PCB troubleshooting application notes

Polar Application Note library

The Polar Application Note library includes a comprehensive resource of information on PCB fault finding. Use the search engine above to locate your subject of interest.


Probe force analysis of GRS500

This application note contains the results of an investigation into the force applied by the test probe on a Polar GRS500 Graphical Repair System. 


Using the External Instruments function on the GRS500

This note describes how the GRS500 External Instrument function allows the GRS500 user to link the GRS500 to external test/measurement equipment.


Which CAD files can I import and use in the GRS500?

The GRS500 cad input processors import and read a comprehensive range of CAD formats to automatically generate test programs and graphical repair information.  This note lists the ASCII output files you need to generate from CAD or CAM systems in order to prepare your GRS500 test program. 

This document is also applicable for GRS CADView graphical cad viewer repair test software.


Signature differences — device vendor differences, or a genuine fault?

This note discusses using Nodal Impedance techniques to locate faults on a net. Some net faults can prove difficult to detect using conventional methods; by using net impedance analysis many hard to find faults can be located using logical techniques.


GRS500 PCB repair test system software - introducing the main toolbar icons

This application note supplements the GRS500 operator manual with an "at a glance" guide to the function of the primary toolbar items.


GRS500 PCB repair test system - test list functions

This application note supplements the GRS500 operator manual with a description of test list operations on the GRS500.


Toneohms find ground plane shorts

This presentation describes how Polar's Toneohm 950's vector plane stimulus (VPS) helps find ground plane shorts. (PowerPoint presentation 1Mb)


How Toneohms and repair software can find ground plane shorts  

PCB test – power to ground shorts: how the Toneohm 950 helps you find them,
and, how FTCam Pro can give you further help with plane short location on complex boards


Introductory tutorial for FTCam Pro

AP137_800_600   Low resolution slide show: 
AP137_1024_768 Hi resolution slide show:    
AP137.ppt (right click and choose Save Target as)

Powerpoint presentation for you to freely distribute for training purposes within your company


Interpreting troubleshooting system results

Testing and fault finding PCBs requires detective work and skill, Nodal Impedance or nodal impedance faultfinding can give you clues to point you in the direction of the fault.


Fault finding conformal coated boards

When you are faced with faultfinding a conformally coated PCB it is essential that the coating is carefully cleaned from the PCB prior to attempting to diagnose the fault. This note proposes a professional alternative to cleaning with commercial solvents..


Accurate programming of FT100s

For fine pitch PCBs where you have no access to CAD data this note discusses the important steps to take to ensure accurate and repeatable test programming.


Graphical PCB repair and programming FTCam Pro 

Polar FTCam Pro speeds program generation on FT100s flying probe faultfinding systems and PCB fault locators; Polar's FTCam Pro allows program generation from most popular CAD systems. This note will help if you need to faultfind PCBs that fail functional test.


Using the PFL/FT100 Board Layout View

This note describes how to simplify fault finding by using a scanned picture of your PCB for guided fault finding.


How to approach fault finding

Locating faults on PCBs requires some practice to become successful. Polar Fault Locators allow you to take an alternative approach to the 'scope and DMM techniques you may be used to. This note describes how to approach fault finding using a Polar Fault Locator


In-Circuit Functional Test

Sophisticated software device simulation techniques in modern ICT Fault Locators now allow rapid and effective location of faulty digital ICs without removal from circuit. This note describes locating faulty digital ICs easily with In Circuit Functional Test


Introduction to Nodal Impedance troubleshooting

Using nodal impedance analysis you can troubleshoot those hard to locate PCB faults down to component level — without having detailed circuit knowledge, without applying power — and without documentation.


NDS Broadcast uses PFL780

NDS Broadcast is one of the world's leading manufacturers of turnkey digital video compression systems. The company uses a Polar PFL780 fault locator as an adjunct to its ATE, and now considers it an indispensable and very cost-effective production tool.


Advanced bus fault finding techniques

Locating obscure loading faults and shorts on microprocessor buses on multi-layer circuit boards can seem a daunting task. Combining a multi-range shorts locator such as the Polar Instruments TONEOHM 950 with a systematic approach to the fault can help locate the toughest short.


Bus fault finding techniques

When testing PCBs a signature shows up faulty on a bus line it can be difficult to decide which device is causing the problem. Moving the COM line to the faulty bus line can help isolate the device causing the problem. This note describes how to pin-point faulty devices on bus systems without removal from circuit.


Bus fault finding with pull up resistors

The bus lines on many high speed bus-based circuits are designed using transmission lines techniques and employ terminating resistors (often referred to as bus pull ups) for impedance matching. Using nodal impedance analysis you can quickly locate faults on address and data bus lines.


Use of guards to isolate bus-connected devices

In a bus system, the set of connecting lines connects all devices on the bus in parallel. This can make it difficult during pcb testing to pinpoint which chip is actually faulty. Application of high or low "guard" voltages can help isolate the device under test without removing it from the circuit..


Stability of Nodal impedance signatures

When using Nodal Impedance Analysis to test digital devices on a pcb you will sometimes encounter difficulty achieving stable signatures. Knowing how the Nodal Impedance Analysis fault locator tests devices can help you develop techniques to reduce spurious FAIL results for good devices.


Frequently asked questions on PCB faultfinding

PCB test and fault-finding has become increasingly complex with the increase in high density parts and the widespread use of multi-layer PCBs. This note contains some answers to questions most frequently asked of us.


Simplify fault finding by storing different vendor signatures

During PCB test and fault finding with the Polar PFL, variations in signatures due to different vendor input protection schemes can produce false FAIL comparison results in good devices. You can reduce spurious FAIL results by acquiring reference signatures for each of your device vendors.


Pin By Pin learning and testing

Using the Pin by Pin function of the PFL PCB fault locator can dramatically reduce the programming and testing time for special or inaccessible devices.

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