21 Dec
2007
21 Dec
'07
1:29 a.m.
Jos Dreesen / Marian Capel wrote:
Brent Hilpert wrote:
.. try swapping two 9016 chips on the one memory board to see if
the problem moves with the chip? (or are the chips soldered in?)
Jos Dreesen / Marian Capel wrote:
It is a three power device, all voltages are there. The IC is part of the Lilith memory,
which are 4 pcb's with 32 x amd9016 devices each. 16 bit wide for r/w, 64 bits wide
for instruction fetch and video output.
The machine functions, but the defective IC shows up as a white stripe on the display
since it is part of the video frame buffer. Changing the IC did not help, of course also
the 4116 replacement I used could have been defective.
The graphic board is OK, since (WARNING : board swap !) using another memoryboard solves
the problem.
I ordered some exact replacements and will continue when they arrive. Suggestions as to why replacing said am9016epc
with a mcm4116bp20 does not work,
are also welcome.
Should have mentioned this previously, but are all the power supplies there?
The info I have says the MCM4116BP20 requires +5,?5,+12. It isn't clear as
to what the 9016 requires but there are other 16K*1 DRAMs listed as requiring
only +5.