Specification
Operating Safety & Handling Precautions
Input Connections & Customer Controls
Preset Control Adjustment
Removal/Installation Details
Description & Operation
Fault Isolation & Repair Procedure
Cabinet Parts Listing (Illustrated)
Circuit Diagrams & Parts Listing
Amendments & Notes

SPECIFICATION

1.   MODELS - 1431/1432
SYSTEM	1:  625 lines, 50 fields interlaced or 312/313 lines, 50 fields non interlaced 2:  525 lines, 60 fields interlaced or 262, 263 lines. 60 fields non-interlaced other non-standard systems may be suitable -consult MICROVITEC PLC.
SUPPLY	Nominal 180 - 265V, 40 to 64Hz
TIMEBASE (LINE)	Pull-in range 15 to 16KHz
FRAME FREQUENCY	50Hz - Pull-in range 45 to 65Hz
POSITIONAL ERROR	±3%
CONVERGENCE ERROR	0.6mm screen center 1.6mm screen edge
EHT	24KV approximately
EHT REGULATION	±1KV
LINE FREQUENCY	15.625KHz
DEGAUSING	Automatic at switch ON
BANDWIDTH	18MHz
RESOLUTION	452(H)x585(V) elements
DOT PITCH	0.64mm
CRT	Rectangular 335.4mm (screen diagonal) 90 deg deflection. Precision in-line gun vertical stripe screen, high voltage focus
INPUTS MODEL 1431	TTL compatible; 1500 ohm R, G, B inputs link selectable, positive or negative video
INPUTS MODEL 1432	Linear; 0 to 4V 1500 ohm R, G, B inputs. Positive video, composite or separate line and field synchronisation - each link selectable positive or negative
INPUT CONNECTOR	10 pin in-line 'SYSTEM 25' Pressac
OPERATING TEMP	0 to 55 deg C (max) open chassis -10 deg C to +40 deg C (max)
POWER CONSUMPTION	65W approx.
2.   MODELS 1441 AND 1442 14" HIGH RESOLUTION NOTE: As models 1431 and 1432, with the following exceptions:
CONVERGENCE ERROR (MAX)	0.3mm screen center 0.8mm screen edge
EHT	Approx. 24KV
BANDWIDTH	18MHz
RESOLUTION	895(H)x585(V) elements, rectangular 333mm (screen diagonal) Automatic degausing at switch on. High focus voltage in-line gun. 90 deg. diagonal deflection, 0.31mm dot pitch black matrix screen with pigmented phosphors.
DOT PITCH	0.31mm
POSITIONAL ERROR	±2%
CONVERGENCE ERROR	0.8mm screen edge
3.   MODEL 1451 NOTE: As models 1431 and 1432, with the following exceptions:
RESOLUTION	652(H)x585(V)
DOT PITCH	0.43mm
CONVERGENCE ERROR	1.2mm screen edge
4.   MODEL 2030 NOTE: As models 1431 and 1432, with the following exceptions:
CONVERGENCE ERROR (MAX)	0.4mm screen center 1.8mm screen edge
RESOLUTION	505(H)x585(V) elements, 80 characters on 6 dot, wide matrix
DOT PITCH	0.8mm
CRT	Rectangular 480mm (screen diagonal) 90 deg deflection precision in-line gun vertical stripe screen high voltage focus
POWER CONSUMPTION	80W approx.
5.   MODEL 2040 NOTE: As models 1431 and 1432, with the following exceptions:
RESOLUTION	940(H)x705(V)
DOT PITCH	0.47mm
POSITIONAL ERROR	±4%
POWER CONSUMPTION	80W approx.
CONVERGENCE ERROR	1.0mm screen edge

ELECTRICAL SUPPLY

Warning

THIS APPARATUS MUST BE EARTHED.

Important

The wires in the mains lead are coloured in accordance with the following code:

GREEN AND YELLOW : EARTH
BLUE : NEUTRAL
BROWN : LIVE

As the colours of the wires in the mains lead may not correspond with the coloured markings identifying the terminals in your plug, proceed as follows:

1.   Earth

The wire coloured GREEN and YELLOW must be connected to the terminal marked 'E' or by the safety earth symbol  or coloured GREEN, or GREEN and YELLOW.

