Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

MOS power IC full range

Photocoupler

Yesterday, the mentor and the men were busy sorting out the spare parts for repairing the air conditioner in the summer. They came to a ruined acquaintance (often with his old compressor), and the car also pulled a big TV. Looking up, Hisense 34 Inch HD, produced in 2006, he asked me if I want to go, anyway, I have to go back and sell it as waste. I said that as long as the picture tube is not aging, it is basically necessary. He pats the chest to ensure that there is no aging, and that the customers who sell it are very Less watching TV, it seems that what board is broken, repairing too expensive, we lifted it off the car, unpacked the picture tube, really not aging, still very new, three 25V470UF electrolysis on the HD board Changed, the main board was also repaired a mess, 160 received, sent him away, let the disciples practice their hands.
The apprentice first checked it. The C5144 was damaged and the circuit was broken. The B+ was stable and normal. The circuit and peripheral circuits basically had traces of welding or dismantling. The line was driven by C2383-Y and the drawing was C2236. No problem with the parameters, ask the disciple to install a C5144 line tube, try to connect a 200W bulb in series to the high voltage package circuit, power on, have high voltage to produce sound, then look at the screen, the image has 10 cm on each side and no side, both sides Vertical, connected to the signal, the picture is normal (because there is a 200W bulb current limit, this phenomenon is normal), try it all at once, the image does not change, ask the apprentice to remove the light bulb, restore the circuit, boot, the picture is normal, the color is realistic, and then A down tube B pole voltage, -0.1V (mechanical meter F47 amount), is basically normal, the apprentice is happy to say so good? ? ? ? I think, it should not be so simple, let him put it a day and a half day and then happy again, really, after more than half an hour, the image of the 5 cm image on the top and bottom of the screen began to distort, the burr, the middle part is basically normal, B+ did not change, 300V is normal, The tube heat sink is slightly hot, and the tube is also heated. (At room temperature, 18 degrees, the tube is felt, the tube is heated at 45 degrees.) After more than ten minutes, "three nos", this time I dare not care, I personally went out. First carpet-type circuit and peripheral, full heating measurement, no problems found, left high voltage package and high-definition board, push the transformer normal, push the tube heat, push the transformer 12V from the power supply 15V through 20 European current limit input Normal, is it really the legendary HD board TDA9333H bad? ? ? Not reconciled, and then went up and found that the original push tube C2383 has its own push circuit, which is a composite of A1015 and C1815. It is electrolytically coupled to the base of C2383 by C42916V10UF, C429 is normal, and the equivalent is C1815, the resistance is obviously wrong. Remove the measurement, use X1K gear, quite normal, but with X1 gear, completely open, suddenly open, the original push tube also promotes insufficient heating Replace with a pair of 1015 and 1815, change the upstream tube, turn on the screen, the picture is normal, then measure the tube B pole, voltage -0.17V for 30 minutes, touch the tube micro-temperature, push the tube no longer heat, try again today, It’s all normal, I’m here to let everyone learn from it. I hope that after the majority of friends, the image will no longer be burred.
Circuit diagram: