Different possibilities. Most likely assembly problem.
Check continuity of LCD lines. Check x-tal en caps. Make sure LCD and controller get +5VDC. Inspect all controller lines. If you suspect controller (unlikely but possible), return it for inspection/exchange.
i’ve got the same problem but my 8045 worked well. Since yesterday, i only see the 8 aquares on the left side.
The EEPROM is working, I tested it, i also tested the power supply, there are 5VDC everywhere.
So I’ve got some devices to test Elements of the device like Multimeter, Oscilloscope etc.
I’m not sure whether display or controller causes the problem.
Is it possible to give some advice what to do?
Sorry for my english - i’m a german… :?
[edit]
I testet a little bit:
On switching on the Devide, the display shows " ? ? ?/?". Maybe this would help you.
[edit2]
If both DIP-switches are off, the display shows the number 1 to 8. But the numbers are scrolling, i’ll try to discribe it: The number begins dark at the top, at the bottom. Then iht “rolls” down and begins at the top again.
Okay, it is the display.
I used google and found a website, discribing how to connect such a display to the parallel port. On Parrallelport (tested with LCDHype) it’s the same problem.
If the problem is not caused by an assembly mistake or defective component, it can be caused by an etching error on the PCB (two tracks touching when they should not).
Inspect the PCB with a magnifier, especially the x-tal tracks.
[quote=“VEL417”]If the problem is not caused by an assembly mistake or defective component, it can be caused by an etching error on the PCB (two tracks touching when they should not).
Inspect the PCB with a magnifier, especially the x-tal tracks.[/quote]
Many thanks.
It´s working it was a shortcut in the place that you told me.
But a short on the board, betwen the 1st point and the next track.