2.   Neutral

The wire coloured BLUE must be connected to the terminal marked 'N', or coloured BLACK.

3.   Live

The wire coloured BROWN must be connected to the terminal marked 'L', or coloured RED.

X-rays constitute a health hazard on prolonged exposure at close range unless adequate shielding is provided.

Precautions must be exercised during servicing of display equipment to ensure that the anode voltage and other tube voltages are adjusted to the recommended values.

Replace with a tube of the same type number or recommended replacement to assure continued safety.

Implosion Protection

This tube employs integral implosion protection and must be replaced with a tube of the same type or a recommended replacement to assure continued safety.

Shock Hazard

The high voltage at which the tube is operated may be very dangerous. Extreme care should be taken in the servicing or adjustment of any high voltage circuit. Caution must be exercised during the replacement or servicing of the tube since a residual electrical charge may be contained on the high voltage capacitor formed by the external and internal conductive coating of the tube funnel. To remove any undesirable residual high voltage charges from the tube, "bleed off" the charge by shorting the anode contact button, located in the funnel of the tube, to the external conductive coating before handling the tube.

Tube Handling

Wear heavy protective clothing, including gloves and safety goggles with side shields. Handle the tube with extreme care. Do not strike, scratch or subject the tube to more than moderate pressure. Particular care should be taken to prevent damage to the seal area.

OPERATING SAFETY

We recommend - after effecting any Service and/or replacement of any part of the monitor, or after any repair work - that the SAFETY CHECKS listed following are carried out.

Note

Ensure on re-assembly that ALL earth connections are replaced SECURELY; in particular safety earths and the 'P' band and dag earth 'CRT' earth connections.

Important!

Failure to observe the points noted could affect your own safety, the product's safety and ultimately, that of the user.

Earth Continuity Check

1. Using a suitable multimeter:

   Check between 'Dag' earth on the CRT and mains plug earth pin, (safety earth connection). The reading should be less than 470Kohm (with tube discharged).

2. Check mains earth continuity between mains plug earth pin and:
   1) CRT 'P' Band

   2) PCB 'Earth' pin on main chassis

3. The final assembly/housing should be checked for continuity between the mains plug earth pin   and ALL exposed metalwork.

   Note

   Tests b and c should have a resistance of less than 0.5 ohm.

1. On the mains supply 3 pin plug, - check between 'live' and 'neutral' to 'earth'   for leakage breakdown.
   This test should be made with 1.5KV to 1.6KV AC or DC equivalent.

   On Test

   1) No breakdown should occur.

   2) Earth leakage should be less than 6mA at 1.5KV.

2. Insulation resistance should be greater than 2Megohms at 500V DC.

   CAUTION

   A MONITOR FAILING ANY OF THE ABOVE CHECKS MUST BE RESTORED TO SAFE WORKING CONDITION BEFORE BEING RETURNED TO THE USER.

SAFETY STANDARDS

UNDER NO CIRCUMSTANCES SHOULD ANY FORM OF REPAIR OR MAINTENANCE BE ATTEMPTED BY ANY PERSON OTHER THAN A QUALIFIED ENGINEER.

Switched Mode Power Supply

Although the outputs from the power supply are isolated from the incoming mains supply, the bridge rectifier and the control and regulation circuit ARE NOT isolated. Therefore, when servicing the power supply section of the chassis assembly, the SMPSU should be supplied by a MAINS ISOLATION TRANSFORMER OF AT LEAST 300VA RATING.

HANDLING PRECAUTIONS

HT Electrical Charges

The power supply section remains charged with respect to chassis for 30-60 seconds after switching off. Care should be taken when handling the chassis to avoid touching this area during this time.

EHT Charges - Horizontal (Line) Output Stage/CRT

Before handling or attempting adjustment or replacement on the horizontal (line) output stage or on CRT areas - always discharge the final anode of the CRT - by using a suitable EHT probe only. Do this by connecting first to CRT dag earth coating/earth braid assembly, and then to CRT final anode/anode button 'poppy' connector.

