SK40C + LCD help!!

[Brian Griffin]

Eyes can be deceiving sometimes. Remove power for SK40C. With the LCD plugged in, set the ohmmeter to X1 range (analog) or buzzer mode (digital). Measure pin 1 against pin 2 then pin2 against pin3 and so on .... until pin 16. If you see the meter swing to zero or the buzzer buzzes, then you'll know what I mean.

Allen

If the LCD is plugged in, where am I taking the measurement from? The only exposed metal is the solder.

This is called "Continuity Test". When the multimeter buzzes, that means it is a short circuit.

[chaos64]

Our multimeter has no buzzer, but when taking the measurements it was approximately 12.5K ohms between Vdd and GND and approximately 12 M ohms between Vdd and CON pin. All other measurements gave us 0 on the multimeter. What does this mean?

[ABSF]

All other measurements gave us 0 on the multimeter. What does this mean?

Does "All other measurements gave us 0 on the multimeter." refers to the test as metioned by Idris and myself? If that is the case , you need to ask someone who knows how to solder to redo the soldering for you.

Allen

[robosang]

We soldered the female header to the board so we can plug the LCD into it easily instead of soldering it directly to the board.

Is that female header? Looks to me like Turn Pin. Can you really plug the LCD with the header pin into turn pin nicely? I doubt that! Despite the soldering "short", I don think the connection can work

I would agreed with Allen, please look for someone to solder properly for you.

[Brian Griffin]

I couldn't see the photo clearly.

If the LCD's plugged on the turn-pin headers beside the chip, it probably wouldn't work for sure.

I thought there's an LCD header on those Cytron SK40C boards? Why not use that one?

[ABSF]

I think he did plugged in correctly. Only thing is that the pins would be to tight to go in completely and some pins might be not making proper contact...

The LCD is mounted correctly

Allen

[chaos64]

Okay since we thought at first it was the soldering on the LCD that was our problem, my friend took it to try and fix, but now since I realize this header we used is the wrong type, my first question is:

1. If I plug the LCD pins into a breadboard and use jumpers to connect to the Turn-Pin header, will that make sufficient contact to communicate properly to my LCD assuming the soldering job on the LCD pins is good enough? and

2. Should I try and de-solder the Turn-Pin header from the board and solder the LCD pins directly in its place on the SK40C?

I'm still not sure why this header would not work fine with the LCD pins, it plugged in fine but the pins didn't seem to go in all the way, I suppose that's the issue? I mean it plugged in fine meaning that it isn't difficult to insert or take out, it just seemed to not go in deep enough. The LCD backlight pin always worked, if the LCD backlight jumper on the SK40C board was plugged in using a jumper, the LCD backlight was always on when the board is powered. This is with the LCD plugged into the Turn-Pin header that you all believe is the cause of my problem. So before I try and desolder this Turn-Pin header, I'd like to know why the backlight pin and obviously Vdd worked as well since the backlight is good work but communicating to the LCD didn't work with the sample program. Please help.

[robosang]

If you are not good in soldering, please don de-solder Because de-solder something is harder than solder something

Why the LCD back light always work and the communication cannot work? LCD backlight is only 2 pins, communication? at least 10 pins, should be more, miss one connection, fail! And frankly, we are not sure the problem is due to connection, PIC? power? program? LCD? or other. But we are trying to minimize the possible root-cause and one of it is wiring. The connection that you show us do not convince us it can offer good connection.

[chaos64]

So what should I do about having the wrong header on the LCD interface of the SK40C? Am I forced to leave it there and try and wire up the LCD through a breadboard with jumpers connecting the header and LCD? That seems like my best solution right now, my friend brought the LCD to work to try and fix, but like I said in my early post, the multimeter said 0 ohms on most connections on the LCD, and 12k ohms between 2 of the pins and something in the MEG ohm range between another two. What do these results even mean? That the two readings with resistance are bad or are they the only good connections?

[ABSF]

Two options:

1. Leave it like that but you need to remove the excessive solder using this
http://www.cytron.com.my/viewProduct.ph ... ing%20Pump
Then stick to your plan using a breadboard as the connecting bridge.

2. Get someone who has the skill to do soldering to unsolder it for you then install the correct female headers.
They are actually quite simple and shouldn't have make you so upset...

*3 Buy a new SK40C if that doesnt make you broke. ..........Just kidding

Allen