Tag Archive: Electronics


As of spring of 2013, I’ve seen hundreds of Westinghouse solar lamps (item number 577105-08W) being sold at my local Wal-Mart for .97 cents apiece. The value of the components (battery, solar cell, LED) well exceeds the cost of the product, so I decided to pick up a few of them and see how well they perform.

When night fell, I noticed that the Westinghouse lamps were not as bright compared to my existing lamps, and for .97 cents, I really shouldn’t complain. I removed the light cap from the Westinghouse and from one of my existing lamps and laid them side by side for comparison. Both lights were outputting the same brightness. When holding the Westinghouse lamp over my existing fixture, the brightness was comparable to the other existing lamps that I had in my yard.

I believe I had the same problem with my existing fixtures when they were new. What happens after a couple years is that the plastic lens deteriorates from being in the hot sun. When it does, the lens develops a foggy look. The fogginess of the plastic acts as a diffuser and evenly distributes the light in all directions. LED’s shine in one direction, and that direction is down when used in most solar lighting applications.

So what is this all coming down to? Well, if you read my post about the Compaq Presario Power Light, you already know that I placed a piece of matte finish Scotch tape in front of the extremely bright power light to act as a diffuser. So why not try it with the Westinghouse solar lamps and see if it helps improve their visibility.

The lamps have a small amount of “neck” below the LED. This neck is perfect for applying some matte finish Scotch tape around it. I wrapped the tape around the neck twice making sure the tape completely covers the LED. (2/3 of the tape should cover the LED). When done, the tape resembled a straw with a LED in the middle. All I had to do now was wait until nighttime.

westinghouse_lamp_1 westinghouse_lamp_2

The tape definitely helped, and the light looks brighter and can be seen from farther away. I was happy with the results, but the bottom-half of the lamp was still not well lit. I decided to improve the lamp by adding a straw inside the lens in order to help carry the light towards the bottom of the lamp. What I used was a clear wide straw from a fast food restaurant. (The Arby’s straws seem to work the best). I measured and cut off about 1¾ inches of the straw and then wrapped matte finish Scotch tape around the entire length of the straw in sections. Then I used some tape to hold the straw onto the base of the lamp, just below the LED.

westinghouse_lamp_3 westinghouse_lamp_4

When night came, I was surprised at what I saw. Although the straw allows some light to reach the bottom of the lens, it does give the lamp a cool fade effect, kind of like a flame. The straw makes the solar lamp look almost like a bug zapper with a long thin line in the middle of the lens. Overall, the modifications were worth the time and effort.

westinghouse_lamp_5 westinghouse_lamp_6

Advertisements

My RCA L37WD12 TV (possibly the worst flat screen TV ever made) started having problems powering on one morning. After pressing the power button, the TV would display the “one moment please” message and then the picture would appear as usual. At that point, the message didn’t disappear like it should and the TV wouldn’t respond to the remote or the front panel buttons. The only way to turn the TV off was to pull the power cord out. Eventually the problem got worse where the TV would shut off or freeze (sometimes with glitchy graphics) whenever the TV was turned on and the “one moment please” message was displayed, never completing its power on routine.

I traced the problem to a small capacitor located on what someone on the Internet called a standby board. Covered by a RF cage, the main power cables go to the standby board first before going to the main power supply. Replacing the 470uF 16v capacitor (CP616) on the standby board fixed my problem and the TV has been powering on successfully since.

You might also want to check the capacitors on the main power supply if you are having a power related issue with these models. I found 4 bulging capacitors (3 1000uF 35v and 1 1000uF 16v) on my main power supply. I actually replaced those capacitors first, but it didn’t fix my problem until I replaced the one on the standby board. Although the capacitors on the power supply still worked, it would have been a matter of time before they needed replacement.

