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Summary of Contents for IN-20258

Page 1: ...asteners or damaged connectors Also check for corrosion or damage to the finish that should be repaired C Connectors Inspect connecter body for broken parts check insulation for cracks Check pins for damage corrosion misalignment or bad plating Check for broken loose or poorly soldered connections to terminals of connectors Inspect cable clamps for pinched wires o Terminal Connections Inspect for ...

Page 2: ...t solder or solder splashes resulting from a previous repair 3 Check for corrosion at the terminal connections L Rotary Switches Check for proper mechanical operation no binding or looseness should be evident M Printed Circuit Boards Inspect for loose broken or corroded terminal connections and damage such as cracks burns or charred track Also check for insufficient solder proper binding fungus mo...

Page 3: ...T FROM EQUIPMENT ALL PERSONNEL SHOULD BE CLEARED FROM THE IMMEDIATE AREA WARNING OPERATIONS INVOLVING THE USE OF A CLEANING SOLVENT SHOULD BE PERFORMED UNDER A VENTILATED HOOD AVOlD BREATHING SOLVENT VAPOR AND FUMES AVOlD CONTINUOUS CONTACT WITH THE SOLVENT CAUTION USE ONLY RECOMMENDED CLEANING SOLVENTS ON ELECTRICAL PARTS MANY AVAILABLE CLEANING SOLVENTS CAN SOFTEN AND PERMANENTLY DAMAGE INSULATI...

Page 4: ...amel s hair or equivalent brush saturated with denatured alcohol ta remove any foreign matter from rear connecter c Clean CRT filter with a lint free elath slightly dampened with Windex glass cleaner d Open any blocked ventilation hales in the dust caver by first saturating the debris clogging the apertures with denatured alcohol and then blowing the loosened material out with an air stream 2 Perf...

Page 5: ...m connecter cleaning as follows 4 Repair a Wipe dust and dirt from bodies shells and cable clamps using lint free cloth moistened with denatured alcohol b Wipe dry with a clean dry lint free elath c Remove dirt and lubricant from inserts insulation and terminals using soft bristle camel s hair or equivalent brush saturated with denatured alcohol d Ory insert with clean dry air jet 25 ta 38 psi WAR...

Page 6: ... damage to ESDS deviees is the human body which generates and retains static electricity in conjunction with nonconductive garments and floor covering An individual can easily develop several thousand volts of electrostatic charge while simply walking across the floor or moving around in a chair Electrostatic charges of 20 kV have been measured on personnel and 35 kV has been measured on their gar...

Page 7: ...ation 1 8 21400C PART 4 All equipment tools materials and personnel at the work station must be maintained at the same electrical potential All grounding connections shall have common point and that point shall be connected to electrical ground Soldering irons shall be isolated from the power line by transformer or shall be direct current isolated The soldering iron must be grounded and have a res...

Page 8: ...or rubber in the area where ESDS deviees are handled When the operator is properly grounded contact with the operator s hand will provide sufficient ground for hand tools or ether tools that may be electrically isolated from ground 4 Special Troubleshooting Precautions In addition to the above considerations the following specifie precautions should be observed when troubleshooting or repairing mo...

Page 9: ...electrolytics note polarity markings and orientation on circuit board 2 Using a small cutting tool small diagonal cutter carefully eut off both component leads leaving about 1 16 inch of lead protruding from circuit board Remove component 3 1 1 8 21400C PART 4 NOTE If desired to disconnect only one lead for component substitution such as may be required during troubleshooting refer to paragraph 4 ...

Page 10: ...ill be done just prior to installing new component 5 If only one lead is being disconnected for component substitution during troubleshooting proceed as follows 1 1 8 21400C PART 4 a From component side grasp lead close to circuit board with small needle nosed pliers b From track side of circuit board heat point on circuit board where lead passes through board When solder melts carefully lift lead...

Page 11: ...the board Do not use excessive heat Ensure that position of component does not change during soldering 9 Carefully inspect solder joints ta ensure that excess solder has not been used and that no short circuits are in evidence Solder should fill the circuit board hale through which the component lead is inserted 10 Using small diagonal cutters or end nippers snip excess leads from components 11 If...

Page 12: ...ng component until component is removed NOTE A cup shaped desoldering tip can be used with advantage simultaneously unsoldering all leads 3 Reheat each point on circuit board from which a lead has been removed When remaining solder melts use solder sucker as required until hales in board are clean as indicated by no solder on the walls top or bottom of the hales in the circuit board 4 Using solven...

Page 13: ...ors 1 Unsolder leads and remove attaching hardware Remove transistor and insulator NOTE Aplastic insulator covers each power transistor on the rear heatsink Using a small needle nose pliers pull out the plastic plugs covering the transistor mounting screws and unscrew the mounting screws 2 Apply Thermal Joint Compound Type 120 Wakefield Engineering Inc to mounting surface of transistor insulator a...

Page 14: ...Bench Top Repair Center Silver Spring Maryland any multi lead component can be quickly and easily removed without damaging the component or the PC board H Wiring Repairs NOTE When necessary to disturb the dress of the wires carefully ensure that the original dress is maintained when replacing wires Replace damaged wiring with same size wire and color code Ensure that no bare wires are touching cha...

