From: robotnz1000 on

Hi all,

I am trying to work out what information is in these head eeproms, to
try to get ideas on why the heads either work or don't.

I can read and write the ink chips for 6200 - 8200 which have the same
IC model. 93LC46. Though the head eeprom is the slightly bigger 93LC56.

I can read the eeprom OK. Indeed the head pcb while only a very light
weight fibreglass PCB it can be lifted off the plastic rivetted pins
quite easily with a break off tip knife and pried open enough to get a 8
pin IC probe clip onto the IC. This still leaves the head usable if it
is a good head.

So I started with heads known dead or expired and read several, first a
w6200 model BC-1450, the eeprom was totally erased to all FF's so empty.
Then I checked an expired BC-1400 from a w7200, agin the head was all
FF's, so nothing, totally erased. So then I had more courage and pulled
a good w7200 head, opened and read the eeprom, again all FF's, as in
totally erased. By this time I was getting rather puzzled as to why the
program was gone.

So I pulled an expired head from iPF5000 a PF-01 head, I read it and
again all FF's - so totally absent of memory as if erased.

I have some small but good experience and success reading and editing
and re-writing the 6200 - 8200 ink chips so I know what to look for and
ho to read and edit and write from and to 93LC46 style eeproms.

But still I am baffled as to why all these heads have no eeprom
be it a good BC-1400 or bd 1400/1450/PF-01 they all read empty.

So what does the head eeprom do, how is it used by the printer and when
is it programmed, read and erased???

What I was hoping to see is some style of program similar to the ink
chips which would be readable from a new head and able to be programmed
into a used head for testing. To perhaps see if 'expired' heads could
have their life extended. In similar fashion to extending the life of
ink carts and ink chips by re-writing the chips as an alternative to
turning off the ink monitoring in these printers.

Does anyone have ideas or experience in this regard?

cheers :-)