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ECG units

Schiller AT-1: troubleshooting and error codes

The ServiceForge knowledge base holds 8 documented symptoms for the Schiller AT-1, with 16 ranked causes, 5 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

Printer produces uneven output

Printout fading at top or bottom, uneven darkness across paper width

Ranked causes

  1. 1. Uneven spring pressure from printhead to roller (common)
  2. 2. Worn or misaligned roller (common)
  3. 3. Dirty printhead pixels (occasional)
  4. 4. Poor quality or aged paper (occasional)

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

Paper jams or does not stop at correct position

Paper handling malfunction during printing operation

Ranked causes

  1. 1. Dirty paper mark detector (common)
  2. 2. Poor quality paper installed (common)
  3. 3. Printer motor fault (occasional)

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

Printout too faint or too dark; general quality poor

Print darkness or contrast is incorrect or overall print quality is degraded

Ranked causes

  1. 1. Dirty printhead pixels (common)
  2. 2. Poor quality or aged paper (common)
  3. 3. Incorrect TPH temperature setting (occasional)

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

External printer no printout

External inkjet printer connected via USB or Centronics produces no output

Ranked causes

  1. 1. Both USB and Centronics interfaces simultaneously engaged (common)
  2. 2. No format selected in settings (occasional)

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

Calibration: Battery Charge Voltage high voltage

Battery charge voltage adjustment on control and power supply board MK 11-10 requires measurement and potentiometer VR4 adjustment to nominal 13.5 V with 5 mA maximum current.

Ranked causes

  1. 1. Battery charge voltage out of specification (unknown)
First check

Measure voltage across 2.7 kOhm 250 mW resistor simulating discharged battery

Test point
TP12 and TP13 battery connectors
Expected
13.5 V, nominal
Tools
Digital Multimeter

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

Calibration: ECG Amplifier Reference Voltage and PWM Ramp high voltage

Adjustment of +/- 2 V reference voltage rails and PWM ramp slope on ECG interface board MK 11-2 using potentiometers VR2 and VR3. Both must be adjusted simultaneously. Reference voltages are checked yearly.

Ranked causes

  1. 1. ECG amplifier reference voltage or PWM ramp out of specification (unknown)
First check

Measure voltage difference between +2V and -2V reference on pins 1 and 7 of operational amplifier U100

Test point
U100 pin 1 and pin 7
Expected
4000 mV +/- 2 mV, +/- 2 mV
Tools
Digital Multimeter

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

External printer poor quality printout

External inkjet printer output has quality issues or low contrast

Ranked causes

  1. 1. Improper grounding between printer and AT-1 smartprint (common)

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

Faulty pixel in printhead

Horizontal white line visible in printout indicating non-functional printhead pixel

Ranked causes

  1. 1. Printhead pixel defect (rare)

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.