Please Note

Very considerable electrical charges can be stored in these areas - even for lengthy periods of time after 'switch off'.

In the interests of your personal safety observe the precautions listed.

Components marked  on the parts list and circuit diagram are safety approved types and they should be replaced only with components supplied or approved by our Service Department. It is also recommended that the components not marked with the safety symbol should be replaced by parts of the type originally fitted, and this applies particularly to those resistors which are stood off the printed circuit boards.

HANDLING PRECAUTIONS - STATIC ELECTRICAL CHARGES

Depending on equipment type and model, the equipment may contain devices which may be damaged by static electrical charges during handling. Generally, these devices are indicated by a  symbol.

When replacing or handling these devices or PCBs containing such devices, care should be taken. Soldering irons should be earthed and personnel should use wrist straps earthed via a 1Mohm resistor. If the latter is not practicable they should discharge themselves of any static electricity by touching an earthed point

Static sensitive devices should be packed in suitable conductive containers.

Note:

Electrostatic discharge does not necessarily 'kill' a component completely - more likely it will 'wound' it.

Many static wounded devices will pass normal test both on site and in Service Workshops. In this respect PCBs containing such 'wounded' devices are a major cause of 'no fault found' problems.

It pays, therefore, to cultivate static safe ways when dealing with such static sensitive equipment

INPUT CONNECTIONS & CUSTOMER CONTROLS

T.T.L. compatible or linear (0 to 4V, 1500 ohm) input level options can be selected by moving 3 links:
TL103 R,G,B located on main PCB:
position 1 corresponds with linear levels
position 2 with T.T.L. levels
NOTE: Contrast control VR111, inoperative when position 1 is selected.

Sync inputs must be T.T.L. compatible, the timing of sync pulses should approximately correspond with those used for broadcast purposes (see fig.1 below for available options.)

To facilitate inversion of T.T.L. compatible video input signals by either moving link TL101 on main PCB to position 1, or removing TL101 and feeding a positive T.T.L. level in to pin 9 of PL101.

NOTE: Monitors are normally despatched wired in composite negative (going) syncs mode, with TL102 not fitted, and TL106 selected to position 1.


Signal input pin connections
Fig. 1

KEY
 1 = +12V
 2 = No connection
 3 = Sync 3: field sync
 4 = Red video
 5 = Sync 2: field sync
 6 = Green video
 7 = Sync 1: composite or line sync
 8 = Blue video
 9 = Normal/inverse T.T.L. video
10 = Ground

SYNC OPTIONS	INPUTS (PL101)	LINK POSITION
MIXED -ve going +ve going	pin 7 pin 7	TL102 not fitted TL106 in position 1 TL102 fitted TL106 in position 1
SEPARATE -ve line -ve field +ve line +ve field -ve line +ve field	pin 7 pin 5 pin 7 pin 3 pin 7 pin 3	TL102 not fitted TL106 in position 1 TL102 fitted TL106 in position 2 TL102 not fitted TL106 in position 1

NOTE: On 'D' series monitors the controls listed below are located on the front of the monitor, concealed behind a downward hinging door.
1. ON/OFF Switch
   Mounted rear of the monitor, allows mains to be switched on and off without switching the mains supply off.

2. Contrast/Brilliance Adjustment (VR111)
   Mounted rear of main PCB, only active in T.T.L. mode, and allows video gain to be varied from maximum to minimum, at black level.

3. Brightness Adjustment (VR134 when fitted)
   Mounted rear of main PCB, next to VR111. Active in all modes of operation allowing brightness of display to be varied above or below cut off.

4. Volume/Audio Adjustment (when fitted)
   Mounted rear of the monitor, allows user to adjust volume/audio level of the monitor. Clockwise to increase, anti-clockwise to decrease.

5. Colour Saturation Control (when fitted)
   Mounted rear of the monitor, allows user to adjust the colour level of the monitor. Clockwise to increase, anti-clockwise to decrease.