i don't have any specific information on mobil equipment but i may can help.
If you can get the information off the controller data tag, brand, model number if any.
As for that flashing light on the controller?
if it is flashing a slow pulse every few seconds then that just indicates it is powered on and that slow pulse is normal.
Now if there is an error it should flash the error code with quicker pulses.
It would flash the first digit, then pause and flash the second digit etc.
most error codes are 2 digits for drive errors and 3 digits for hydraulic errors.
Lets say it has a drive system error and the code is E48, the light would flash four times in like 1 second succession, then pause for a couple seconds, then flash 8 times. It will continue to flash this code until it is resolved. If a hydraulic code just watch for a 3rd set of flashes.
Once it flashes all the active codes it will pause for a bit and then roll them out again starting with the first code you saw and so forth.

If you can get the information off the controller i have some info on most controllers and can help you figure out whats wrong.