Atmega2560 runs too fast (and hot). Solved

I built an Mega2560 clone and copied memory, flags and bits with AVR studio from a genuine 2560. But the sketch runs too fast. I have a 16MHz crystal like in schematics and I can't see what is on the board. What did I miss. Is it a nasty trick having a wrong value in the schema. 16MHz ->8MHz? Device signature is 0x1E9801 and voltage 5.2V or 5.02V really Fuse registers extended 0xFD, high 0xD8 low 0xFF

lock bits LB = NO_LOCK BLB0 = NO_LOCK BLB1 = LPM_SPM_DISABLE

LOCKBIT = 0xCF (valid)

BODLEVEL = 2V7 OCDEN = [ ] JTAGEN = [ ] SPIEN = [X] WDTON = [ ] EESAVE = [ ] BOOTSZ = 4096W_1F000 BOOTRST = [X] CKDIV8 = [ ] CKOUT = [ ] SUT_CKSEL = EXTXOSC_8MHZ_XX_16KCK_65MS

EXTENDED = 0xFD (valid) HIGH = 0xD8 (valid) LOW = 0xFF (valid)

lock bits LB = NO_LOCK BLB0 = NO_LOCK BLB1 = LPM_SPM_DISABLE

LOCKBIT = 0xCF (valid)

What exactly do you mean by "too fast"? Is the timing a multiple of that expected?

What do you mean by hot?

I had a smitt trigger in reset circuit. Otherwise it was like in original Arduino board. That smitt trigger oscillated which made the CPU act strangely.

Thanks for the update. I'm glad to see you found the issue.