Unable to output data and failed to flash the board. (53L8A1)

[lyshengtr]

The device does not output the data in a sudden. And it has no effect to press the RESET button. When I try to re-flash the board, the available memory of the flash only remains 8KB. Even the total memory is only shown as 32KB on PC, much less than the normal size which is 512KB. So I cannot copy the BIN to the flash according to the USER-MANUAL as usual. How to fix this?

[John E KVAM]

When you plug in the STM32 F401RE you should see a disk in your explorer. Right clicking on properties should give you this:

This is NOT the STM32 you are programming - but the debugger interface. 

I've seen your issue. And I'm going to guess you moved a jumper. 

Make sure both ST-LINK jumpers are installed. These are near the silver osculator. 

If you don't have then installed the properties look like:

If this doesn't solve the problem, order a new one from Mouser or Digikey. They are only $10 - plus shipping unfortunately. 

Then you can compare the new one to the old one and look for differences. 

- john