No display on Sam4s ER-265

Hi,

There is no separate fuse that solely supplies the power to the screen. The power is derived from the main power supply in the cash register and the correct voltage is supplied to the screen circuits.

Is the screen backlighting on at all (screen brightens) and it is just that there are no images being displayed or does it stay totally blank?

If it stays totally blank then there may be a problem with the screen’s backlighting. Either the power is not being supplied to the screen due to a problem with the backlight power supply, the harness connection between the circuit board and the screen or there is a problem in the screen itself.

If the screen “lights up” but there is no information or images being displayed then there is a data problem between the control board and the screen, perhaps in the harness connection or again it may be in the screen

I couldn’t find a service manual for the 265 but here’s a link to the SAM4s ER-260 series service manual, which hopefully may be of some help.

It has full schematic diagrams, troubleshooting flowcharts, a parts list and the dis-assembly procedures so that you can diagnose what the problem is and hopefully rectify the problem.

You will need to know how to read electronics circuit diagrams. If the problem is no backlighting, start with the section describing PFAIL (see p.5-3 in manual) and see if that helps as this relates to the backlight power supply.

If this seems too daunting, contact a reputable, professional electronics repair service and ask for a quote to repair the cash register.