I wasn't exactly sure where this belonged in the forums, I guess it's technically electronics theory and general function, hoping someone with microcontroller knowledge can help me out.
I have two boards(a 10 year old one and a new one) with two different types of 4 digit 7 segment LED Displays on them. For one reason or another, the segments on the displays eventually dim, go out, or the displays stop functioning entirely. The company that makes the boards will not replace the display only, the only thing they will do is replace the entire board for about $600 which is absolutely ridiculous.
So the tinkerer in me starts thinking that there has to be a cheap replacement for these displays. Here's where it gets interesting, if anyone is interested enough to help me out with this read on, it would be GREATLY appreciated!!!
For the remainder of this post I will be referring to the old board as REV. A and the new board as REV. C. My journey started with me simply trying to find the same display used on the REV. A board. After combing through the internet in it's entirety, I was able to find the datasheet to this display. It's made by a company called THREE-FIVE Systems, a company that went bankrupt 10 years ago. http://www.farnell.com/datasheets/31648.pdf
After calling many electronics manufacturers in the U.S. and abroad, it became apparent that it's absolutely impossible to get a hold of these dated displays. So I thought no problem, I'll simply use a new display in the old board, surely I'll be able to find one!
It turns out that the new displays are custom fabricated by the company that makes the boards.
I wasn't about to let that stop me, so I created an exact replica of the new display using the ole' iron and toner method, transferred the components onto my board and viola! I now have a functioning board of my own.
So if anyone is still awake after this tall tale, here is where my problem lies.
My homemade display obviously functions perfectly in the newer REV. C board, but shows no signs of life in the older REV. A board.
This is where my knowledge ends, and where I need the expertise of you fine gentlemen.
The two boards look *almost* identical, with the main differences being a micromonitor chip and a quartz crystal on the old board, and the boards having different microcontrollers.
All of the voltages going to these components are exactly the same, which is why I'm having trouble understanding why the newer display doesn't function in the old board.
I've included pictures of all these components as well as the datasheets for the microcontroller on the REV. A board(http://pdf1.alldatasheet.com/datashe...C751-4N24.html), the microcontroller on the REV. C board(http://www.nxp.com/documents/data_sheet/87LPC762.pdf), and the driver IC chip found on the new display(http://pdf1.alldatasheet.com/datashe...TB62709NG.html.
My goal is to be able to either use the microcontroller from the new board in the old board or modify the old board to accept the new display.
I realize that this post is way too long and drawn out, I'm just hoping there's a fellow techie out there who can help!
the two boards side by side:
the other side of REV. C:
the other side of REV. A:
the two display boards side by side(the REV. C is on the left, REV. A on the right):
I have two boards(a 10 year old one and a new one) with two different types of 4 digit 7 segment LED Displays on them. For one reason or another, the segments on the displays eventually dim, go out, or the displays stop functioning entirely. The company that makes the boards will not replace the display only, the only thing they will do is replace the entire board for about $600 which is absolutely ridiculous.
So the tinkerer in me starts thinking that there has to be a cheap replacement for these displays. Here's where it gets interesting, if anyone is interested enough to help me out with this read on, it would be GREATLY appreciated!!!
For the remainder of this post I will be referring to the old board as REV. A and the new board as REV. C. My journey started with me simply trying to find the same display used on the REV. A board. After combing through the internet in it's entirety, I was able to find the datasheet to this display. It's made by a company called THREE-FIVE Systems, a company that went bankrupt 10 years ago. http://www.farnell.com/datasheets/31648.pdf
After calling many electronics manufacturers in the U.S. and abroad, it became apparent that it's absolutely impossible to get a hold of these dated displays. So I thought no problem, I'll simply use a new display in the old board, surely I'll be able to find one!
It turns out that the new displays are custom fabricated by the company that makes the boards.
I wasn't about to let that stop me, so I created an exact replica of the new display using the ole' iron and toner method, transferred the components onto my board and viola! I now have a functioning board of my own.
So if anyone is still awake after this tall tale, here is where my problem lies.
My homemade display obviously functions perfectly in the newer REV. C board, but shows no signs of life in the older REV. A board.
This is where my knowledge ends, and where I need the expertise of you fine gentlemen.
The two boards look *almost* identical, with the main differences being a micromonitor chip and a quartz crystal on the old board, and the boards having different microcontrollers.
All of the voltages going to these components are exactly the same, which is why I'm having trouble understanding why the newer display doesn't function in the old board.
I've included pictures of all these components as well as the datasheets for the microcontroller on the REV. A board(http://pdf1.alldatasheet.com/datashe...C751-4N24.html), the microcontroller on the REV. C board(http://www.nxp.com/documents/data_sheet/87LPC762.pdf), and the driver IC chip found on the new display(http://pdf1.alldatasheet.com/datashe...TB62709NG.html.
My goal is to be able to either use the microcontroller from the new board in the old board or modify the old board to accept the new display.
I realize that this post is way too long and drawn out, I'm just hoping there's a fellow techie out there who can help!
the two boards side by side:
the other side of REV. C:
the other side of REV. A:
the two display boards side by side(the REV. C is on the left, REV. A on the right):
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