on the cable.
That last one is actually one of the ones I mentioned.
In any event, the jumpering is shown here:
http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1542&p_created=#jumper
To run this drive as master with your other drive on the same IDE
cable/channel, the WD5000JBRTL needs to be jumpered as "Dual Master"
with the other drive jumped as "Slave" or "Dual Slave" (whatever they
call it) per its own jumper specification.
The "small gap" does sound like a cable-select cable but I would be very
wary of anything from someone's "junk" drawer when you are already
having problems. If you were originally running a master/slave system, I
would buy a new, regular cable at a computer store (rather than Best Buy
etc) - it should only cost a nominal sum. Then set up the jumpers correctly.
If you do want to pursue cable select, it might need a change in the
BIOS setup .... some systems can do it without, simply by using the
appropriate cable; some need to set it in the BIOS as well I think.