Looking for help on Hew Holland TN 55 rear lift

[DC0046]

Father has a TN 55 and never used the lift o'matic. Decided today to get it working. The lift operating lever was working perfectly before adjusting the height adjustment on the lift o'matic. I also had to adjust the cable that controls the lift o'matic. It was working fine with both the lower and upper setting and suddenly, we were unable to set the lowered height of the implement. Now, the lift lever will not raise or lower the implement. I have tried will the lift o'matic in both the raise and lowering position. The only way to raise the implement now is with the lift o'matic AND there is no lower adjustment.

Would really appreciate any suggestions to get this resolved. Have a lot of pasture to get clipped.

Thanks!!