Epson PX8 Printer Problem.

[JohnBHanson]

I have an epson PX8 that has died. I have checked the voltage rails and also the CPU clocks and they appear in order, address and data lines are moving.

When I power it on it does not display anything on the lcd screen, but the CAPS lock light comes on sometimes.

Any ideas?

[SiriusHardware]

Originally Posted by JohnBHanson

I have an epson PX8 that has died. I have checked the voltage rails and also the CPU clocks and they appear in order, address and data lines are moving.

When I power it on it does not display anything on the lcd screen, but the CAPS lock light comes on sometimes.

Any ideas?

I don't know the machine personally, but it sounds as though everything may be working bar the display.

Unlike modern alphanumeric LCD displays, first generation LCDs often needed a negative bias voltage for the contrast circuit, with the -Ve supply possibly generated by a dedicated negative output from the main PSU, or an ICL7660 voltage inverter IC, or a switched-mode power supply using a general purpose switchmode IC or a discrete oscillator circuit. Could this be your problem?

(By the way, did you really mean 'printer' in your subject heading? Or did you mean 'computer'? I know that there was actually a printer for the PX8 but I've never seen one with a caps lock light).