CASE STUDY: Using Freeze Spray to Bring a $10M System Back to Life
CASE STUDY: Using Freeze Spray to Bring a $10M System Back to Life
Electronic component failures are inevitable — aging, connection failures, overcurrent, over-temperature, and overvoltage all cause components to fail, often without visible warning. When a $10M industrial SCADA system (“Raising Machine”) from a textile facility arrived at the repair bench with a blank screen and a persistent temperature alarm preventing boot, the diagnostic challenge was locating the fault in a complex SMD-populated CPU board without testing every component individually. Chemtronics Freeze Spray provided the solution: by applying freeze spray to the suspected CPU area, the frost pattern revealed where heat was concentrated — identifying two shorted 1K resistors that were triggering the temperature alarm. Total repair time: under 30 minutes. System restored to full operation.
7-Step Freeze Spray Fault Isolation Process
| Step | Action | Test Case Result |
|---|---|---|
| 1. Identify symptoms | Document all fault indicators: no boot, intermittent operation, visible damage, no power, excessive heat, unusual noise or smell, display or LED failures | Red LED temperature alarm constantly on; system would not boot. Manual indicated alarm could originate from CPU, I/O card, or display (RS485). Display not attached; I/O card clear — CPU suspected. |
| 2. Check for visual damage | Inspect for burned components, charred areas, cracked PCB, missing or bent components, corrosion, moisture damage, melted components | No visual signs of damage to any wire, connection, or component. No burning or melting. Proceeded to next step. |
| 3. Apply freeze spray | Power off circuit. Identify suspected area. Hold can 4–6 inches away; spray 3–5 seconds. Observe frost pattern and circuit behavior. Repeat on other areas if needed. | Freeze spray applied to CPU area. Frost formed across the board. System powered on with frost applied — temperature alarm cleared temporarily, confirming thermal fault in the frosted area. |
| 4. Isolate the fault | Power on circuit and observe where frost melts first — the area of highest heat generation. Mark the area. Power off and isolate the specific component. | Ice melted first on the right side of the PCB. Area marked. Two 1K SMD resistors found to be short-circuiting, drawing excess current and generating the heat triggering the temperature alarm. |
| 5. Test components | Use multimeter or SMD tester to measure resistance, voltage, and continuity on isolated components. Compare to datasheet specifications. | Both 1K resistors confirmed shorted via multimeter. Resistance measured near zero — confirmed short circuit. |
| 6. Replace or repair | Source exact replacement components. De-solder damaged components carefully. Install and solder replacements. Inspect for bridges or alignment issues. | Both shorted 1K resistors replaced using hot air gun and flux. Board inspected for solder bridges. |
| 7. Reassemble and document | Reassemble device. Test fully. Document repair process, parts used, and test results for future reference. | System rebooted with no temperature alarm. Fully cleaned, reassembled, and tested with LCD display. Operated correctly through 30-minute test with no alarms. |
Frequently Asked Questions
How does freeze spray identify a faulty component?
Freeze spray works by rapidly cooling a localized area of the PCB to below 0°C. When the board is powered on with frost applied, two things can happen: intermittent faults caused by thermal expansion (components that fail when hot) may temporarily clear when cooled, confirming a thermal-dependent fault; and when power is applied, the area of highest heat generation — the faulty component drawing excess current — melts the frost first, visually pinpointing the fault location. This makes freeze spray particularly effective for diagnosing temperature-related faults and short circuits in complex SMD boards where individual component testing would be impractical.
Is it safe to apply freeze spray to a powered circuit board?
For the fault isolation technique described in this case study (observing where frost melts first), the board must be powered on after the freeze spray is applied — not while spraying. Always power off and unplug before applying freeze spray, then power on to observe the frost melt pattern. Never spray freeze spray onto a live board. Also ensure the area is well-ventilated, avoid contact with skin and eyes, and do not spray near open flames. Use freeze spray rated for electronics — Chemtronics Freeze Spray is formulated specifically for electronic diagnostic use.
What types of faults can freeze spray diagnose?
Freeze spray is most effective for: thermal-dependent intermittent faults (components that fail when hot and recover when cold), short circuits generating localized heat (as in this case study), cold solder joints that change resistance with temperature, and components with temperature-dependent failure modes (capacitors, resistors, semiconductors). It is less useful for faults that are not temperature-dependent, such as open traces, connector failures, or firmware issues. Use freeze spray as part of a systematic diagnostic process — after visual inspection and symptom documentation — not as a first-step shotgun approach.
What tools are needed for a freeze spray fault isolation repair?
For the complete repair process: freeze spray, a protected power supply, multimeter or SMD tester, hot air gun (for SMD desoldering and rework), flux, precision tweezers, and a multi-bit screwdriver set for system disassembly. Replacement components must be exact matches in type and specification — verify against the component datasheet before ordering. Document all parts replaced and test results for future troubleshooting reference.
Shop Chemtronics Freeze Spray & Electronics Cleaners at MTE Solutions →
Content developed in partnership with Chemtronics.
