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Case Studies

Automotive Parts Manufacturer - Trumpf / Haas Laser Etching Part Numbers

Injection moulding machine

A major automotive parts manufacturer had a production line stopped because the Trumpf / Haas laser that etched the hybrid electronic modules for the antilock braking system controls they produce was down. Two maintenance shifts had been working furiously in the clean room to get the line back up and running, and when they reached a stopping point, receiving CAN bus communication errors, AFI Systems were called in to assist at 7:30pm on a Sunday evening.

First, we requested that they email or text close-up pictures of the suspect circuit board. Then, from the pictures and the description of the failure, parts were identified and pulled from inventory at our facility before making the service call. The circuit board was checked for problems on-site using a V-I curve tracer, an IC tester and universal programmer, but no physical problems were found, although it did contain several memory devices that could have become corrupted.

The board was then re-installed on the machine to begin troubleshooting the system, and it was eventually discovered that the laser's PSB100 power supply board had been failing intermittently, and had caused the memory devices on the CPU board to become corrupted. Another production line with a similar laser was taken down momentarily to copy the memory devices and reprogram the ones on the bad board.

The failing power supply had also caused problems with the laser's PC, one of three computers that perform different functions on the machine. After working 15 hours through the night without a break, the laser was finally brought back into operation late Monday morning, and production was resumed.

Plastic Injection Molding Machine

Injection moulding machine

A new customer had been trying to get a Mitsubishi 90MJII-5 injection molding machine back up and running after it had been down for several months. Initially, the old CRT monitor had failed, and the OEM wanted around $6000.00 for a replacement, which bearing in mind the age of the machine, was not worth spending. Another repair company had taken the monitor, determined that is was not repairable, and sent a technician to retrofit an LCD monitor in it's place. Unfortunately, not only were they unsuccessful in getting the LCD to work, they also damaged two other circuit boards in the machine along with the Hitachi CPU-03Ha PLC processor, and burned up some wiring on a good machine they had used to troubleshoot the bad one. They then bailed out and left the customer with a huge mess.

AFI had an engineer on site to investigate the problem, determine if it was feasible to get the machine back up and running, and come up with a plan of action. After checking the machine, it was found that some ICs had been damaged on the ALU board (p/n:36990-PR01B/95I062) where the video signal connects.

The ALU board was taken and repairs carried out. Since the original CRT monitor had been disposed of, we had to do extensive research to determine the video format, as the information was not available from the OEM and we did not even know the part number of the old CRT. Reverse engineering was carried out on the ALU board to determine the pinout of the video connector, and then the board was powered and an oscilloscope used to check the voltage level, polarity and frequency of the horizontal and vertical sync signals, and to look at the amplitude and format of the actual video information. Next, the search started for a video signal converter that could handle the unusual proprietary sync frequencies, so that a standard VGA monitor could be installed.

Finally a working converter was located, and the system set up on the bench to check the video output. When the new LCD monitor, video converter and repaired ALU board were installed on the machine, an error was received indicating that the machine initialization procedure needed to be carried out. It was then discovered that the keyboard was not responding, and the PLC would not go into run mode. The keyboard microprocessor board was taken for repair (OPE board p/n 3A133665X001A), and it was discovered that it also had several blown ICs and the EPROM had become corrupted.

Fortunately there was another machine with the same keyboard CPU, so another site visit was scheduled and our universal programmer was used to copy the contents of the good EPROM, burn a new device for the faulty board, and save a backup to out PC in the process. The PLC program was also backed up in this manner as it was stored permanently on EPROM in the ROM-16H module. A good PLC CPU was borrowed from a similar machine, the EPROM module swapped over, and finally we were able to run the initialization procedure and get the machine back into operation, saving it from the scrap yard and saving our customer the many thousands of dollars it would have cost to replace it.