18 Sep
2004
18 Sep
'04
1:52 p.m.
At 02:17 PM 9/18/2004, you wrote:
As I stated earlier, I have cannibalized three HP
laserjet series II
printers. In looking over the parts recovered I find that I have three
(3) totally different memory boards.
The first is populated with small chips on BOTH sides of the board with a
total of 128 soldered in chips that appear from their part numbers to be
256K memory chips, That is the number 256 appears within the part
number. Now I don't know how wide the buss is but I am assuming 8 bits
because of its age. If so this board is a 4 Megabyte memory board.
um, that sounds probable...
The second is only half populated with 16 soldered in
chips on one side
that have the number 1000 in their part number so I am assuming they are
1meg chips and using the afore mentioned logic I come up with a
2Megabyte memory board.
yes, that's a 2meg board using 1 megabit chips
The third is fully populated with 32 socketed chips
with the number 1000
in their part number and that works out to a 4 Megabyte memory board.
yes, that is a 4 meg board.
Is my logic sound?
Do I have two 4 meg boards and a 2 meg board?
What is the largest memory board the Series 2 could hold?
4 megabyte
I am assuming that the socketed memory is best because
it is easily
repaired, but are there any problems with the socketed memory having bad
contacts after time?
the biggest problem I've had with laserjet boards is the PALs and GALs they
used on some boards (HP and aftermarket) for addressing failing over time :(