Epson LX300 Printer Repair-No Power
and Can't Print Caused By A Faulty
Max232cwe Ic
Intermittent no power was the complaint of this Epson lx 300 printer. As usual, the
main suspect was the power on/off switch. After removing the power board from the
printer, I could clearly see a dry joint at the pin of the switch mode power transformer.
This was the caused of the printer problem. There was no other loose connection or
dry joints on the other part.
Cleaning with the thinner solution and applied fresh solder solved the intermittent no
power problem. In this article, I would like you to know that 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 the right
techniques and using a good procedure
would normally solve electronic faults
easily. Another thing that I want to
share with you is that the power board
is using a dual photo coupler
(optoisolator) NEC PS2561-2 ic. There
are two separate optoisolator ic built
into one single package. If you have the
ECG Philips master replacement guide
book, you could find out the internal diagram of this type of ic. Once you locate the
pinouts, you actually could test it with your analog multimeter. About how to test
optoisolator, you could refer back to my website.
Sometimes there are more than few problems that you need to repair. In the above
case, after power up the printer, it can’t print at all. It looks like there was no signal
entering the CPU IC. The printer self test works perfectly okay. For your information,
if this type of problems happens in other brand of printer, the troubleshooting method
is the same. I will first look at the communication chip or buffer chip. In this printer,
the main suspect was the Maxim Max232cwe multi channel RS232 Transceivers ic.
Solder the ic out was not a problem in this smd type ic. After the replacement with a
new ic the printer works beautifully. Remember, whether you are troubleshooting the
Epson lx 300 printer or any other model, first check the printer cable and then the
communication or buffer ic.
The MAXIM MAX232CWE IC