Reverse engineering of BK Precision 1696 switching power supply’s LCD protocol

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Kerry Wong writes:

As mentioned in my previous post, besides the broken LCD there was also an issue with the power supply portion of the unit and the output voltage was clamped at around 10 to 11V. The digital circuitry portion however seemed to be intact. Unfortunately since an identical LCD is virtually unobtanium, I thought I’d reverse engineer the LCD protocol so once the power supply is fixed I can fix the display by hooking up a different LCD.

See the full post on his blog.

Check out the video after the break.

Teardown of a BK precision 1696 programmable switching power supply

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Kerry Wong did a teardown of a BK Precision 1696 programmable switching power supply:

My original plan was to find a replacement LCD and restore the unit to its original full functionality. But the LCD used in this unit is likely specifically made for the 169X series of power supplies and through some initial research I realized it would be extremely difficult to get hold of unless I could find a donor unit with a functional LCD inside. After I received the power supply, I realized that it had more issues than just the broken LCD itself. During my initial testing, I found that the output would not reach higher than 10 to 11 volts even with the over voltage protection set to the maximum value (20.5V). So clearly I have more homework to do, and for the time being let’s simply strip it down and see what’s inside.

See the full post on his blog.

Check out the video after the break.