Power examination tables

Midmark 411: troubleshooting and error codes

The ServiceForge knowledge base holds 24 documented symptoms for the Midmark 411, with 78 ranked causes, 20 diagnostic checks with test points and expected values, and 0 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Foot up and down functions do not work

FOOT UP and FOOT DOWN buttons pressed but table does not move; all other functions operate normally

Ranked causes

1. Pan holder assembly not fully inserted; pan safety limit switch not tripped (common)
2. Foot capacitor weak or blown (common)
3. Thermal overload switch in foot actuator activated (common)
4. 5 amp FOOT fuse blown on interface board (common)
5. Foot actuator assembly malfunctioning (occasional)
6. Wire connections loose (common)
7. Pan safety switch out of adjustment (occasional)
8. Pan safety limit switch malfunctioning (occasional)
9. Interface board malfunctioning (occasional)

First check

Check that pan holder assembly is fully inserted

Test point: Pan holder assembly position
Expected: Pan holder fully pushed in

3 more checks with pass and fail actions, 9 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table does not operate caution

When any hand control or console button is pressed (up/down/auto-return/programmed position), nothing happens - actuator motor does not run or hum

Ranked causes

1. Power cord not plugged into facility wall outlet (common)
2. CONTROL PANEL POWER switch is OFF (common)
3. Facility circuit breaker providing power to table is tripped (common)
4. Wire connections loose (occasional)
5. 0.15 amp transformer primary fuse on interface board is blown (occasional)
6. Interface board is malfunctioning (occasional)
7. PC logic board is malfunctioning (occasional)

First check

Verify power cord is plugged in

Test point: facility wall outlet
Expected: power cord connected

2 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

BACK UP and BACK DOWN functions do not work caution

When BACK UP and BACK DOWN buttons are pressed, table will not move; all other functions work

Ranked causes

1. BACK capacitor is weak or blown (common)
2. Thermal overload switch in back actuator is activated (occasional)
3. 5 amp BACK fuse is blown (occasional)
4. Back actuator assembly is malfunctioning (occasional)
5. Wire connections loose to back actuator (occasional)
6. Interface board is malfunctioning (rare)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table up and down functions do not work

TABLE UP and TABLE DOWN buttons pressed but table does not move; all other functions operate normally

Ranked causes

1. Base capacitor weak or blown (common)
2. Thermal overload switch in base actuator activated (common)
3. 5 amp TABLE fuse blown on interface board (common)
4. Base actuator assembly malfunctioning (occasional)
5. Wire connections loose (common)
6. Interface board malfunctioning (occasional)

First check

Perform continuity check on 5 amp TABLE fuse

Test point: 5 amp TABLE fuse on interface board
Expected: Continuity present (not blown)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

TILT UP and TILT DOWN functions do not work caution

When TILT UP and TILT DOWN buttons are pressed, table will not move; all other functions work

Ranked causes

1. Tilt capacitor is weak or blown (common)
2. Thermal overload switch in tilt actuator is activated (occasional)
3. 5 amp TILT fuse is blown (occasional)
4. Tilt actuator assembly is malfunctioning (occasional)
5. Wire connections loose to tilt actuator (occasional)
6. Interface board is malfunctioning (rare)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Programming function does not work

Table position cannot be programmed into memory; when PROGRAMMED POSITION button is pressed, table does not move to proper stored position

Ranked causes

1. Receiver and transmitter not aligned or malfunctioning; signal lost (common)
2. RF cables shorted or open (occasional)
3. Program panel malfunctioning; switch membrane malfunctioning (occasional)
4. Program panel interface board malfunctioning (occasional)
5. PC logic board malfunctioning (occasional)

First check

Check L.E.D. on PC logic board for function (D1-Base, D2-Foot, D3-Back, D4-Tilt)

Test point: L.E.D. on PC logic board
Expected: L.E.D. not illuminated

1 more check with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table moves fine for light patient but slowly or not for heavy patient patient safety

Table operates normally with light patients but will not move or moves slowly with very heavy patients

Ranked causes

1. Low voltage supplied to table (common)
2. Gas spring weak (common)
3. Table overloaded with patient exceeding weight capacity (common)
4. Capacitor for suspect function weak (occasional)

First check

Check voltage at wall receptacle

Test point: Wall receptacle
Expected: 115 +/- 5 VAC, +/- 5 VAC
Tools: Multimeter

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Auto return function does not work

When AUTO RETURN START button is pressed, nothing happens

Ranked causes

1. Program panel malfunctioning; switch membrane malfunctioning (occasional)
2. Program panel interface board malfunctioning (occasional)
3. Base down limit switch malfunctioning; stuck open (occasional)

