Repairing a Bread Board Power Supply

I got this bread board power supply a year ago and only used it a couple times. I was going to use it with my Bread Board Buddy (Stand Alone Arduino) when the ATMega 328P over heated and the LED failed to blink.

I removed the Bread Board Buddy and checked the voltage. It was set for 5 volts and the meter read 13 + volts across a resistor.

I checked the 3.3 volt setting and it read 3.3 volts across the resistor; however when I tested the Bread Board Buddy, the ATMega328P IC was fried.

I checked for faults with my meter and everything seemed to be connected.

Since a bad connection on the ground of the voltage regulator; can make a regulated supply put out source voltage, I made sure the AMS1117-5.0 voltage regulators ground was well soldered.

Still the power supply was putting out 13 + volts, chances are the AMS1117-5.0 voltage regulator is bad.

So I prepared to replace the regulator IC.

Magnifier I used a digital microscope held up with my circuit board holder.

Solder

Soldering Iron

Needle File

Spring Loaded Tweezers

Small Side Cutters

Multi Meter

Breaded Ground Wire to remove excess solder, pieces of braded power cord will do if you don’t have braded ground wire.

I didn’t have AMS1117-5.0 voltage regulator; but since an LD50 voltage regulator is virtually the same, I used the LD50 regulator.

You can check SMD (Surface Mounted Device) here:

http://www.s-manuals.com/smd

I started to remove the AMS1117 IC by cutting the three leads with a needle file; if you try to cut the leads with side cutters, you can damage the printed circuit board.

Using the soldering gun unsolder the cut leads.

Then heat the tab and remove the voltage regulator.

Using the braded ground wire and the soldering iron remove the excess solder.

Place the LD50 voltage regulator top down.

Tin the tab and leads of the voltage regulator.

Make sure you do not put too much solder on the tab or leads; if there is a lot of solder on the tab and leads, clean them with the braded ground wire so there is only a thin coating of solder.

Place the voltage regulator in its space; heat the tab and leads until the solder melts and the connections are made.

Last test both voltage selections across a resistor you should get 3.3 volts and 5 volts.

Now you can use the bread board power supply on your projects.