Bomag BW177 DH-40 Stuck in Park?

[DGODGR]

I have the above mentioned 66" wide single drum roller. While my operator was running it (performing a compaction cycle) the roller suddenly stopped rolling. It would try to go forward and backward (the lever would move in either direction, and the motor and trans would bog against resistance) but would not move. Is this a possible micro-switch issue? Should I be looking at the "panic button" by the F/R lever or is there another one under the panel for the parking detent of the F/R lever? It should be noted that we were compacting cobbles (hammer breakings) with a fill layer that reduced thickness because the underlying bedrock layer was sloped. If the operator wasn't careful, once the layer got shallow enough, the roller was attempting to compact rocks on top of bedrock. This obviously puts a lot of energy back at the roller causing some serious vibration (machine actually bounces), which I certainly has the possibility to shake/damage some things.
I would also love to hear about how I can tow this unit (in the event that I can't get it fixed quickly) as it is currently preventing us from performing any work since it's broke down n a "bottleneck" location.

Thanks!

 

[Vetech63]

Ive seen serious vibration allow the microswitch blocks on the bottom of the park brake switch to rattle loose and fall away from the switch itself.

 

[mg2361]

Serial number?

 

[Redbirds13]

Check your coil on the park brake valve…from there make sure your proximity switches under the lever are good

 

[DGODGR]

It's been a while on this one. I just saw the above reply but I hadn't seen ten previous ones. I want to apologize to Vetech63 and mg2361 for the lack of response when you offered your help.

It turned out to be the micro switch on the dash (the red "panic" button). We were able to get he machine to operate by pulling up on, and twisting said micro switch. This validated my suspicions. I have a new switch in hand but, so far, we have been able to keep it running with the original one in there. On the rare occasion that it won't drive (similar symptoms as I stated in the original post) we simply lift and twist the switch and it works.