Solar100 Malaysia Solar Troubleshooting Guide

What Happens If a Solar Panel Fails?

Updated: July 2026

If one solar panel fails, the effect on the overall system depends on the fault type, electrical design, inverter arrangement and whether the system uses conventional strings, power optimisers or microinverters. A damaged panel may produce less electricity, stop producing, reduce the output of a connected string or trigger an inverter warning. It does not always cause the entire solar system to stop.

Quick Answer One failed panel does not necessarily shut down the whole system. In a traditional string system, a serious fault or disconnection may affect the output of the connected string. In systems with panel-level power electronics, the effect may be more isolated to the affected panel or device. Check the monitoring platform for repeated underperformance, offline modules or fault codes, record the condition and contact the installer for safe testing. Do not touch damaged glass, exposed cables or connectors.

✓ SEDA-Related Standards Review

✓ SSM Registration Information Review

✓ Policy & Application Process Review

✓ After-Sales Support Assessment

✓ Consultation & Quotation Comparison

What Happens When One Solar Panel Fails?

The result can range from a small reduction in generation to the shutdown of an affected string. The exact effect depends on whether the problem is limited to the panel cells, frame, junction box, bypass diode, connector, cable or panel-level electronic equipment.

Reduced Panel Output

The panel may continue generating electricity but at a lower level due to cell damage, contamination, shading or internal electrical issues.

Panel Stops Producing

A serious internal fault, disconnected cable, failed junction box or failed panel-level device may cause the panel to stop contributing.

String Output Is Affected

In a conventional string arrangement, one fault may reduce or interrupt the performance of the connected string.

Inverter Warning Appears

The inverter may record low voltage, insulation problems, ground faults, arc-related warnings, string imbalance or communication loss.

System Continues Operating

Other strings or panel-level devices may continue producing even if one panel or one section is affected.

Safety Shutdown May Occur

Certain electrical faults may cause the inverter, protective device or service provider to isolate part or all of the system.

Possible Event	Likely System Effect	Recommended Response
Minor Cell Degradation	Gradual reduction in panel output.	Monitor the trend and arrange testing if the gap grows.
Bypass Diode Operation	Part of the panel may be bypassed, reducing output.	Investigate repeated or persistent underperformance.
Disconnected Connector	The panel or string may stop contributing.	Arrange professional inspection and reconnection.
Cracked Glass	Output may continue, but moisture and safety risks may increase.	Keep away and request prompt assessment.
Insulation Fault	The inverter may shut down or report a ground-related fault.	Do not restart repeatedly; contact technical support.
Failed Microinverter or Optimiser	One module or panel-level channel may go offline.	Use panel-level monitoring to identify the affected device.

A Failed Panel Does Not Always Mean Total System Failure: Many systems can continue operating at reduced capacity while the affected panel, string or panel-level device is inspected.

How Does Solar System Design Affect a Panel Failure?

Different inverter and wiring arrangements respond differently when one panel underperforms or becomes disconnected.

System Design	Possible Effect of One Panel Fault	Monitoring Visibility
Traditional String Inverter	A fault may reduce the affected string’s output or cause the string to stop contributing, depending on the fault.	Monitoring may show only inverter-level or string-level data.
String Inverter with Multiple MPPTs	The affected input may underperform while other inverter inputs continue operating.	Some platforms show separate input or MPPT information.
Power Optimiser System	The effect may be more isolated, but the optimiser, wiring or panel may still require diagnosis.	Panel-level or optimiser-level monitoring may be available.
Microinverter System	Other modules may continue producing while one panel or microinverter channel is offline.	Panel-level monitoring is often available, subject to platform setup.
Battery-Coupled or Hybrid System	Reduced solar input may affect battery charging, but battery and grid operation may continue according to the system design.	Monitoring may show solar, battery, load and grid flow separately.

String-Level Effect Series-connected panels share a current path, so one serious fault may affect the connected string.

Panel-Level Isolation Microinverters or optimisers may allow other panels to continue operating more independently.

Monitoring Detail Panel-level monitoring can make it easier to identify one underperforming module.

Design Limitation Monitoring detail alone does not confirm whether the fault is in the panel, connector, cable or panel-level electronics.

Panel-Level Monitoring Helps Locate a Problem but Does Not Replace Testing: A low-output module may be caused by dirt, shade, a connector, a damaged cable, a failed optimiser or the panel itself.

What Are the Common Types of Solar Panel Failure?

Cracked Glass

Impact, severe handling, falling debris or structural stress may crack the front glass.

Cell Cracks

Internal cell cracks may reduce output and may not always be visible from ground level.

Junction Box Failure

Heat, moisture, loose connections or component failure may affect the panel junction box.

Bypass Diode Failure

A failed or active bypass diode may reduce the amount of the panel that contributes to generation.

