York Chiller programme failure - YAEP

[tvrao]

Hi,
I have the following problem with the microprocessor board. Kindly advise if anybody has expertize about the york systems.

The unit YAEP is not functioning as microprocessor board is found faulty due to 5V regulating supply is missing from it (tested at the TPs provided). So decided to change the board with a spare available(new board has come without eprom).

After interchanging the Eprom & power-up, I find all the factory settings require reprogramming. for example starts with - Reprogram type of refrigerant to run
when I try to enter through Keypad- 22 for R22, there is no response and also the same case with all other parameters.

How I can reprogram the factory settings and what could be the problem? does it requires any code before entering?

pl suggest, thanks in advance.

[install monkey]

use the arrow buttons to select gas

[tvrao]

There are no such arrow keys provided on the keyboard. there is "+/-" key but not changing with it. I am attaching the image of keypad for understanding. anybody pl advise.