> Is it possible that EEPROM up to 30% of the PIC:s is bad?

Oh no, not another "There's a bug in the compiler because my perfect
program won't run" lament!

An EEPROM problem in the PIC is very unlikely.  Don't waste time
suspecting the PIC until you are to a point where you can *prove* it's the
PIC.  Without solid proof, nobody is going to believe you anyway.

> This week I got my PCBs from the PCB house and programmed the PICs with
> my bootloader and the actual software. Everything ok so far, but when
> trying 10 PICs, 3 of them didn't work.

Sounds like a bug in your code to me.  You haven't said anything to prove
or even suggest otherwise.

> My bootloader reads the last EEPROM-byte and if it's 0xFF it goes into
> bootloader mode and if it isn't the normal software starts.
>
> I found out that these 3 PICs that didn't work leave in bootloader mode.
> I did suspect that the EEPROM byte wasn't cleared the first time the
> actual software started but 2 of the 3 PIC's did actually work about 30%
> of the time.

And you still think the EEPROM is at fault!!!?

> One solution for this problem would be to read that EEPROM two or three
> times and compare, then there would be (hopefully) only one that didn't
> work.

Argh!  Voodoo programming is never a good idea.  You might as well wave a
dead fish over it during a full moon.

> But the biggest question is still: Should I be worried that the other
> EEPROM bytes doesn't "read right" sometime??

You need to assume you've made a mistake in your EEPROM read and/or write
routines.  Only then will you be able to find and fix it.


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