CHUNTEX ELECTRONIC CO LTD 1769SL free download

File name 1769SL schematic.pdf

CTX 1569DSE Dead with tripping PSU CTX CPS 1560LR CTX CPS 1560LR . Line output transistor dies soon after switch-on. . Too wide and E/W fault. Line transistor becomes hot. Check IC701 (TL431), R717 (12K) and capacitor C721 (1uf 50V). If the capacitor has blown apart and the resistor burnt, check the line output transformer before replacing any components as in my monitor the transformer had literally melted at one side and a crack surrounded the transformer's middle. Obviously this transformer had developed a EHT to pin 11 short with catastrophic results. Replacement transformers are available but due to the cost it is usually more economical to scrap the monitor. [HV is present for a short while; 250V at collector if it is de-soldered, also when load is applied with a lamp]. Check downward control/PSU, add 200R to the Ub-supply to the line transformer if necessary. Check diodes and drive control transistor(s) in the width control. Overheating of the line transistor may be due to the line amplitude being too high. Check ZD101 (18Vdc) in power supply on left near front on main board edge, Q101 (92SK955-2SK956) on black heatsink in power supply, R114 (39R/2W 5%), IC101 (UC3842 - NTE7096J) and R113 (100R/0.25W 2%)on power supply's small daughter board, C113 (0.01uF/50Vdc) on daughter board, fuse (2.5A) on left edge of main board. Solder power supply's small daughter board connections at main board. Q101 (K118), D102, R104 (0R25/1W), F101 (Gma 3.15A). Squealing]. D108 (Bym26c), D410 (5thz52), Q402 (A953), R441 (2R2/0.5W), C407 (432j-pp630). Q103 (2SC3457), Q401 (2SC3886A) Check IC101 (UC3842AN), C112 (100/25). Check D108 (BYM26C), D410 (5THZ52), Q402 (A953), R441 (2.2-0.5W), C407 (432JPp630). Replace C123 (10uF/250V) and C427 (1uF/200V). Check C601, C602 and C603 on CRT board. Replace C431 (10uF/250V). Replace C427 (1uF/200V). IC402(LM317) and R449 bad solder joint. Replace C427 (1uF/200V). Check diodes and drive control transistor(s) in the width control. Overheating of the line transistor may be due to the line amplitude being too high. IC203 (C4557C). Clean pot VR407. Q408 (Ytf630). Resolder area including width pot VR401 and capacitor on the back of the board connected to it. Also resolder L406. Check Q408 (YTF630). Resolder area including width pot VR401 and L406. DBLCPS1560 CRT size: 15" SVGA. CTX CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR CPS 1560LR Dead. Dead. Dead. . Power cycles. Shakes. Takes approx 15 mins to power up. . Dead. Squealing. Dim picture. Vertical size expanded. Squigly text. . Uneven colour; virtually green. . Intermittent pincushioning. . Pincushion when warm. E/W failure. Frequency switch does not work. . E/W error. . Too wide and E/W fault. Line transistor becomes hot. . Horizontal width and pincushion cannot be adjusted correctly. . Problems with the pincushion, re