The BOJ field diagnostics method
Build a repeatable sequence for troubleshooting PLC-related faults.
INDUSTRIAL DIAGNOSTICS · BOJ METHOD
Diagnose real Siemens S7-300/400 faults with method and evidence
Learn a practical sequence for interpreting symptoms, gathering evidence and narrowing down the probable cause across CPUs, PROFIBUS, modules and field signals. Course materials are currently available in Spanish.
Course language: Spanish · One-time payment · Permanent course access · 1 month of BOJ S7-PLC PRO · 1 device
A method built in industrial plants, not only in a classroom. Real work for:
- YPF
- Ledesma
- Generación Mediterránea
- TGN
- CALSA
- GETSA
What you will learn
CPU operating states and diagnostic LEDs
Use STEP 7 Classic, Diagnostic Buffer and HW Config Online with a clear purpose.
STEP 7 Classic and SIMATIC Manager workflow
Separate logic, network, module, wiring, power and process-related causes.
Diagnostic Buffer and online hardware diagnostics
Reduce unnecessary component changes and trial-and-error interventions.
PROFIBUS faults and distributed I/O
Build a repeatable sequence for troubleshooting PLC-related faults.
Digital and analog signal verification
Use STEP 7 Classic, Diagnostic Buffer and HW Config Online with a clear purpose.
Intermittent faults and misleading symptoms
Separate logic, network, module, wiring, power and process-related causes.
Applied cases and intervention criteria
Reduce unnecessary component changes and trial-and-error interventions.
What is included
Applied training plus a professional tool for clearer Siemens S7-300/400 diagnostics.
Applied S7-300/400 course
Preview the first 8 pages of the manual
Permanent access to the S7-300/400 industrial diagnostics course
Professional technical manual with a field-oriented method
One month of BOJ S7-PLC PRO for one device
Applied cases involving CPU states, SF/BF, PROFIBUS, modules and signals
Built on more than 15 years of industrial automation, maintenance and diagnostics experience.
PRO APP — 1 month of BOJ S7-PLC PRO
Explore real views of the app
Screen 1 of 8
Set up the CPU and LEDsSelect the model and record the status observed on the PLC front panel.
Your diagnostic copilot at the control panel: it organizes symptoms, LEDs, hypotheses and checks step by step.
1 month1 device
With the PRO App you can:
- Diagnose by symptoms, LEDs, network, modules and signals
- Review prioritized technical hypotheses
- Follow step-by-step checks
- Use it offline for up to 2 days
- Access it from a browser or install it as an app
Connect to the PLC with confidence and diagnose with professional judgment.
Course program
The syllabus follows the real logic of an industrial diagnosis.
- 01The BOJ field diagnostics method
- 02CPU operating states and diagnostic LEDs
- 03STEP 7 Classic and SIMATIC Manager workflow
- 04Diagnostic Buffer and online hardware diagnostics
- 05PROFIBUS faults and distributed I/O
- 06Digital and analog signal verification
- 07Intermittent faults and misleading symptoms
- 08Applied cases and intervention criteria
Who it is for
For people who solve real faults under production pressure, with limited time and incomplete symptoms.
Industrial maintenance technicians
Electrical and instrumentation professionals
Automation specialists and PLC programmers
Engineers working with Siemens S7-300/400 systems
Industrial electricians
Technical training centers
It does not replace field experience: it organizes and reinforces it.
Your instructor
Walter Adrián Boj
Walter Adrián Boj is an industrial automation and Siemens PLC diagnostics specialist with more than 15 years of plant experience in maintenance, programming, industrial networks, migrations and real S7-300/400 faults.
View professional profileAccess the course + BOJ S7-PLC PRO
A technical offer for organizing the diagnosis before intervening.
A stopped machine can cost more than this training. The objective is to investigate before changing hardware, restarting equipment or intervening without evidence.
One-time payment · Permanent course access
COURSE + PRO APP
S7-300/400 Diagnostics Course + PRO APP
Includes 1 month of BOJ S7-PLC PROOne-time payment65 USD
Permanent course access + PRO tool for 1 month.
What is included
Everything you receive
Applied S7-300/400 course
- Permanent access to the S7-300/400 industrial diagnostics course
- Professional technical manual with a field-oriented method
- One month of BOJ S7-PLC PRO for one device
- Applied cases involving CPU states, SF/BF, PROFIBUS, modules and signals
PRO App included
- Diagnose by symptoms, LEDs, network, modules and signals
- Review prioritized technical hypotheses
- Follow step-by-step checks
Course language: Spanish · One-time payment · Permanent course access · 1 month of BOJ S7-PLC PRO · 1 device
Will you use the app regularly or with a team? View PRO plans.
Digital access. Always verify conclusions in the field before intervening.
The BOJ Method
From the symptom to a probable cause, with evidence instead of trial and error.
A repeatable sequence created from real plant work for situations where the machine is stopped and time is limited.
Observe
Record symptoms, LEDs and operating conditions.
Organize
Separate CPU, network, module, signal and process evidence.
Prioritize
Build a defensible technical hypothesis.
Verify
Check the evidence before intervening.
What problem it solves
This is not a generic programming course. It is designed for real plant diagnostics.
Develop a clearer technical response when production pressure is high.
Build a repeatable sequence for troubleshooting PLC-related faults.
Develop a clearer technical response when production pressure is high.
Use STEP 7 Classic, Diagnostic Buffer and HW Config Online with a clear purpose.
Develop a clearer technical response when production pressure is high.
Separate logic, network, module, wiring, power and process-related causes.
Develop a clearer technical response when production pressure is high.
Reduce unnecessary component changes and trial-and-error interventions.
Develop a clearer technical response when production pressure is high.
Permanent access to the S7-300/400 industrial diagnostics course
Built on more than 15 years of industrial automation, maintenance and diagnostics experience.
Professional technical manual with a field-oriented method
Built on more than 15 years of industrial automation, maintenance and diagnostics experience.
Mistakes this course helps prevent
A structured diagnosis avoids costly decisions.
Losing time through trial and error
Changing modules without a clear hypothesis
Misreading LEDs and CPU states
Missing PROFIBUS network faults
Failing to record symptoms and evidence
Making the problem worse through an unplanned intervention
What technicians say
Real experience in the field.
Antes me costaba ordenar el diagnóstico cuando una CPU quedaba en STOP o aparecía BF. Con el curso entendí cómo analizar la falla por etapas y la app me sirve como guía rápida en planta. Hoy tengo más seguridad para intervenir sin empezar cambiando componentes al azar.Original testimonial in Spanish
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Frequently asked questions
Before purchasing the course
Is the course delivered online?
Yes. It provides permanent online access to the course material after purchase confirmation.
Which Siemens systems does it cover?
The main focus is Siemens S7-300/400 with STEP 7 Classic, including CPU states, hardware, PROFIBUS, modules and field signals.
How long is the refund period?
The purchase is processed by Hotmart and includes a 7-day refund guarantee under Hotmart's applicable process and conditions.
Is it suitable for beginners?
It is designed for people with a basic electrical, maintenance or automation background who want a structured diagnostic method.
What is included with the PRO App?
The offer includes one month of BOJ S7-PLC PRO for one device, with no automatic renewal.
If you work with Siemens S7-300/400 PLCs and need clearer diagnostic judgment, this course gives you a method, structure and technical support for better interventions.
Course language: Spanish · One-time payment · Permanent course access · 1 month of BOJ S7-PLC PRO · 1 device
Buy course + PRO App — 65 USD
Digital access · Course + PRO App