Re: Cpq Presario 906

Am 29.04.09 13.38 schrieb BillW50:
In news:nvPJl.83300$Ji5.65283@xxxxxxxxxxxx,
Wolfi typed on Tue, 28 Apr 2009 22:06:57 -0500:
Am 28.04.09 15.36 schrieb BillW50:
In news:_tJJl.109201$e_5.38992@xxxxxxxxxxxx,
Wolfi typed on Tue, 28 Apr 2009 15:15:52 -0500:
Am 28.04.09 11.46 schrieb BillW50:
In news:L%FJl.89839$9t6.87607@xxxxxxxxxxxx,
Wolfi typed on Tue, 28 Apr 2009 11:18:49 -0500:
Am 28.04.09 07.48 schrieb BillW50:
In news:bZvJl.56984$g%5.22327@xxxxxxxxxxxx,
Wolfi typed on Mon, 27 Apr 2009 23:53:27 -0500:
I recently acquired a used Cpq Presario 906US 470047-897 laptop,
which comes w/o the internal FDD.

Since it offers to boot from floppy in the BIOS (V. 0F.0B) and
also has the 26-pin flexprint floppy connector on the mobo, I
now got a matching palm rest with FDD (P/N: 285539-001),
because I want to install some s/w, requiring to be installed
from a FDD.

However during POST or later by any OS the FDD is not recognized
at all.

Does anybody know why and how to fix it?
Buying a $15 USB FDD should do the trick. Best of all, it will
work on any computer that supports USB booting.

I know, but I wanted to avoid needing an additional external
device only causing more clutter and sucking power out of only 2
USB ports, which are occupied already by other devices.

I just can't get my mind around, why and how Cpq would disable
something such essential and simple as a FDD controller, when
everything is already readily available on the mobo :-\
Oh I see. I bought one just in case I ever need it. But I haven't
needed it yet. I did test it and it does work great though. I don't
know why Compaq would disable the FDD port though. <sigh>

Say do you have a PC Card slot free? If so you can buy (for about
10 bucks) a PC Card to USB card. My card adds four more USB2
slots. You can't pull 500ma off of all four ports at the same time
though. About 800ma max from all ports. You can get more with
another source of power.
Not anymore, since the only one being available is already used for
just that purpose ;-)
In my case with a slim @× USB 2.0 adapter which up to some 3mm
leftover completely disappears inside the slot, that doesn't work,
since it only provides 100mA per port. This is actually a limitation
of the CardBus connector itself, which apparently only has 2 5V
power pins, designed for no more than 500mA each. So with the
adapter sucking up power it apparently doesn't leave more than a
total of 200mA distributed to the 2 USB ports.
I already diverting power from the PS/2 mouse/keyboard jack to the
external power-in of the USB CardBus card, but so far HP/Cpq failed
to tell me, how much current can actually be drawn out of this PS/2
jack. I doubt that it is more than 500mA total, if at all.

For all those reasons I thought it to be the smartest way to go,
having the FDD sitting inside as it used to do from the beginning of
time (in mobile computing that is ;-) ), but of course would have
never expected Cpq doing such a lot of BS in order to make life so
miserable for no apparent reason at all.
Well be very careful of drawing power from the PS2 port. I say this
because many of them are fused and once the fuse goes, you now have a
motherboard repair job (or left with a dead port). And I thought PS2
provides only 150ma max.

I was searching for that spec for quite a while, but came up with
only 2 articles. One was kind of generic and talking about up to 1A in
desktops, the other one, which seemed to be more reliable, was stating
275mA. In the case of this combined mouse/KB jack, one would assume
the power carrying pin #4 would be able to provide 2× 275mA, but who
knows where and how Cpq botched here as well.
Aren't PS/2 ports protected with polyswitch fuses as well? HP/Cpq
still owes me the answer to that question.

Well you could be right. As I am going by some webpage I read sometime
ago.

The PC Card slot is allowed 850ma of power by the specs. And the
protection is resetable. So if you draw too much, the power should
come right back once the load is removed. Same is true of USB ports.
Mmmh, according to the sources I found, it was talking about 2 power
pins in the CB connector, designed for 500mA each and limiting power
leaving the CB card to a max of 200mA, if no additional external power
source is being used.

Again you could be right. As I can't be sure of my source anymore.

My PC Card to USB sticks out, so I don't have the tight quarters
problem.
I was actually specifically looking for one, that doesn't stick out.
And in your case with 4 ports, providing external power is even more
important than with my 2 ones, if you plug in anything other than pure
data cables.

Well mine came with an extra cable to plug into an USB port to draw
extra power. Hard to say how much power it supplies. Since the laptop
(the Gateway MX6124) I use it on has four USB2 ports for a total of 2A.
I don't know if I can draw 2A from one port alone or not.

According to the specs it shouldn't be possible. Actually only devices
that log-in with the USB controller shold get up to 500mA, if they
request so. "Dumb devices" like a Y-splitter plug or those, that don't
log themselves in, should be granted only 100mA. This would mean, that
strictly according to the specs, the max current any device should be
able to get out of a USB port would be 500mA + additional 100mA from its
Y-splitter connector.
In reality however, they usually can draw up to n×500mA (with n being
the number of available USB ports having their power line connected to
the same source on the mobo).
I was already wondering why on hubs, my USB CB card and on some USB PCI
cards the USB power pins and the external power jacks where all
electrically connected directly, w/o any circuitry in between to
accomodate for that USB "power management' the specs tout so loudly.
Basically no one gives a rat's but about implementing it.

The biggest draw device I have my USB slimline DVD burners. On the
Gateways, I haven't noticed any problems. Although I never tried them on
the PC Card / USB ports. On the EeePC machines, big problem! While it
sports two USB cables, hooking the first one up causes the netbook
(these has three USB2 ports) to drop power for a split second (which by
the spec isn't supposed to happen). Thus everything is lost and it
reboots. If I connect it up with the netbook turned off (it still has
power on the USB ports if on AC power), I have no problems. I don't even
need the second USB cable for extra power either.

In an online article about USB burners I just read the other day, the 4
models they tested drew peak currents from around 950mA up to a bit over
1.3A and averaged at around 700-800mA. So strictly according to USB
specs they could never work on any 2 USB ports (500+100mA) w/o having
additional external power.

As for my PC Card / USB card, I can without external power use one big
USB draw without problems. If I have two big draw devices (like two SD
card readers), the power will drop and the devices won't work correctly.

Yes it is a shame how Compaq designed it. <sigh>
I was therefore hoping to find someone here in this NG, who was
already able to solve the problem with the not-detected FDD, because
it really doesn't make any sense.

Well my wild guess it is locked out in the BIOS. But it is just a guess.

And that's just the thing, this BIOS version is used for models which
came with the floppy from the very beginning, as well. This again leads
me to suspect some major BS being done on the h/w level, but then again,
why adding the floppy connector in the 1. place (could have saved
another 2 and 11/47th cents).

It's just so frustrating if, after cumbersomely eventually getting
everything, for no good reason at all, what was expected to be
functioning then so obviously, some intentional BS implemented by the
manufacturer then kicks you in the nuts just once again.
.

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