December 1 997
wire cable going to the laser. He
said that for what the cables cost,
it is advisable to try new cables
before condemning either the
laser or decoder. We agree.
Many thanks to Albert for this
great piece of advice.
STAR .... TECH jC>URNAL
SOLUTION
SyberSonic Jukeboxes
Check and, if necessary, replace
the 5. 7V regulator and clean
edge connec-
tors.
Also
check the plug
connections
on the Power
Distribution
Assembly for
good contact.
SYMYrOM
ADDITIONAL
RE-
in Non
OccASIONAL UNEXPLAINED
BOOTING OF CoMPUI'ER
Occasional re-booting of the
computers in any non
SyberSonic Rock-Ola causing the
complaint of music cutting out
during a song or lost credits.
ACTION
The logic power should be mea-
sured at an IC on the computer
board itself. Measure across pins
7 and 14 of IC 16 or IC 29 (a
....
"'C
"' 0
co
:::>
~
u
...,j-
0')
u:
74LS04 chip). If the voltage is
less than 4.90, the logic will not
be reliable. This problem can
many times be traced to a bad
5. 7V regulator in the power sup-
ply or extremely dirty edges and
connectors on both the computer
and power supply.
Allcomputers will work properly
from 4.90 to 5.10.
INFORMATION
The regulator
circuit is actu-
ally designed
to produce 6.2
to 6.4 VDCat
the power supply. This voltage
can be measured from the pink
wire of the program page connec-
tor to ground.
Our engineers de-
signed the power
supply this way to
compensate for
voltage
losses
caused by natural
contact resistance
in the connectors
and cables. The
cables and connec-
tors will cause a
voltage drop of
about 0.5 volts
even if all connec-
tions are clean and
tight. Additionally, a silicon di-
ode on the computer board drops
the supply by another 0. 7 volts.
Some computers will reboot at
4.85 volts, others may not reboot
until the voltage falls to 4. 75.
Fig 5. 5.7V Regulator and program Plug
CORRECTION
On page 20 of October's STAR
TECH journa~ Bill Cassady of
Bullseye Amusement in Spo-
kane, Washington sent in a tip
about a lamp used in Rock-Ola's
6000X Legend jukebox. Your
suggestion to use a 1251 in place
of the W305 is a good one .
Thanks for the info Bill.
The part number for the original
equipment lamp was supplied
incorrectly and was reported as
being unavailable. The correct
part number is 58201, is in stock
and is still available as a replace-
ment part. Order through your
local dealer or distributor.