Connector or Cable Fault

Loose, incompatible, damaged or poorly terminated connectors can interrupt current or create heat.

Moisture Entry

Water entering damaged seals, cables or junction boxes may create insulation and corrosion problems.

Delamination or Discolouration

Material separation, bubbles or visible discolouration may indicate ageing or manufacturing-related concerns.

Hotspot Development

Localised heat may result from shading, cell damage, contamination or electrical resistance.

Broken or cracked front glass
Damaged backsheet
Loose frame
Frame corrosion
Cell cracking
Delamination
Discolouration
Hotspots
Failed bypass diode
Junction-box damage
Connector overheating
Cable insulation damage
Water entry
Ground or insulation fault
Animal damage
Debris impact
Excessive local shading
Panel-level electronic failure

Visible Damage Should Not Be Ignored Even If the Panel Still Produces: Cracked glass, damaged cables or burnt connectors may create moisture, electrical or safety concerns beyond the immediate generation loss.

What Are the Signs That a Solar Panel May Have Failed?

One panel shows unusually low output
One optimiser or microinverter is offline
One string produces less than similar strings
Daily generation drops without clear weather change
The same fault code repeatedly appears
An insulation fault is reported
A ground fault is reported
Visible glass is cracked
A panel appears burnt or discoloured
A connector or cable looks damaged
One section remains shaded without an external cause
Thermal imaging identifies a hotspot
Voltage or current readings are abnormal
The inverter repeatedly restarts
A panel stops reporting data
Output remains low after cleaning
Water is visible near electrical components
A burning smell is detected
Arcing or sparking is visible
A breaker or protective device repeatedly trips

Observed Sign	Possible Cause	Next Step
One Module Is Offline	Panel, optimiser, microinverter or communication issue	Check platform status and request panel-level diagnosis.
One String Is Underperforming	Panel fault, shading, connector, cable or design difference	Compare similar strings and arrange electrical testing.
Visible Crack	Impact, handling stress or structural damage	Keep away and arrange prompt inspection.
Hotspot Reported	Cell damage, resistance, shading or contamination	Request technical evaluation before continued operation.
Repeated Insulation Fault	Moisture, damaged cable, connector or panel insulation issue	Do not repeatedly reset the system; contact the provider.
Sudden System-Wide Reduction	Inverter, grid, multiple-string or monitoring issue	Confirm whether the problem is larger than one panel.

Low Output Alone Does Not Confirm Panel Failure: Dirt, bird droppings, new shade, cloudy weather, inverter limits, communication loss and grid events can produce similar symptoms.

How Is a Failed Solar Panel Diagnosed?

Diagnosis should identify whether the problem is the panel itself or another part of the circuit. A proper assessment may combine monitoring data, visual inspection and electrical testing.

Review Monitoring Data

Compare inverter inputs, strings, modules, fault codes and historical generation where available.

Check External Conditions

Confirm whether dirt, shading, leaves, bird droppings or recent weather can explain the reduction.

Perform Safe Visual Inspection

Inspect glass, frames, junction boxes, visible cables, connectors and mounting from a safe position.

Test the Electrical Circuit

Qualified personnel may check voltage, current, insulation, continuity and string behaviour as appropriate.

Use Additional Diagnostic Tools

Thermal imaging, curve tracing or other testing may be used where included and appropriate.

Confirm the Failed Component

The provider determines whether the issue involves the panel, connector, cable, optimiser, microinverter or another component.

A technical assessment may review:

Panel-level monitoring data
String-current comparison
String-voltage comparison
Inverter input readings
Fault-code history
Insulation-resistance results
Continuity results
Connector condition
Cable condition
Junction-box condition
Bypass-diode behaviour
Thermal-image findings
Visible cell or glass damage
Shading and soiling
Roof and mounting condition
Recent weather or impact events
Panel serial number
Manufacturer test requirements

A Module Showing Low Output Is Not Automatically Defective: The cause should be confirmed before a warranty claim or replacement is recommended.

What Should a Homeowner Do Immediately After Suspecting Panel Failure?

Keep Away from Visible Damage

Do not touch broken glass, exposed conductors, wet electrical equipment or burnt components.

Record the Evidence

Save screenshots, photographs, fault codes, dates and system status from a safe location.

Check the Handover Instructions

Review the approved customer shutdown procedure and emergency contact details supplied by the installer.

Contact the Service Provider

Explain whether there is physical damage, a monitoring alert, generation loss, water entry or unusual heat.

