USB HOST IAP with The same project of "STM32F105_107_AN3354_FW_V1.0.0" and exactly the same peripheral circuit(25MHz oscillator), it succeeded by using STM32F107VCT6, but failed by using STM32F107RCT6. Please tell my why, it makes me crazy�?

[fw_it]

[waclawek.jan]

Crystal cube said nothing here.

Using the same USB FLASH stick? They are not created equal.

Checked all hardware connections cable-to-processor-pin for bad solder joints and/or shorts?

Did you attempt any debugging of the software?

JW