Page 19 of 31. Version 1.03 September 2012
Microbee Premium Plus+ | Construction Manual
Speaker wiring
The speaker should already be in place in the bottom of the case held in with its metal
clamps & screws. Wiring is straight forward with the 2 core bell wire supplied. Strip both
ends of the wires, tin them with the soldering iron and attach to the speaker and baseboard
as shown in the photos below. The volume control for the speaker should be set at the mid
way point of its travel now.
Tinned Bell wire attached to the speaker
Speaker cable connected to the under-side
of the PCB near the 5 pin DIN socket.
9. Final checks & first power up.
Now that all the components are soldered into the baseboard, it is time for final visual
inspections, checking for shorts and un-soldered pins, component orientation mistakes,
polarised capacitors & diodes the wrong way around and so on.
The check that was carried out earlier with the multimeter can be done again in checking for
a short across the input power rail at C71, not that much should have changed in that area
since the previous check. It is however a simple test & easy to carry out, so best to do it
anyway. The voltage checks can also be done, without the coreboard installed, to ensure
that the two 5 volt power rails still provide the required voltage.
Without the coreboard plugged in, the system will not do anything, so don’t expect to hear a
beep or get video on the display – we just want to measure the power rails again.
Once done, remove power from the baseboard.
If all looks good, the coreboard can be plugged into the baseboard. Make sure that the 25
way pins strips fit snugly into the baseboard sockets and pin1 goes to pin 1 (that it hasn’t
‘missed by 1’). Also make sure that the 2 pins hanging down from the coreboard near the
SDcard socket are properly inserted to the 2 way socket on the baseboard. If these 2 pins
do not meet with the socket properly, the Coldfire processor on the coreboard will not be
able to get the machine up & running properly and will have no way of gaining control of the
baseboard signal busses. Leave the SDcard out of the socket for now – it is not needed until
the after we see video output & run the in built self test diagnostics.