Keep children away from damaged equipment
Keep pets away from exposed cables
Do not climb onto the roof
Do not disconnect rooftop connectors
Do not remove a damaged panel
Do not cover a damaged panel with loose material
Do not repeatedly reset the inverter
Do not open the inverter or junction box
Do not hose damaged equipment
Do not touch wet electrical enclosures
Follow only approved shutdown instructions
Contact emergency services if fire or smoke appears

Solar DC Wiring May Remain Energised During Daylight: Turning off the inverter may not remove voltage from the rooftop panel wiring. Inspection and disconnection should be handled by appropriately qualified or competent personnel.

Can a Failed Solar Panel Be Repaired, or Must It Be Replaced?

The appropriate solution depends on the failed component. Some faults may involve connectors, cables or panel-level electronics rather than the panel itself. Physical damage to the panel laminate, cells, glass or junction box may lead to replacement rather than field repair.

Issue	Possible Action	Important Consideration
Loose or Damaged Connector	Replace or reterminate using an approved compatible method.	The connector and cable should be checked for heat damage.
Damaged DC Cable	Replace the affected cable section or circuit as appropriate.	Route, insulation and protection should be reviewed.
Failed Optimiser or Microinverter	Replace the failed panel-level electronic device.	Compatibility, commissioning and monitoring setup must be checked.
Cracked Panel Glass	Panel replacement may be recommended.	Moisture entry and electrical safety should be assessed promptly.
Internal Cell or Laminate Failure	Panel replacement may be required.	Warranty evidence and diagnostic results may be needed.
Bypass Diode or Junction-Box Issue	Follow manufacturer-approved repair or replacement procedure.	Unauthorised field repair may affect warranty or safety.

Replacement planning may need to consider:

Original panel model
Original panel power rating
Panel dimensions
Electrical voltage characteristics
Electrical current characteristics
Connector compatibility
String design
Inverter input limits
Mounting-clamp zones
Frame thickness
Roof access
Replacement-panel availability
Manufacturer approval
Warranty requirements
Monitoring reconfiguration
Testing and recommissioning
Labelling updates
Disposal or recycling arrangements

The Highest-Wattage Replacement Panel Is Not Automatically Suitable: Electrical characteristics, physical dimensions, string compatibility, inverter limits and mounting requirements must be considered.

How Does a Solar Panel Warranty Claim Usually Work?

Warranty procedures vary by manufacturer, distributor, installer and contract. A claim may require proof of purchase, panel serial numbers, photographs, monitoring records and technical test results.

Report the Problem

Notify the installer or agreed service contact and provide the system address, fault details and photographs.

Confirm the Component

Testing determines whether the problem involves the panel or another system component.

Prepare Claim Evidence

Serial numbers, invoices, commissioning records, photographs and technical reports may be collected.

Submit the Claim

The installer, distributor, manufacturer or customer submits the claim according to the applicable process.

Receive the Decision

The claim may be approved, rejected or returned for additional information.

Arrange Replacement and Testing

If approved, labour, transport, access, replacement and recommissioning arrangements should be confirmed.

Warranty Item	Possible Coverage	Possible Exclusion or Separate Cost
Product Warranty	Manufacturing defect or covered material failure.	Labour, access and transport may not always be included.
Performance Warranty	Specified long-term output condition, subject to terms and testing.	Normal site variation or unverified monitoring data may not qualify.
Workmanship Warranty	Covered installation-related defects under the installer’s terms.	Manufacturer panel defects may follow a separate process.
Insurance Claim	Storm, impact or other insured event, subject to the policy.	Excess, exclusions and documentation may apply.
Maintenance Contract	Diagnosis, inspection or replacement coordination where included.	Parts and emergency visits may be excluded.

Useful warranty records include:

Purchase invoice
Installation contract
Panel datasheet
Panel serial numbers
Inverter serial number
Commissioning report
System layout
String design
Monitoring screenshots
Fault-code history
Maintenance records
Cleaning records
Photographs of damage
Technical test report
Installer correspondence
Manufacturer correspondence
Warranty terms
Insurance information

A Replacement Panel May Be Covered While Labour Is Not: Confirm separately who pays for testing, roof access, transport, removal, installation, monitoring setup and recommissioning.

How Can Homeowners Reduce the Risk of Solar Panel Failure?

Choose suitable certified equipment
Use a properly designed system
Use compatible connectors
Protect cables from sharp edges
Support cables correctly
Prevent loose rooftop wiring
Maintain proper panel clamping
Avoid walking on panels
Keep roof drainage clear
Control nearby vegetation
Review bird and animal activity
Inspect after severe weather
Monitor generation regularly
Respond to repeated faults promptly
Follow manufacturer maintenance guidance
Keep warranty records
Use trained maintenance personnel
Coordinate roof work with the solar provider
Avoid unapproved electrical modifications
Maintain a documented service history

Correct Installation

Appropriate mounting, cable management, connectors and commissioning reduce avoidable installation-related faults.