Update 12/12/2014: The TV recently started to act up again. About a month ago, I turned the TV on (cold start) and all I got was a flashing green light followed by a flashing backlight. After turning the TV off and back on again, the TV powered up without any sound. After the third attempt, the sound came back and the TV worked correctly since then. After Thanksgiving, the sound (again) would not initialize on a cold start and required turning the TV off and then back on for it to work. On December 8, the TV would not come on at all and started flashing the green light and backlight again. I took the TV apart and found that one of the capacitors that I did not replace on the main power supply was slightly bulged. (The bulged 1000uF 16v capacitor measured ~150uF on the ESR meter!) After replacing the defective capacitor, I reinstalled the main power supply only to find that the new capacitor did not solve the problem. I checked all the capacitors with the ESR meter and all appeared to be good. Today I read on the Bad Caps forum that faulty capacitors can be revived temporary by warming them up. So I took the main power supply back out, placed it near a furnace vent and reinstalled it when the furnace turned off. To my surprise, the TV came on without a problem, so I still think that there’s a capacitor at fault somewhere on the main power supply. When the TV fails to power on again, I will use a hair dryer to heat up individual capacitors and find out which one(s) are at fault. It could possibly be one that I originally replaced and I wouldn’t be surprised since the TV is on almost 12 hours a day.

Update 12/14/2014: I found the faulty capacitor! It’s the 150uF 450v AC filter capacitor and it’s only reading ~78uF on the meter. Warming the AC filter capacitor up with a hair dryer on low speed/low heat for 5 seconds was enough for to TV to power on correctly. When the TV cools down and the AC filter capacitor discharges, the TV would fail to turn on. I’ve done this trick 4 times already and it works every time. I currently don’t have an exact replacement in my collection of capacitors, so it looks like I have to buy a new one online.

Update 7/28/2015: I finally got around to replacing the 150uF 450v AC filter capacitor. The TV powered up correctly after installing the new capacitor. But when I went to turn it on the next day, the flashing green power light and backlight was back! The results are somewhat different with the new capacitor. There are times when the green light would start flashing when the backlighting activates. Other times the symptoms are the same as before the replacement. The biggest difference is that the light will now stop flashing after several seconds and the TV may try to successfully power on. If the TV locks up, turning it off and back on is usually enough for it to successfully power on. I think that the other capacitor (10uF 400v) next to the AC filter capacitor needs to be replaced as well, but I do recall checking it with the ESR meter only to find that is was OK.

Update 8/11/2015: I installed the replacement 10uF 400v capacitor on the power supply. The TV successfully powered on with no problems. The next day, you guessed it, the power light and backlighting started flashing again. Warming the power supply up with the hair dryer brought it back to life. I am out of ideas as this now appears to be something other than a capacitor. All major capacitors have been replaced on the power supply and all off them are known to be good. If anyone has any ideas on what could be the problem, please let me know in the comments. At this point, it looks like a replacement power supply is the only thing that will fix my problem. However, new ones cost as much as what the TV is worth and used ones are likely going to have bloated capacitors which will fail soon or have already failed. Warming up the power supply with the hair dryer is the only feasible way to keep the TV running until that method no longer works or until something major breaks. I was hoping to keep the TV until the backlighing burns out.

Update 3/19/2017: Well I think I finally found the little bugger! I took another look at the power supply and tried isolating the surrounding capacitors by blowing on them through a drinking straw until the TV successfully turned on. At first I thought I found the bad capacitor, located at CS26 (680uF 16v), but replacing it did not fix the problem after the TV cooled down. I kept thinking the problem was with the 10uF 400v capacitor that I already replaced, so I went ahead and bought another one off of eBay. To my surprise, the replacement capacitor did not fix the problem. I then preceded to experiment by installing both the 10uF 400v capacitors together in parallel, with the one capacitor soldered on the board and the other routed away from the power supply. This gave me a total of 20uF. (Normally you shouldn’t do this, but a small increase in microfarids shouldn’t hurt anything.) While the additional microfarids didn’t create any undesirable operation, the TV still continued to have problems turning on when cold. I took the hair dryer and tried warming up the capacitor that I routed away from the power supply. To my surprise, the TV did not want to power on, which told me that these 10uF 400v capacitors were not the problem. I returned to the drinking straw method and for the heck of it, checked a tiny 10uF 50v capacitor located at CS44, next to the 10uF 400v capacitor. After blowing on it a couple of times, the TV started up successfully. After turning it back off, I waited for 15 minutes and tried turning it back on again, which at that point failed to power on. I blew on that same capacitor again, turned on the TV, and it started right up. I went ahead and replaced that capacitor with one of the same value from a salvaged DVD/VCR player. I waited for a couple of hours for the power supply to cool down and the capacitors to discharge. I powered on the TV and guess what… IT SUCCESSFULLY TURNED ON! That tiny 10uF 50v capacitor which I never suspected to be the problem, was the culprit! It gave me the runaround and made me replace capacitors that weren’t even bad. It just goes to show you that even the smallest of all capacitors can fail also, even if they don’t show signs of failure.

