Barco 808/Cine8

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7) Switched Mode Power Supply (SMPS):

Also called the main power supply.  There are actually three power supplies on this board, the standby one which is on all the time, and sends a low voltage to the IR receivers, the internal keypad and  the controller board . the main power supply will turn on when the standby or power button is pushed, and provides power to all modules. The third supply supplies the H deflection voltage to the horizontal board. This board contains 9 fuses as per the photo.

The switch mode power supply is one of the more common parts to fail in the Barco projectors. All circuits are driven by the power supply, and the unit can run relatively warm.

One adjustment that does drift occasionally is the + 17 volt trimpot. The test point for this trimpot is shown in the picture. Use a meter to measure the DC voltage with reference to the chassis, and adjust for + 17.0 volts*. This adjustment is critical for proper operation. If the voltage is off by more than ½ volt, the picture can blank out.

*Note: If you're reading through these 808 tips because you have a 1208/1209 projector, be aware that the +17.0V trimpot should actually be adjusted to 17.5V (not 17.0V). Setting the pot to 17.0V may cause eventual spotburns.

The last point of interest is the green LED on the sub power supply board. This LED shows that the HTHD power supply section that drives the H output section is working. You will not get a picture if this LED is out, and the power supply must be sent for service.

The main power supply board actually contains two independent power supplies. One drives the entire set, the second one provides the voltage for the H output section and parts of the HV area. The set will not show an image without all supplies working properly.

As per the first SMPS picture, the main 3 amp fuse is located to the left of the supply, and if this fuse blows, the set will go dead. Usually the fuse only blows if the SMPS has a problem in it, replace this fuse ONCE only as a test, and if the second one blows, please contact us for the repair.

To the right of the main board, you’ll find 7 additional fuses. Early supplies had these fuses in fuse holders that look like the main 3 amp fuse holder, the later power supplies have the fuses soldered into place. These fuses do blow on occasion for no reason, again, if you have a blown fuse as measured with a continuity tester, replace the fuse ONCE only with an identical value, if the second one blows, the set has problems. The soldered in fuses may be replaced with similar solderable fuses. I use a type of fuse called a Picofuse. They look a bit different than the originals, but serve the same function.