Regular Monitoring

Early detection of one underperforming panel or string may reduce the time a fault remains unresolved.

Safe Maintenance

Avoiding panel walking, harsh cleaning and unapproved repair helps reduce physical damage.

Recordkeeping

Serial numbers, reports and monitoring records can support diagnosis and warranty claims.

Not Every Panel Failure Can Be Prevented: Manufacturing defects, severe weather, impact and long-term material ageing may still occur even when a system is properly maintained.

What Panel-Failure Questions Should You Ask Before Signing?

What happens if one solar panel stops producing?
Will the rest of the system continue operating?
Does the system provide panel-level monitoring?
Can the monitoring platform identify one failed panel?
Will I receive access to panel-level data?
Who diagnoses suspected panel failure?
Is fault diagnosis included during the warranty period?
What testing is used to confirm a panel defect?
Who submits the manufacturer warranty claim?
What documents are needed for a claim?
Are panel serial numbers recorded during installation?
Does the warranty include replacement labour?
Does the warranty include roof access?
Does the warranty include transport?
Does the warranty include recommissioning?
What happens if the original panel model is unavailable?
How will a compatible replacement be selected?
Will replacement affect the string design?
Will monitoring need to be reconfigured?
Will a technical report be provided?
How quickly will a failed panel be assessed?
Is emergency support available for electrical damage?
Who is responsible for water or roof damage?
What happens if the installer stops operating?
Can another authorised contractor process the claim?
Which failure types are excluded?
Does impact damage require an insurance claim?
How should a damaged panel be isolated safely?
Who disposes of the failed panel?
Will the replacement panel have a new warranty?

What Is Solar100’s Role in Solar Panel Failure Comparison?

Solar100

Supports solar-provider discovery
Helps customers organise initial project information
Supports initial quotation comparison
Helps identify differences in warranty and service scope
Does not diagnose failed solar panels
Does not approve warranty claims or guarantee replacement

Selected Provider and Equipment Manufacturer

Inspect and test the affected circuit
Confirm whether the panel or another component failed
Prepare or support warranty documentation
Recommend compatible repair or replacement
Complete testing and recommissioning
Remain responsible for the agreed technical and warranty scope

Frequently Asked Questions

What happens if one solar panel fails?

The system may continue operating at reduced output. The effect depends on the fault type and whether the system uses string wiring, microinverters or power optimisers.

Will one failed solar panel stop the whole system?

Not always. One failed panel may affect only one module, one panel-level device, one string or one inverter input. Other sections may continue generating.

How do I know whether a solar panel has failed?

Warning signs include one module showing low output, a string underperforming, repeated fault codes, cracked glass, damaged cables or abnormal electrical test results.

Can a failed solar panel still produce electricity?

Yes. Some damaged panels continue producing at a reduced level, which is why visible damage should still be inspected.

Can a failed solar panel be repaired?

Some related faults, such as damaged connectors or panel-level electronics, may be repairable or replaceable. Internal panel damage may require full panel replacement.

Can I replace one panel with a different model?

A different model may be possible only after checking electrical characteristics, physical dimensions, string compatibility, inverter limits and mounting requirements.

Is a failed solar panel covered by warranty?

It depends on the cause, warranty terms, evidence and diagnostic results. Impact, unauthorised work or excluded site conditions may not be covered.

Does panel warranty include replacement labour?

Not necessarily. Product replacement, labour, transport, roof access and recommissioning may have separate coverage.

Should I switch off the solar system if a panel is damaged?

Follow only the approved shutdown procedure provided by the installer. Solar DC wiring may remain energised during daylight even after the inverter is switched off.

Does Solar100 diagnose or replace failed solar panels?

No. Solar100 supports provider discovery and quotation comparison. Diagnosis, testing, warranty claims, repairs and replacement remain the responsibility of the selected provider and relevant manufacturer.

The information on this page is provided for general educational and comparison purposes. The effect of a failed solar panel, diagnosis method, shutdown requirement, repairability, replacement compatibility, warranty coverage, labour responsibility and service response depend on the specific panel, inverter, electrical design, mounting system, fault type, manufacturer instructions, monitoring platform, system condition, site safety and contractual terms. Homeowners should not touch damaged panels, exposed cables, connectors, junction boxes or wet electrical equipment. Electrical inspection, testing, isolation, disconnection, repair, replacement and recommissioning should be performed by appropriately qualified, registered or competent personnel where required. Solar100 is a provider-discovery and quotation-comparison platform. It is not an installer, maintenance contractor, electrical contractor, engineer, competent person, testing laboratory, equipment manufacturer, distributor, warranty administrator, insurer or approving authority and does not guarantee fault diagnosis, warranty approval, replacement availability, service response, system output, savings, roof condition or equipment service life.

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