Ray,
get a hydraulic guage and connect it to the test ports on the pump's and check the pressure when trying to operate functions and see if there are any pressure readings at the pumps.
There also may be a pressure test port on the boom inline with the hoses at a standoff for the hose supports at the access area in the side of the boom arm. Also may be a port on the control valve itself.
pump pressure should read around 2600 psi on boom raise and extend relief.
carriage up/down relief should read around 2400psi.
outrigger relief should read 2600psi.
steering relief should read around 1800 - 2000 psi depending on serial number break (year it was built).
if your still reading no pressure at those test ports i would check the hydraulic filter and oil level first. replace the filter(s) it may have 2 mounted. It probably has a guage mounted on the return filter with a red/yellow/green range and make sure it is in the green.

just a couple of things to look at for now

Carlos,
try recalibrating the joystick again

sorry to bother you having trouble using this site , I have a 1999 lull 844c-42 with a john deer 4045t engine lost all hydraulic pressure of checked all the usal suspects being check valves and reliefs cant find anything wrong is it possible pumps failed causing inital pressure failure not allowing activation to my knowledge pumps are there to create flow not pressure reason i ask is i have no pressure reading at test ports or from pump witch i believe to be bad, i have also blocked off spool assemblie to see if pressure would build seems to dead head from flow but still no pressure rise i also pulled pumps from transmmision to check shafts and couplings nothing wrong there as well any info would be appreciated

Hi. The joystick card has already been changed, but now the new fault code presented by the lower control is 202, can you help me solve this problem?

first try this
cycle the power on and off 5 times
wait 10 seconds between each cycle of the power, see if codes clear after doing this.
If not then there may be a problem with the wiring in the harness to the platform control module. Check the connector where it plugs into the truck side and also the platform control module side.
These connectors do plug in and have a lock ring that has to be twisted to lock the connector into the plug so make sure it is completely inserted and locked into the connector properly.

If the cable and connectors check out ok visually and are connected properly then follow this procedure:

Manual suggests to remove the 9 pin platform control module connector from the side of the platform junction box and the P4 connector at the ground control module. Check continuity from the P4 connector, pin5 to junction box pin3 and P4, pin9 to junction box pin4. Is there continuity on these wires?
If no continuity repair wiring
If continuity then replace control module.