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Output | Software Solutions | Proofing | Color, Screening and Calibration | Scanning | Digital Photography | Consumables | POS
The L-Box PM is a procedure that we have to perform on all the Lotem fiber head laser boxes. We have to perform it only once in the lifetime of the L-Box. The PM consists of replacing the electronic boards that are in contact with the laser diodes. We have to replace one motherboard and one or two daughterboard depending on the number of beams we have, 24 or 48. The new boards are protected against humidity.
We have to do it because we found that we have risks of condensation in the L-Box. The condensation causes corrosion of the connectors and as a result we risk having short circuits on the boards. Condensation happens when the dew point temperature is reached. The dew point temperature varies according to the atmospheric pressure and humidity and is lower or equal to the ambient temperature. Depending on the customer environment the temperature inside the L-Box is sometimes close or equal to the dew point temperature. In order to moved away from the dew point temperature we increased the temperature of the L-Box in the new software (version 3.6) from 21°c to 23°c (69.8°F to 73.4°F). Since we felt this is not enough we also decided to replace the boards inside the L-Box with new ones that are protected against humidity.
What are the risks not performing it?
Not performing the L-Box PM increases the risks of short circuits in the L-Box. As a result the L-Box will have to be replaced. In extremes cases we may have to replace the whole machine. It happened in Sweden a few months ago. The cost of repairing the machine on site was too high and we decided to replace it. What happened in Sweden is that a short circuit in the L-Box caused a voltage surge and high current flowing through the wires of the L-Box. The high current melted some cables and some plastic covers. Smoke came out of the machine but since it is fireproof nothing happened to the surroundings. The machine was not repairable on site and was replaced.
What is the urgency performing the L-Box PM?
Although we don't want to create panic in the field and a huge load over the service organization we still would like everyone to understand that it is important to perform the PM as soon as possible. We do fear that more L-Boxes will fail in the field. Since it depends on the environmental conditions of the machine it is difficult to pinpoint to a specific regions and concentrate on it thus we must work globally which makes the task more difficult hence our wish to work quickly.
On which Lotems do we have to do it?
The L-Box PM must be performed on all fiber head Lotems that have maintenance contract or are under warranty. That includes the Lotem 800, Lotem 400, Lotem XL and Lotem Flexo.
What about Time & Material customers?
Time & Material customers will receive the L-Box PM parts free of charge and will pay for the labor. We recommend pairing the L-Box PM with a regular PM in order to save cost both the customer and us. A letter explaining that was sent to the DU's with a recommendation to forward it to all T&M customers. We have to do that in order not to carry liability in case something goes wrong with the L-Box. We hope customers will understand we're trying to help them and we expect them to contact our service organization to schedule the PM.
Who is performing the L-Box PM?
Any trained Lotem engineer can perform the L-Box PM. No additional training is required. The PM comes with a very detailed procedure and a CD movie. It is a good idea to read the procedure and watch the movie before performing the PM.
How do I perform the L-Box PM?
Beyond the straightforward answer of "read the procedure and do it" I think it worth spending a little time thinking how to perform the PM. The reason is that your are going to take a working Lotem out of production for 3 to 5 hours and that's not something a customer likes. The PM involves disconnecting all the laser diodes and bits and pieces of the L-BOX. This is an open-heart surgery of the L-Box. You want to be prepared and you want your customer to be prepared. The first step is to schedule the PM so it is the most convenient time for the customer. Tell him it will take about 4 - 6 hours so you're not under pressure. Explain what you're going to do but don't go into the details. Tell him you're going to replace 2 or 3 boards in the L-Box because we want to prevent a problem. On site you have to work on the floor, which is painful over time. Take that into account and rest from time to time. Be organized and follow the procedure to the letter. Once the work is done make sure you didn't forget anything and test the machine before giving it back to the customer. If you feel you're in troubles notify your customer that it will take you longer and call for help. Don't wait for the last minute to give the bad news to your customer and don't fight with the machine, call for help.
When is the L-Box PM performed?
The L-Box PM needs to be performed only once per machine. We advise to do it as soon as possible. Work out with your team leader and customer to find the best possible schedule.
Where can I find information about the L-Box PM?
The information about the L-Box PM is available on the TechPlanet! Follow the link if you are online or use your TechPlanet! CD if you're offline. The L-Box PM procedure is also part of the kit. A PDF file with the procedure is also available on the TechPlanet! Print it you want to read it offline at your convenience. We have 2 kits, one for the 24 diodes L-Box and one for the 48 diodes L-Box. The kit numbers are: FCO 510F27936 and 510F27936A respectively.
Why is it called L-Box PM and not L-Box FCO?
We call it L-Box PM and not L-Box FCO because we want to prevent a problem in the L-Box. An FCO usually fixes a problem. In our case once the problem occurred there's no fix. We can only prevent the problem from happening.
How many L-Box PM were performed so far?
So far we've performed 200 L-Box PM worldwide. This information is valid for the 31st of March 2002. We are shipping 50 kits per months, which is about our install rate worldwide.
Are there any known problems with the L-Box PM?
There are no known problems with the L-Box PM. We encountered a few problems with the first installations and we corrected the procedure. Since then we installed more than 200 kits without problems.
Do I have to return the removed parts?
No you don't have to return any parts. We calculated the cost of returning the parts and decided that it was not economical to do so. Since only one board can be refurbished it doesn't make sense to return it all the way to Israel. It is cheaper to manufacture a new one. Keep in mind those boards are passive, i.e. they include only connectors and thus are relatively cheap and cost around $70. As a general rule we never return boards that cost less then $150. This rule applies in our case as well.
How do I know if the L-Box PM has already been performed?
First of all read the installation procedure, it is written there (another good reason to read it). Second, Look for the label "C" on the L-Box serial number. It indicates that the PM was done.