions. Following each fault conditior a check for
a signal on condition to be answered YES or NO.
For NO answer proceed to the right and continue until the fault is located.
For a YES answer continue in the left column to the next numbered check.
Again followed this procedure until the fault is located.
2. Trouble shooting procedure
When Trouble shooting this monitor, some precaution should be observed.
Never connect primary ground and secondary ground together including use with an isolation
transformer.
Measure high voltage with respect to chassing ground only, and with a high impedance probe of 1000
mega-ohm or higher and rated for 30KV DC or higher.
Measure QH09 collector pulse with a high quality 100:1 probe rated for 1500 volts or higher.
3. Trouble shooting procedure
Symptom
a) Image is scrolling
Check(YES)
1) Check for V-sync at Pin 32 of ICM01
2) Check for positive going V-sync at
Pin 14 of ICH01
3) Will V-oscillator is locked with input
signal
Pin 24 of ICH01
4) Check V-ramp at Pin 13 , 14 of ICH01
Action(NO)
Check 15 Pin connector ZDM02
Check ICM01, ICH01
Check CH02
Replace ICH01.