Basic Table Troubleshooting

Modified on Fri, 3 Jan, 2020 at 12:17 PM

Tables
- Electrical
  - Batteries not charging
    - Ensure proper input voltage
    - Perform a load test on batteries
    - Test capacitor rectifier unit (see specific maintenance manual for procedures)
    - Check all connections
    - Possible relay box issue
    - Table not turning on
    - Check table fuses
    - Ensure proper input voltage
    - Ensure thermal relay is not tripped (inside pump on some models)
    - Check voltage on backside of receptacle while switch is in on position.
  - Table powers on but does not function
    - If battery table switch operating modes if function works it eliminates pendant
    - Check emergency stop (if applicable)
    - Check circuit breaker (some models)
    - Check wiring to relay box and to pendant control
    - Listen for firing solenoids, if they are firing test pump motor
    - If no solenoids are firing but there are relays clicking check connections from relay box to solenoids
    - If pendant is analog test pendant per maintenance manual
  - A specific function does not work
    - If battery table switch operating modes, if function works eliminate pendant
    - Ensure there are no inhibit switches causing the issue
    - Under base cover listen for solenoid on mini valve to activate if it does not perform an Ohms test on the affected function. Readings should be between 16-20 ohms on a battery table or 60-90 ohms on a line power table.
    - If solenoid is good disconnect connector going to mini valve assemble and activate affected function, if you hear relay in box function then pendant is good.
    - Check for hydraulic issue (see hydraulic troubleshooting)
    - Relay box issue
- Mechanical
  - Table making noises while functioning
    - Try to pin point where it is coming from
    - If back or legs remove pins, clean and re-grease.
    - Remove cam pins clean and re grease
    - Check clearance between cylinder and casting
  - If noise is present under seat section remove seat and hose cover, clean and re grease hoses
    - If noise still present under seat rerouting/zip tying may be required
  - If suction noise in base check oil level
  - Head section double clicking
    - Ensure that knobs are fully tight and that head section is fully pushed in.
    - Ensure that head section rods are not bent (note new head section rods do not come pre drilled)
    - Ensure frame is not bent
    - Adjust using Allen bolts and set screws
    - Eliminate double click and ensure levelness of head section
  - Elevation not working correctly (stuck or chatters) on round column
    - Ensure all electrical and hydraulic functions are in working order
    - If chattering lube very liberally, function up and down repeat until slider grease (molykote part # D6-010-89)
    - If lubrication doesn’t fix chattering loosen keys starting with top. Unlock table top. Swing around hold table firmly against stop and tighten key. Reverse table top and repeat above process
    - If adjusting keys doesn’t work replace keys
    - If replacing keys doesn’t work replace slider
    - If round column is completely stuck it could be hydro locked from excessive grease mixed with hydraulic oil. It could also be locked up from lack of maintenance, or too little grease.
    - If unable to be freed contact a Skytron representative. If freed determine if hydro locking or neglect was the cause.
    - If hydro locking was the case clean off grease / oil and re grease.
    - If neglected/lack of maintenance see above instructions pertaining to chattering
  - Elevation not working correctly (stuck or grinding) old style square column with flat plastic bearings.
    - Check to make sure stop pin (on side of slider) is not over tight or rubbing on inside piece of slider
    - Adjust bearing tension per instructions in manual
    - After freed inspect inner and outer bearings and races for damage
    - If grinding check bearings and races and replace as necessary
    - Elevation not working correctly (stuck, non-fluid motion or making noise)
    - Check to make sure stop pin (on side of slider) is not over tightened hitting the slider making noise or stopping it completely
    - If frozen or making noise look at bearings or in bottom of base for tiny ball bearings (look like BB’s)
    - If ball bearings present replace damaged bearings.
    - If no evident damage use grease fittings and high pressure grease to lubricate bearings. If no fittings just lube up rails and function up and down
Hydraulic
- Function drifting
  - On old tables If you can tap the table down for a second and table keeps drifting down even slightly recommend rebuilding mini valve assembly (works with other functions too just more prominent on table down)
  - On new tables remove check valve and inspect for damage even the slightest nick could cause drifting. Also inspect side of valve for wear marks.
  - If valves are good trace hoses and look for leak
  - Likely internal leak in cylinder if no external leaks found
  - Function doesn’t function all the way or part of the way
  - Check fluid level
  - Ensure this isn’t a micro switch issue
  - Could be a mechanical issue also (something bound enough to cause pressure relief valve to activate)
  - Possible air in the system recommend turning speed controls all the way up and then functioning (if kidney recommend bleeding cylinder)
  - If none of above work check table pressure (if unable to adjust PRV to correct setting recommend replacing)
  - Inspect mini valve check valve
  - Recommend rebuilding cylinder
- No table function
  - Ensure no electrical issue
  - Do a pump motor test
  - Remove output line from pump and check to see if oil comes out when pump is functioned, if it doesn’t check for broken pump gear. If there is oil present check pressure relief valve is most likely cause.
  - Any user error issues with tables are typically crashing the table into itself or the ground. There is a safety information section at the beginning of every owner’s manual.