Help identify display & buzzer

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This is the board from a discontinued alarm keypad. Everything works except that display is no longer bright enough to read and buzzer is very muffled. Like to identify and replace components. Any help or ideas appreciated.
Thanks in advance, Russ

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Hello,
Welcome to the Digikey tech forum. Do you have any markings on the individual parts you can provide or is there a schematic for the board with descriptions for these items ?

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This is from a discontinued Honeywell/Ademco alarm keypad. The company will not provide support or a replacement. So, no schematic or part numbers. Hoping to get and try generic replacement components as a last resort. I can desolder buzzer and look on inside for possible numbers there. Thought 2 line LCD was standard and could be visually identified. Thanks for any help or advise.

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Hello Russ,

Based on the age of the equipment, I assume the character display features a “Hitachi” interface. I will also assume it has a 5 VDC drive. The good news is that interface has been maintained for decades – we could almost call it an industry standard.

We would need more information to identify the part, however you may be able to locate a substitution from this list:

We will need to:

  • verify the 5 VDC rating
  • determine the number of characters e.g., 2 line 16 character
  • determine a physical size
  • verify the 16 pin connector for the new part has the same physical size

As a starting point, consider the datasheet for this specific character display:

As for the buzzer, there are two types including internally and externally driven. If I were to speculate, this is likely externally driven, which is to say, the microcontroller would send the buzzer a square wave.

You can find DigiKey’s through-hole buzzers here:

If you have an oscilloscope or multimeter with a frequency (Hz) option, you could verify the presence or absence of a square wave signal used to drive the buzzer.

Be sure to match the pin spacing so that the device will physically mount to the board.

Please let us know if we can be of further assistance.

Best Wishes,

APDahlen

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Thank you very much APDahlen !!!

This is exactly the sort of info I was looking for.
I am certain that I can now get moving in the correct direction with your info provided.

Thanks again!!!

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