"Repair
Documentation"
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--- VECTREX TROUBLESHOOTING GUIDE - QUICK REFERENCE DEBUGGING CHART--- | |||
SYMPTOM |
TOOLS/EQ. NEEDED |
TEST PROCEDURE
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PROBABLE CAUSE
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Unit will not Power up.
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VOM, Philips Screwdriver
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- Measure resistance at A/C plug (set VOM to OHMS scale
1X) should read 10 to 21 OHM +/- 5%
- CAUTION: AC Switch SW301 is located on secondary side of T101. |
T101 PRIMARY
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- Remove rear cover - REF< Pg. 11, Service Manual HP3000.
- Check Fuse F101. - Check SW301 - Turn unit onside (CAUTION: Damage can be done) and make a continuity check of the A/C switch. |
F101 Open,
SW301 open or shorted. |
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No Vector
Intermittent Vector Intensity Bad |
VOM, DMM/DVM, Scope, Shop Tools, Test Cart
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- Select Test #3 (First insert Test Cart, then turn
unit on)
- Check for +/- 5 VDC and -13 VDC at connector J204 Left to Right: -5, GND, +5, -13. - Measure AC input voltage to power supply PCB. - EP105 (center tap) to EP106 = 8.6 VAC. - EP105 (center tap) to EP104 = 8.6 VAC. - CAUTION: When replacing Power Supply wires, insure you check continuity on both sides of P/S PCB. - Check that there are no shorts between the +9 and -9 power supply to GND. (T503 (IN - T401 (IN) ). (Inductors) - Remove T401 or T503 and check that there are no shorts to GND. - Check for short between heat sink (on Power Board) and IC401 heat sink. |
D101 - D104 |
- Check Signal Waveform (X, Y, Z axis) (Red, Blue, Yellow)
at J402 on Logic PCB. Refer to Attachment 1 WAVE FORMS "A".
- Also check these same signals at EP401-404 (Y,Y,) and EP506 on Power PCB: same Waveforms as above. - Connect scope: EXT, SYNC to PIN 9 of IC302, set scope CHAN. A to .2 volts/div and Time/Div. to 1ms. |
IC303 |
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- Select TEST #4 - Check Signal Waveform at PIN 7 and
PIN 8 of IC401 (no DC level is carried) Refer to Attachment 1 WAVE FORMS
"B". Set Scope: Same as above except Volts/div = .02 Time/Div. = 2ms.
NOTE: Waveform is seen only when "DAC OFFSET" is displayed.
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IC401
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- Check supply voltage at CRT PCB PINS 2 (+40), 3 (+.3mv),
5 (-29 to +3 bightness control) and 6 (+135), (All +/- 10%)
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No Z axis is applied.
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- Check Z Axis Waveform at PIN2 of CRT socket (EP505),
Page 15.
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Intermittent or poor contact of CRT socket P501.
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- Connect Scope: Ext.-SYNC. to PIN 9 of IC303. |
Q503
Q505 Open Cable IC303 IC302 |
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Ripple in Picture, Shaking or Flashing
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VOM, DMM/DVM, Scope, Test Cart
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SELECT TEST #3
- Check ripple on + and - 9VDC and 5 VDC power supplies at T503 (IN), should be less than .05V. |
D101 - D104
C111 & C110 |
- Set Scope: Volts/Div. = .01 Time/Div. 5 ms (AC)
- Check AC voltage between GND and EP104 and EP106. EP104 = 8.5 VAC +/- 10% EP106 = 8.5 VAC +/- 10% - Set Scope: Volts/Div. 1 Time/Div. 5 ms Internal SYNC - Check Waveform at PIN 7 of T502, Refer to page 15 of manual. - Check ripple Waveform at G1 (PIN 5) CRT, PCB. (Maximum 400 mv). - Check output Waveform at PIN 10 and PIN 5 of IC401 - These waveforms should be the same. - Set Scope: Volts/Div. = .05 Time = SYNC external |
T101
C514 C515 IC401. |
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Picture distortion Pincushioning, Barreling and keystoning.
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Shop Tools, Test Cart
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SELECT TEST #1
- Loosen yoke clamp, push yoke tight against CRT bell. Orient yoke to correct axis; tighten clamp. If distortion is still not acceptable, inspect yoke magnets. |
Yoke magnets missing,
Bad yoke winding. |
Abnormal sound & picture while tapping.
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Shop Tools, Meter.
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-Do visual inspection of unit taking careful note of
all connectors, IC sockets and areas previously repaired.
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N/A
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Picture off-center, Vertical size incorrect.
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Shop Tools, Scope
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SELECT TEST #3
- Refer to Page 12 of manual - "Logic Board Adjustments". - Refer to Page 15 of manual - "Power Board Adjustments". |
Adjustments incorrect
IC305 IC303 IC301 IC401 Q301 |
Poor lettering Display, i.e., Tilt & Size
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Shop Tools, Scope, DMM/DVM, VOM, Test Cart
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SELECT TEST #4
- Do DAC O Adjustment - Do integrtor OFF-SET adjustment (Refer to page 15 of manual.) SELECT TEST #5 |
IC305
IC303 IC301 R333 R335 |
Picture size changed and unstable when input voltage
is normal.
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Scope, DMM/DVM, Test Cart
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SELECT TEST #3
- Check voltage at PIN 5 and PIN 8 of IC501 PIN 5 = 5VDC +/- 5% PIN 8 = 5VDC +/- 5% - Check waveform at PIN 7 of T502 and base of Q502, these should be the same - Disconnect C504, check waveform at PIN 3 of IC501, adjust R525 and R526 to conform to display on waveforms section. (Refer to Wavefoms, C) - Set Scope: Volts/Div. = 1 Time/DIV. = .1 ms internal. |
C501
C517 IC501 R505 T501 R527 T502. |
Slanting of Announcemnt and sub-title display.
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Shop tools, Test Cart
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SELECT TEST #1
- Display of Title Page is tilted, replace IC302. - Printing inside Title Page is slanted, replace IC301. |
IC301
IC302. |
Picture distortion - long and short of picture.
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Scope, DMM/DVM, Test Cart
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SELECT TEST #3
- Check Signal waveform at J301 (X, Y) - Compare these to Signal at R413 and R406 on Power PCB respectively (return to signal). |
Q301
IC401 Mounting method of IC401. |
No sound, Abnormal sound on CHAN. A, B or C & CPU. Weak
sound, distorted sound or noisy sound.
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VOM, Scope, Test Cart
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SELECT TEST #8
- Check for Signal on IC208 PINS 1, 4, and 5. NOTE: Chan. A = PIN 5, Chan. B = PIN 4 and Chan. C = PIN 1. - Set Scope: Volts/Div. = .5v Time/DIV. = 5 ms. - Check continuity between J302 on Logic PCB & J302 on Power PCB. NOTE: Black audio cable can not be inverted end for end, loss of audio will occur. Also insure, when you make continuity check you do not bend contacts inside connectors. - Check signal Waveform at PIN 8 of IC103 and PIN 1 of J103 (Speaker Cable), both should be the same. NOTE: The Waveforms will be different for each sound. - Set Scope: Volts/Div. = .02; Time/DIV. = 5 ms. - When checking volume control, place scope probe on PIN EP108 and turn volume control up to see same Wavefoms as above, also check waveforms at J103 PIN1. NOTE: Check that audio cables are routed away from yoke and all IC areas when possible. |
IC208
IC302 IC207 R341 - R346 C224 Volume Control Speaker Cable. |
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