Dell D1626HT - UltraScan 1600HS - 21" CRT Display Service Manual

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Dell D1626HT - UltraScan 1600HS - 21" CRT Display Service Manual Manual pdf 19 page image

SECTION 4ADJUSTMENTS• Landing Rough Adjustment1. Enter the full white signal. (or the full black dots signal).2. Adjust the contrast to the maximum.3. Make the screen monogreen.Note: Off the outputs from R ch and B ch of SG.4. Reverse the DY, and adjust coarsely the purity magnet so thata green raster positions in the center of screen.5. Adjust the tilt of DY, and fix lightly with a clamp.Note: “TILT” shall be set at 0.• Landing Fine Adjustment1. Put the set inside the Helmholtz coil. (“LCC SW” = “12”)2. Input the single green signal and set the CONT control toMAX.Note: After the W/B adjustment with 9300K, measure an averageof ΣIk when a full white signal is entered in the CONTMAX/BRT CENT status. Then make adjustment so that thespecified screen can be attained after aging for 2 hours withIk equivalent to 30% of the average value.3. Demagnetize the metal part of the chassis with the hand de-gausser and coil degausser, and the CRT surface with thehand degausser.Input AC 230V to AC IN, turn on and off the power to per-form auto degaussing. (Perform auto degaussing by setting“MON CON REG2”=152. Return to the original value afteruse.)Demagnetize the CRT surface with the hand degausser again.Note:(1) Hand degauss must be used on stand-by or power-off condi-tion.This model has an automatic earth magnetism correctionfunction by using an earth magnetism sensor and a LCC coil.When using a hand degauss while monitor (LCC coil) is beingoperated, it sometimes gets magnetized, and the system maynot work properly as a result.(2) Adjust in a non-magnetic field. BV=45uT.(3) If adjusting in a magnetic fields, add the shift from the non-magnetic field in your estimation.4. Attach the wobbling coil to the designated part of the CRTneck.5. Attach the sensor of the landing adjustment unit on the CRTsurface.6. Adjust the DY position and purity, and the DY tilt, and land-ing of the center and 4 corners with the landing checker.After adjustment, set “LCC SW” to “13”.• Write terrestrial magnetism sensor reading VX and VY to“LCC VX” and LCC VY” respectively. Adjust the landingby moving “LCC NS”, “LCC LT”, “LCC LB”, “LCC RT”and “LCC RB”. However, the register adjustment must belimited within the following range.“LCC NS” 128 ± 15“LCC LT”, “LCC LB”, “LCC RT”, “LCC RB”128 ± 40Save the service data.A difference between red and bluemust be within the specificationgiven right.* Adjustment and measurement should be made at the points oneinch inside the fluorescent screen.± 6 ± 6 ± 6± 6 ± 4 ± 6± 6 ± 6 ± 6Adjust so that the green is withinthe specification given right.4 corner adjust target : within ± 1The red and blue must be withinthe specification given right withrespect to the green.0 ± 3 0 ± 7.5 0 ± 30 ± 5 0 ± 5 0 ± 50 ± 3 0 ± 7.5 0 ± 3(μm)(μm)10 10 1010 7 1010 10 10(μm)7. For the up/down swing, swing the DY and insert a wedge sothat the up and down pins are equal at the top and bottom.Adjust the DY TLV VR so that the horizontal trapezoid isequal at the left and right. Insert the wedge firmly so that theDY does not shake.8. Check the landing of each corner, and if it does not satisfy thespecification, adjust the landing of four corners using “LCCLT“, “LCC LB”, “LCC RT” and “LCC RB”.However, the register adjustment must be limited within thefollowing range.“LCC NS” 128 ± 15“LCC LT”, “LCC LB”, “LCC RT”, “LCC RB” 128 ± 40After adjustment, save the service data.9. Remove the sensor and wobbling coil.10. Switch the signal to R.G.B., and check that each color is pure.11. Check that the DY is not tilting.