um. im not terribly sure how you check tbh
put the sata card in, and a drive on it ,then check in bios for the boot order and see if the new drive appears as an option in it i guess is one way to check
One last resort would be to use the big pata drive as your primary boot ( ie you have windows installed on it ) and use the sata drive as storage.
thats one way to do it i guess
What sorta quality is the extention lead? that might be another cause for the signal dropping off ( which is what i presume is happening )
Typically, the gain on bt lines allows for 4 devices. Splitting the line decreases this .
each filter actually splits the line, as well as filtering it; therefore having lots on the line is unnecessary
Some modems / routers let you see all sorts of techy info about the line. for instance on my line, my router says :
ADSL Firmware Version: 4.01.00.00 - 1.01.00.00 - 1.01.00.00 Annex A - 01.06.06 - 0.49
Line State Connected
Modulation Multi-mode
Annex Mode ANNEX_A
Max Tx Power -38 dBm/Hz
Item Downstream Upstream Unit
SNR Margin 31 31 dB
Line Attenuation 16 16 dB
Data Rate 576 288 kbps
What precisely that means im not -entirely- sure. the Line attenuation i recon is the amount the signal is being degraded on the line, and the SNR ratio ( signal to noise ratio ) is how strong the signal is
If you can see similar techy info on your modem/router, have a look at the SNR ( if possible )
if its too low, then either the gain is too low, or the cables are crap