Tip & How-To about Samsung HLR5067WX 50" Rear Projection HDTV
DLP randomly shutting off
I have found that the back cover switch is usually the culprit. Either it is going bad, or it is on the edge of activating. Usually the second. The main problem is that this blue switch is on the verge of activating and can cause intermittent shutdown of the set.
One way to check for this is to remove the small back cover that is for replacing the lamp. Usually about 6" X 5" or so. Remove this and you will see a blue switch that should be activated when cover is reinstalled.
The problem is that when the cabinet gets hot and expands, the cover expands and moves slightly and causes intermittent shutdown of the set.
IT will drive you crazy. One fix you can do yourself is to put a piece of black tape or double sided tape onto the cover where it contacts the switch and that should solve your problem. I like to make it kind of thick maybe about 1/8" or so as to insure it won't keep happening.
THAT'S IT! reassemble and your finished. And you just saved yourself a service call.
Shine a light on the display at an angle from the side. If you can see part of what is normally displayed, then the display backlight is faulty. If the monitor is more than four years old, it probably uses fluorescent tubes in the backlight, and one of those may be going bad. The inverter detects the failure and shuts down. If you look closely, you may see a pinkish flicker on the top or bottom of the display, and more or less normal color on the opposite edge, or one edge may remain dark. That would be the bad tube. (Some monitors have four tubes, two on each edge, in which case the failed tube would only show as one edge being dimmer than the other.) I generally replace all the tubes at once; that's easier than having to go back in a few weeks later to change another one with similar wear history.
A more probable failure is a bad electrolytic capacitor in the inverter power supply circuit. (The inverter section has pink and white or blue and white pairs of wires going to the sides or corners of the display. The capacitors will be somewhere on the other side of the transformers from the lamp wires.) When these burn out, the top of the capacitor bulges up in a dome shape, and may have some leakage of the contents visible. (Note to other technicians - yes, they do burn out. I've cut them apart and found charring around the center (+) lead.) If you see bad capacitors (there may be several), replace all of the bad ones, then test the monitor.
When choosing a replacement, get one with the same capacitance (uF), the same or higher voltage rating, the same or higher maximum temperature, and make sure it will fit in the space available. Don't get one so long you can't put the cover back on over it! You also want a high ripple current rating and long life type. I usually select the Panasonic FR series capacitors. I almost never use the original brand; that's usually part of the problem. The capacitors must be installed correctly; the "-" stripe must match the position of the original part. There is usually a polarity marker on the circuit board as a reminder. A backwards capacitor will fail prematurely, sometimes with a messy explosion.
Replacement of the parts requires electronic soldering skills. The fluorescent lamps are particularly delicate; you shouldn't apply heat for more than three seconds, and you have to make the connection small enough to get the insulators back on. For that, I use 63/37 tin/lead solder; the lamps are hazardous waste anyway (mercury vapor inside).
This is a common problem. Usually, the fan's RELAY has went bad. This relay can usually be found under the hood, somewhere in the engine compartment.
The relay is just a switch, and is activated by the engines temperature sensor.
It is just a pull-out, and plug back in little black box. usually, it is well labeled, and easy to find. it will be in a box, with a lid, and when you remove the lid, there should be several large fuses, and some little black boxes that usually say BOSCH 30A on them.
If you change the relay, and your fan still does not work properly, then the problem may be the temperature sensor on the engine, the wiring, or the fan itself may have went bad.
But, start with the relay switch, as it is the most likely culprit.
Either the cable connecting the keyboard to the laptop's motherboard has come loose, or the keyboard itself is bad.
You don't give a brand or model so I can't be too specific, but it's usually not difficult to remove a laptop keyboard. On most models you need to remove the plastic hinge covers and trim strip along the top edge. Often these are one molded piece, but on some computers the hinge covers are separate pieces. Look for small screws that may hold the cover down on the back edge or possibly through from the bottom. After removing any screws, the plastic pieces snap off. Be careful not to break the strip or hold-down tabs. Just work slowly and carefully.
With the trim strip off you can see the top edge of the keyboard. On some computers there are 3 or 4 screws holding the keyboard down. Other models have screws that go through from the bottom, and these are often labeled with a K.
Once the keyboard is free, lift it carefully by the top edge and tip it toward you. You'll be able to see the cable that connects to the main board. Make sure it's firmly seated in its connector. Set the keyboard back into place (you don't need to worry about putting all the hardware back yet) and see if the trouble continues. If it's back to normal, put all the screws back in, snap the covers back on and you've fixed your laptop. Otherwise, check online (eBay's a good place) for a replacement keyboard. They are widely available now for most models, and the prices are usually reasonable. Plug the cable from the new keyboard into the motherboard connector and replaces all the other stuff.
It is possible, but not common, that the keyboard controller on the motherboard itself is bad. If that's the case, the only fix is to change the board. That's a job best left for a professional. Replacement boards are available, but can be costly, so if the board is the trouble it may be time to consider replacing the computer. But the keyboard is normally the culprit.
Good luck, and thanks for using Fixya. If this has helped you, please take a moment to give a thoughtful rating.
Fuel injection usually has a high pressure electric pump, which usually runs off a relay so that it does not melt the ignition switch, and so that it is easier to cut out if the bike tips. Relay could be going bad, or there could be a tilt sensor loose or going bad.