First check

Perform continuity check on base down limit switch

Test point: Base down limit switch
Expected: Closed

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Back up or down function does not work asymmetrically

One of back up/down functions operates properly but the other does not; all other functions work

Ranked causes

1. Wire connections loose to back actuator assembly (common)
2. Interface board malfunctioning; relay for up or down function malfunctioning (occasional)
3. Back actuator assembly malfunctioning (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Excessive sideways play of table top patient safety

Table top is not stable and can be moved from side to side

Ranked causes

1. Chain assemblies loose (common)
2. Base slide assembly worn or deformed (occasional)
3. Table base not resting firmly on floor (common)

First check

Check tension of chain assemblies

Test point: Chain assemblies
Expected: Proper tension

1 more check with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Foot up or down function does not work asymmetrically

One of foot up/down functions operates properly but the other does not; all other functions work

Ranked causes

1. Wire connections loose to foot actuator assembly (common)
2. Interface board malfunctioning; relay for up or down function malfunctioning (occasional)
3. Foot actuator assembly malfunctioning (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

One or more functions cannot be initiated from console caution

Some functions may be initiated from console but at least one may not; all functions can be initiated from hand control

Ranked causes

1. Program panel switch membrane is malfunctioning (common)
2. Program panel interface board is malfunctioning (common)
3. Wire connections loose (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

One or more functions cannot be initiated from hand control caution

Some functions may be initiated from hand control but at least one may not; all functions can be initiated from console

Ranked causes

1. Hand control panel switch membrane is malfunctioning (common)
2. Hand control board is malfunctioning (common)
3. Hand control coil cord has bad connection or break (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table up or down function does not work asymmetrically

One of table up/down functions operates properly but the other does not; all other functions work

Ranked causes

1. Wire connections loose to base actuator (common)
2. Interface board malfunctioning; relay for up or down function malfunctioning (occasional)
3. Base actuator assembly malfunctioning (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Tilt up or down function does not work asymmetrically

One of tilt up/down functions operates properly but the other does not; all other functions work

Ranked causes

1. Wire connections loose to tilt actuator assembly (common)
2. Interface board malfunctioning; relay for up or down function malfunctioning (occasional)
3. Tilt actuator assembly malfunctioning (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Base actuator continues running after table lowered all the way

After base actuator has lowered table top all the way down, the base actuator continues to run

Ranked causes

1. Base down limit switch out of adjustment (common)
2. Base down limit switch malfunctioning; stuck closed (occasional)

First check

Check adjustment of base down limit switch

Test point: Base down limit switch position
Expected: Properly adjusted to stop motor at bottom

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

One or more functions cannot be initiated from foot control caution

Some functions may be initiated from foot control but at least one may not; all functions can be initiated from hand control and console

Ranked causes

1. Foot switch for non-operable function is malfunctioning (common)
2. Wire connections loose (occasional)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Function drifts by itself

Base, tilt, back, or foot function drifts by itself; function operates properly otherwise

Ranked causes

1. Motor actuator brake malfunctioning (occasional)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Headrest drifts downward while supporting patient head patient safety

Headrest drifts downward while supporting patient head

Ranked causes

1. Headrest out of adjustment (common)

First check

Check adjustment of headrest

Test point: Headrest mechanism
Expected: Properly adjusted to prevent drift

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Headrest locking handles pop out of locked position

Ranked causes

1. Headrest handles handle stops need adjusted (common)

First check

Check adjustment of headrest handles handle stops

Test point: Headrest handles handle stops
Expected: Stops positioned to keep handles locked

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Stirrups do not lock into one of three positions properly patient safety

Stirrups are malfunctioning; do not lock into one of the three positions properly

Ranked causes

1. Stirrup index pin damaged or needs replacement (common)

First check

Check for damaged parts on stirrup assembly

Test point: Stirrup index pin and associated components
Expected: No visible damage; pin intact and functioning

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table does not operate from hand control only caution

Some hand control or console button is pressed but nothing happens; all functions work from foot control

Ranked causes

1. PC logic board is malfunctioning (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Table up does not work but table down does

TABLE UP function does not operate; TABLE DOWN function operates normally

Ranked causes

1. Gas spring weak (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Whirling or squeaking noise from actuator assembly

Whirling or squeaking noise is heard when an actuator assembly is being run

Ranked causes

1. Foreign matter on ball screw threads and/or lack of lubricant (common)

First check

Check for foreign matter and lubricant on ball screw threads

Test point: Ball screw threads on actuator
Expected: Clean and well lubricated

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Community

0 fixes logged by technicians through their AI, with outcomes, for this model.

ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.