I was doing something with foolish in avrdude, ending in me killing the bootloader on my Arduino Pro Micro . The Arduino Pro Micro bootloader creates a USB connection which the user can upload code, however by overwriting the bootloader, the chip no longer enumerates as a USB device and can no longer accept new sketches. Fortunately, I hadn’t messed up the fuse bits, so I can still upload using ISP. There wasn’t much documentation on doing this for a Pro Micro, so I had to look up the data sheets for the chip and trace the Eagle PCB schematics. Fortunately, all of the ISP connections are accessible via the pin headers. I used my USBasp, but any ISP programmer including another Arduino running Arduino ISP should work.
Tag Archives: Repair
My brother recently got an iPod Video off eBay which refuses to keep a charge for longer than 30 minutes. I suspected it was an old battery, and thought it could be fixed by swapping in another one. Once I got the case open, I discovered a burn mark on the back on the hard drive foam, pointing out that there was a blown out component on the main board. Lovely.
Years ago I bought two 160GB Seagate external drives, then at some point I didn’t double check which power converter I was grabbing and the little 12vDC drive got a nice 18vDC over-voltage and it blew out the drive. The loss of the HD wasn’t a huge deal since it was empty at the time, but the USB to IDE converter was now curiously showing up in windows as a “Cypress AT2LP RC58”.
A lot of googling around led me to many sites where they suggested using dbflash.exe to restore the EEPROM, which was suggested to be corrupted. I tried, and the tool was successful in flashing the EEPROM, but for whatever reason now it wouldn’t even show up as a USB device in Windows or Linux! FAIL!
So, after some testing the boards, it seemed that nothing was blown, but the controller has suffered amnesia. I discovered that there was an EEPROM on the board which looked familiar. I removed the EEPROM from the still working unit and read out all the data to my computer, then flashed the failed drive’s EEPROM. After re-soldering everything, the unit came up as something different. I took out the IDE drive, and replaced it with another laying around, restarted it, and tada! We have a drive again.
Interesting to see that the over-voltage killed the hard drive, and blanked the EEPROM, but little else.
We decided to pick up a Zeno Acne Treatment system from eBay recently, due to very good sounding reviews. The device has a tip which heats up to a designated temperature, and you are to hold it to a trouble spot on your face for a few minutes while it counts down. This is all great, but the tips are meant to run out after 45 to 120 uses depending on the tip. Before we ran it completely I took did some searching around on the web, and supposedly there is a EEPROM inside. I carefully disassembled the tip and discovered a 24C01A EEPROM was in fact in there!