Help with burning to an SST27SF512

[zspanners]

Plus the read back as requested.

Thank you.
zspanners

[Jayme]

zspanners compare.JPG

this is the problem. these bytes are different after the read back. if you go into windows calculator and type in the hex in the left, then toggle bit4, then you get the answer in the right. it means all of these errors are because one pin is not connecting properly from the chip to the burner during the burn. either the chip is buggered, or a pin is dirty in the burner.

also your stack is 512kb... it should be 64kb as per holden202t's top screenshot.

[zspanners]

Hi Jayme , thank you .
I will have a look at the pins and re-read the bin from the MVRAM.
Then try to re stack from there.

Thank you.

[Jayme]

nah your read from the nvram is good! its just the burn back to the 27sf512 that is failing due to one unconnected pin. perhaps try a different 27sf512 first?

[zspanners]

Hi Jayme , thanks will try that tomorrow morning.
zspanners.

[j_ds_au]

If it's a pin, it's pin 15.

Joe.

[zspanners]

Hi Guys , thanks for the assistance.
Turns out to be a whole batch of faulty SST27SF512 chips WTF.

Now all sorted with an old stock chip that i had squirreled away.

Thank you.
zspanners

[j_ds_au]

Hi Guys , thanks for the assistance.
Turns out to be a whole batch of faulty SST27SF512 chips WTF.

Now all sorted with an old stock chip that i had squirreled away.

Thank you.
zspanners

Wow!

Two thoughts :

- Maybe fake chips.
- Maybe programmer issue.

If you're local, I can check them for you.

Joe.

[Holden202T]

yeah were they purchased from ebay ?

I wouldn't think its a programmer issue if the spare one works.

[j_ds_au]

yeah were they purchased from ebay ?

I wouldn't think its a programmer issue if the spare one works.

Yeah, never buy popular chips from SEA, be it via eBay or wherever. So many fakes!!!

Reading at Moates' site, the fakes are OTP, which can't be erased, yet here we have some bits that have failed to program (opposite problem). BTW these chips today (the genuine ones) are made by Greenliant (they are not obsolete).

Too short a programming time, too few programming overburns, incorrect voltages, insufficient current. All these could make a programmer unreliable with some chips. Had similar issues years ago programming M38207E8 microcontrollers.

Joe.