Burnt Resistor
My brother has an old LED sign that he has had for years. It advertises his business and phone number as the LED letters scroll by. It finally stopped working after years of non-stop working, so he asked me to take a look at it. Since I am the know-it-all fix-all Jack of All Trades, I decided to give it a shot.
1 if 3 internal power supplies
The LED sign came with 3 internal Power supplies that when plugged in, convert the 110 VAC into 5 volts each to power 1/3 section of the LED sign each. Since the first one of these power supplies also powers up the "brain" of the LED sign, without it the whole sign is dead. When I checked the power supplies, it was the first one that was not working so when I took a working one and placed it as the Power Supply #1, then 2/3 of the Sign now lit up, and the letters began to scroll.
Upon closer inspection of what was Power Supply #1 showed that a resistor had burned out. The rest of the unit looks in working order. So now the question is what size is this resistor. The burned one is no use because the heat discolored the colored bands around the body of the resistor which help indicate the type of resistor it is.
So the image above shows a good resistor with the colored bands photographed from one of the good working power supplies. Since I am no expert, I believe this resistor to be a 10K Ohm 5% tolerance 1/2 watt Metal film resistor. The resistor is on the 110 VAC power in side. This is the one that needs to be replaced on the bad power transformer.
Of course I will not hold anyone liable for any help they attempt to give. Ultimately the decision will be mine on which resistor I try, but some expert opinion or know how would be nice. I have looked at the wiki site that shows the different sizes and watts of the resistors, and I believe that the color bands are Brown, Black, Orange, and Gold. I am least confident on the Gold color, and then the orange. I am very confident in the Brown and black band color assessment.
Based on this, I thus believe it is a 10k Ohm 5% 1/2 watt metal film resistor. I will wait a few days before ordering the resistor to see if there are any electrical engineers or electronics experts here on Steemit that could at least offer a little guidance. Or if any of you know someone with the smarts to help with this, please let them know about my little dilemma.
The manufacturer of the LED sign no longer makes or sells parts for this unit. Should this fail to fix the power supply, I do have a work around in mind.
