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static discharge protection in and out of circuit

Captain Stern

New member
hey, I ordered a CFAH1602B-YMI-JP.. I got it working fine, but I keep on roasting displays. I've gone through 5 so far and its getting to be a bit expensive.. I'm suspecting that static issues are the cause as the screens worked fine up until they went south.. is there some precautions I should be taking in circuit and out of circuit? I"ve got a ground strap.. even so.. I seem to have burned out another display.. I have the pinout correct. text comes up on the display. also worth noting is that the backlight and darkness of display seem to be working just fine.. also its a standard hd44780.. its using a standard test circuit I find all over the net using 100 ohm pot and 10k pot to the correct pins.. ( its the test schematic for wiring up the parrallel port).. its hooked to a 16f84a btw.
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CF Support2

Closing jumper JF to close the frame ground on the module may help your ESD issue. This will connect the bezel to the mounting hole and provide a path for the charge to go rather than through the controller. The attached image shows the back of the module and the location of JF -- jumper the first pair to connect the bezel to frame ground.


CF Tech

If you have gone through that many, my guess is that ESD cannot be the only problem. There has to be something else going on.

What kind of power supply are you using?

What kind of cabling do you have? Could things be shorting out?

Are you using a backlight current limiting resistor?

Captain Stern

New member
I am using a current limiting resistor.. just like the sample circuit called for.. I am using a 9 volt supply (commercial lab bench supply) from heald I believe.. voltage was 5 volts going into a 5 volt regulator.. but I figured that was only getting a lower voltage out.. I upped that to 8-9 volts.. all other components are working fine now. I was having issues before with some of the stuff not working.. I added a noise reducing cap into the circuit of appropriate size.. that has eliminated noise problems.. the wiring going to the display is/was working fine and is fairly clean and not oakey rigged.. used some 4 conductor wire and some cleanly stripped cat 5 wires making sure that the metal was will hidden inside the protoboard.. I've allready made this circuit on a pcb etching program and all these wires are about as solid as solid gets.. I just need to buy another display.. check all my connections for appropriate voltages etc.. everything elses works great on the board so far though..

so.. I geuss I will but another display or two.. make those mods.. jumps etc.. will these mods help static in and out of board? should I be using a anti-static ground clip with this stuff? is it really needed?

thanks for the support.

CF Support

Is there any chance that you can post your circuit?

I have to agree, going through this many displays it seems unlikely that ESD would be the only issue present.