Intermittent no power was the complaint of this Epson lx 300 printer. As usual, the main suspect was the ability on/off switch. After removing the power board from the printer, I could clearly see a dry joint in the pin of the switch mode power transformer. This was the caused for this printer problem. There no other loose connection or dry joints on one other part.
Cleaning with the thinner solution and applied fresh solder solved the intermittent no power problem. In this article, I are looking you to know not all power problems must be caused by major components burnt. A loose connections, dry joints, resistor open circuit, high esr ohms in electrolytic capacitor could cause intermittent no power or no power at all.
Troubleshooting with greatest techniques and using a good procedure would normally solve electronic faults easily. Yet another thing that I to be able to share with you is that the ability board is using a dual photo coupler (optoisolator) NEC PS2561-2 ic. There are two separate optoisolator ic built into one single policy. If you have the ECG Philips master replacement guide book, may potentially find out the interior diagram of this kind of of ic. Possess locate the pinouts, you actually could test it along analog multimeter. About how precisely precisely to test optoisolator, you could refer back to my website.
Sometimes there will than few problems that you need to repair. In the above case, after power over the printer, it can't print at practically. It looks like there was not signal entering the CPU IC. The printer self test works perfectly yes. For your information, if this of problems happens in other brand of printer, the troubleshooting method is issue. I will first the the communication chip or buffer daphnie. In this printer, the main suspect was the Maxim Max232cwe multi channel RS232 Transceivers ic.
Solder the ic out was actually problem in this smd type ed. After the replacement with model new ic the printer works beautifully. Remember, whether you are troubleshooting the Epson lx 300 printer or any other model, first examine the printer cable and after which the communication or buffer ic.