![]() ![]() The TRS3222 can be placed in the power-down mode by setting PWRDOWN low, which draws only 1 µ A from the power supply. The device operates at data signaling rates up to 250 kbit/s and a maximum of 30-V/µ s driver output slew rate. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V supply. The device meets the requirements of TIA/EIA-232-F and provides the electrical interface between an asynchronous communication controller and the serial-port connector. ![]() The TRS3222 consists of two line drivers, two line receivers, and a dual charge-pump circuit with ☑5-kV ESD protection pin to pin (serial-port connection pins, including GND). Alternative High-Speed Pin-Compatible Device (1 Mbit/s).Accepts 5-V Logic Input With 3.3-V Supply.Meets or Exceeds the Requirements of TIA/EIA-232-F and ITU v.28 Standards.CRT may get damaged, with a black burned spot inside the center of the screen. NOTE: Never switch on the set while unpluging the deflection yoke connection plug from the circuit board, without dismandling the CRT base board. Till the transistor overheats, suspect the LOT. If it doesn't overheat, suspect the deflection yoke for shorted turns of winding inside it. See whether the transistor overheats now. pull out the CRT base board out of the neck of the picture tube, place it where it doesn't get short circuited, and unplug the deflection yoke connection from the main board, and switch on the set. You can suspect the deflection yoke also for shorted winding. If it doesn't overheat, you can remove it later. You just put a small heatsink to it and check. Usually samsung sets use no heatsink for the horizontal output transistor. Replace the yoke return capacitor, 0.33uf or so also. You just replace the freewheeling capacitor, normally come up to a value of 5600pf 2000V or so, connected to the collector of the horizontal output transistor, fitted very close to the collector lead. If this frequency is found higher than normal, The main IC jungle should be suspected.Īnyway, go forward after checking this frequency. It should be around 15625HZ, with no signal. Check these three.īefore proceeding, desolder out the horizontal output transistor 2222 fro circuit, and measure the frequency at the collector point of horizontal driver transistor. The last reason for this fault is defective Line Output Transformer itsef. Even one winding get shorted, it will cause to a heavy load flyback transormer which in turn to 2222 failure. The second reason is the short in horizontal yoke windings. If this capacitor has opened of developed in value, the result will be the failure of the horizontal output transistor, at switch ON itself. Before replacing an other one, replace the freewheeling capacitor, the capcitor fitted between the collector of the 2222 and earth usually of a value of 3500pf 2000VDC, some times this value may differ from set to set. ![]()
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February 2023
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