Page 15: ... WARNING VOLTAGE DANGEROUS TO LIFE EXISTS IN THIS EQUIPMENT REMOVE ALL POWER FROM THE EQUIPMENT BEFORE PROCEEDING NOTE References to left side and right side in the following procedures refers to your left or right side when looking at the front panel Assembly is in the reverse arder of disassembly unless otherwise specified A Oust Caver Removal 1 Loosen the two screws in the slotted hales one on ...

Page 16: ...lift the boards away from the frame and lay the boards flat on the bench 5 Unplug the two ribbon cable connectors P1024 and Pl026 from the bottom edge of the display board 6 Unplug the ribbon cable connector P1023 from the bottom edge of the processor board 7 Remove the display board with processor board attached from the frame 8 To separate the two boards remove the six screws 171 and washers hol...

Page 17: ... 5 8 inch long screws which pass through bushings on the interconnect board and are threaded into the mounting plate in the HV power supply assembly 4 Remove the four 5 8 inch screws 80 and washers securing the memory board 5 Lift the rear edge of the memory board away from the indicator 6 Unplug the ribbon cable connecter P6009 from interconnect board near the front edge and remove the memory boa...

Page 18: ...the rear connecter board and the T board 198 The sponge must be replaced in the same position 4 Carefully tilt the top of the rear panel away from the frame 5 Unplug the 20 pin ribbon cable connecter Pl006 from the rear connecter board The connecter is located along the side of the board 6 Unplug the 2 wire connecter P1019 from the rear connecter board This cable connects to the neck coil on the C...

Page 19: ...d breaking the wires soldered to the board 14 When replacing the rear panel assembly it may be necessary to unp1ug the 11 T board when reconnecting the push on whi te b1ack ground wire to the T board Be sure to replace the sponge between the T board and the connector board NOTE The small two wire connector P1019 from the CRT neck coil 192 is not keyed but is wired so it may be installed in any pos...

Page 20: ... T11 board refer to figure 5 2 for board orientation and location of the three wires with push on connecter pins Also observe that the two wire connecter P1415 has four pins and may be plugged into the board without concern for key positions CAUTION Don t forget to properly position the sponge between the T board and the rear connecter board before installing the rear panel assembly VIOLET WIRE TO...

Page 21: ... by spreading the connecter locking tabs apart The plug will be ejected 8 Remove the front panel assembly from the frame 9 If necessary to separate the control board 14 from the front panel proceed as follows a Pry off the inserts 7 on the TILT control knob the BRT control knob the function control knob and the two gain control knobs 4 to expose the locking screw on the knobs b Loosen the locking ...

Page 22: ...ver reference paragraph S A 2 Remove the front panel assembly and separate the control board from the front panel reference paragraph S H 3 Pull off the square actuator buttons from the 15 pushbutton switches 4 Remove the hex nut and lockwasher from each of the 15 switches 5 Lift the U shaped metal plate from the 15 switches 6 All switches are now accessible Unsolder and replace the defective swit...

Page 23: ...gasket CAUTION DO NOT CLEAN THE FILTER WITH ORGANIC SOLVENTS CLEAN THE FILTER ONLY WITH A SOFT GRIT FREE CLOTH AND WINDEX CLEANER K Interconnect Board Removal 1 Remove the dust caver reference paragraph S A 2 Remove the front panel assembly reference paragraph 5 H steps 1 through 8 NOTE The display board and master slave data board must be removed as instructed for removing the front pane1 3 Remov...

Page 24: ...ront of the frame Watch the ribbon cables making sure they clear the frame L High Voltage Power Supply Removal 1 Remove the dust caver reference paragraph S A 2 Remove the display board and processor board reference paragraph S B steps 1 through 7 3 Remove the data board reference paragraph 5 C 4 Remove the memory board from the bottom reference paragraph 5 D 5 Remove the rear panel and connecter ...

Page 25: ...ont 9 Refer to figure 6 1 and remove the two screws holding the CRT bracket 174 ta the lower tabs on the sides of the frame 10 While supporting the neck of the CRT remove the two screws 175 holding the CRT bracket 174 ta the upper tabs on the sides of the frame 11 Carefully remove the CRT with the yoke and neck coils attached from the front of the frame 12 When reassembling the CRT install the CRT...

Page 26: ...s or Grade EV purple larger 39025 0012 Loctite Corp No 6 32 screws or Grade HV brown smaller 39025 0017 Loctite Corp Cures in 5 seconds Grade 414 clear Bonds CRT filter gasket Locking and Sealing Compounds Table 5 2 7 Screw and Nut Torque Values Table 5 3 lists torque values ta be observed when screws and nuts are tightened during assembly of the unit I B 21400C PART 4 THREAD SIZE 2 56 4 40 16 32 ...

Page 27: ... same identifying part number 9 Degaussing the CRT The color picture tube in the indicator must be periodically degaussed to obtain optimum picture quality The tube should be degaussed before making any CRT adjustments Proceed as follows A Connect the indicator in the test harness to permit obtaining operating power B Place the function switch in the TEST position and wait for the test pattern ta ...

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