Update 2: Well I don’t know what the heck happened, but now the TV is completely DEAD! I turned it on the next day and it successfully powered on. I later turned it off and back on again and the TV came back on. I then turned it off to clean the screen, and upon turning it back on, the green light flashed a few times and… that was it. No more green light! The TV still turns on/off with the remote and the front panel buttons, but the green light does not come on and nothing happens. The hair dryer doesn’t even help revive the power supply. I have no idea what crapped out on the power supply. I’m not going to buy a used one on eBay as they are a bit overpriced and likely need to be re-capped. I am done trying to fix this TV and it’s probably going to be sent to the recycler.

If you’re like me, you probably like to save and collect those LED lights from your old electronic equipment before you toss it out. But how do you know what type of LED it is? How do you know what color the LED is? How do you know if it works? You can create a small unit to test LED’s with some parts that are probably lying around in your house. Here’s what you need…

  • 1 battery case that holds two AAA Batteries (Radio Shack No. 270-414)
  • 1 resistor (Suggested: 39 Ohms – Orange, White, Black, Gold)
  • 1 two pin female connector plug (a plug from a computer fan works well)
  • Heat shrink tubing

You will also need wire strippers and electrical tape. You probably might want to use a soldering iron to solder the wires onto the resistor. I just twisted the wires on the resistor as the heat shrink tubing will help hold the wires in place.

The battery case will hold two AAA batteries totaling to 3 volts. Because fresh batteries may contain a little extra voltage, you will need to use a resistor to protect the LED’s from damage and failure. I recommend a 39 ohm resistor with an orange, white, black, and gold stripe in that order. This will step the voltage down to roughly 2.8 volts and will help maintain the brightness. You may use a resistor of a different ohm value, but the LED brightness may be dim.

The connector on the other end makes it easy to insert and remove a LED. The connector will hold the LED in place and will not fall out.

  1. Slide some heat shrink over the wires on the battery case, enough to cover the resistor when you are done making connections.
  2. Connect the positive lead from the battery case to one end of the resistor.
  3. Connect one of the two wires of the connector plug to the other end of the resistor.
  4. Connect the other wire of the connector plug to the negative wire on the battery case. Use some electrical tape to cover the bare negative wires.
  5. Slide the heat shrink over the resistor and the joined negative wires. Before heating the heat shrink, install the batteries and make sure the circuit works. If the LED doesn’t light, remove the LED and turn it around. Because a LED is a diode, it will only work one way. If the circuit works, remove the LED and batteries and heat the heat shrink.

There you have it! A portable LED tester that’s small and convenient.

Outdoor LED Solar Lamps

You may have notice your local Wal-Mart store selling those small outdoor LED solar lamps for about $3.00 a piece. You can’t beat that price since the rechargeable battery, LED and solar cells included in the lamp probably cost more than its price tag. We bought several of these lamps and so far we’ve been pleased.

If you don’t know how these lamps work, here’s a short description. The lamp charges a rechargeable battery connected to a solar cell located on top of the unit. As night falls, the lamps are automatically turned on by a photocell. When morning arrives, the lamps automatically turn off.

Don’t expect a whole lot of light since the lamp only contains a single white LED and one rechargeable nickel-cadmium AA battery.  Although noticeable from across the street, the lamps are useful for marking a walkway or just adding light to your yard or garden. Because the lamp contains one LED, the lamp may not provide enough light to light up the ground.

The rechargeable battery will last for a few days in cloudy weather. If the lamp is located in a constantly shady area, the battery may weaken and turn the light off in the middle of the night. This also brings me to the point on how well the solar cell recharges the battery. After popping out the 1.2 volt rechargeable battery and attaching a multi-meter to the lamp, I discovered that the solar cell puts out between 1.6 – 1.8 volts to the battery when it is in the shade. After moving the lamp into full sun, I found that the solar cell outputs a maximum of 2.2 volts to the battery, enough to recharge the battery if the lamp constantly receives full sunlight. During cloudy weather, the solar cell will charge the battery enough to last a few days if conditions persist.

The nickel-cadmium batteries can be replaced with nickel metal hydride batteries, which will give you better performance and will last longer from constant recharges.

In conclusion, you get a good deal with these outside solar lamps. The lamps will provide you basic all night lighting when installed in locations with continuous full sun lighting and a good quality nickel metal hydride battery.