The PRO-2004 scanner can be used to receive cellular telephone conversations. Originally, the scanner was able to receive in this band, but at the last minute, it was decided to delete cellular coverage from the PRO-2004.
The procedure to re-instate the cellular band is simple for anyone with a pair of cutters, and a phillips screw-driver.

1. Remove the four screws from the back of the radio, and slide off the cover from the chassis.
2. Turn the radio upside down. You will find a metal box-like sub- chassis in the center of the main chassis. Remove the cover and you will be looking at the CPU, a 64-pin integrated circuit.
3. Examine the component side of this board, and you will find a row of diodes and resistors. On one end of the row you will find a diode labeled D-513.
4. Clip the accessible end of D-513, and pry apart the ends so they don't touch. You have just restored cellular coverage to you scanner.
5. If D-513 is not there, it may be located on the underside of the circuit board.

1. On the top of the sub-circuit board, locate the slot for D-513. Count backwards from there until you get to the space for D-510. Install a diode at D-510 in the same polarity as the rest of the diodes. There, you now have 400 channels instead of 300.
2. Now install a diode at D-514 and you have increased the scan speed to 20 channels/sec from 16 ch/sec.

1. remove the top cover by unscrewing the 2 screws in back. (be careful of the speaker cable which is attached to the top part you would be removing).
2. locate diodes D502 & D503 behind the keypad.
3. clip the lower diode (D502) to allow access to the cellular freqs.
4. clip the upper diode (D503) to increase the scan speed to 30 chnl/sec.
5. set up search banks to operate in the 869-894 Mhz range.
6. use the (previously unavailable) 30 Khz step while searching in that range.

After removing the two upper back screws and the top lid, locate the black cable just behind the front panel. Adjacent to the cable is (diode 44) clip one end or remove entirely and the complete celluar band isrestored.

1. To restore missing 800 MHz frequencies, remove D-11.
2. To add 66 to 88 MHz (European Coverage), install a diode at D-9.
3. D-10 must remain in place for full 800 MHz coverage.
4. If a diode is added at D-13 it cuts out aero band, also seems to affect 800 MHz channel spacing.
5. D-12 added dosen't seem to have any affect.
6. Only D-10 and D-11 are factory installed.

PRO 37 CELLULAR RESTORATION

1. Find and remove (D-13).

1. Find and remove (D-6).

TOOLS REQUIRED: Small Phillips screwdriver,small wire cutters.

1. Slide off the battery pack and remove the antenna from the scanner.
2. Using a small Phillips screwdriver, remove the two screws from the back of the scanner, the two screws which hold the battery retaining spring at the base and the spring itself.
3. Carefully pry the bottom of the rear cover from the radio and remove the cover.
4. Locate the two small screws at the base of the circuit board and remove them. Gently pull the front panel from the mainframe at the base and separate them.
5. Locate the (64 pin quad flatpack) microprocessor IC labelled "UNIDEN UC-1147" and the 10k ohm (brown-black-orange) leadless resistor positioned above the letters "DEN" on the IC.
6. Using miniature wire cutters,(cut the resistor body in two without disturbing anything else near it). If the left solder pad comes loose, it may be peeled from the board. Brush or blow away any residue. This completes the restoration.
   
7. REASSEMBLE THE SCANNER, switch the scanner on to make sure the display comes on. If not, the battery is discharged or the dual-inline connector was misaligned during assembly . Assuming the display comes on, press: MANUAL, 845.0, E; within two seconds, the frequency 845.000 should appear on the display.

1. remove all cabinet screws.
2. remove 4 face plate screws and 1 bracket screw at center of main board.
3. carefully depress the outside edges of faceplate shield and tilt down.
4. unplug j4 and j5 and ribbon connectors j501 j502 and j503.
5. remove faceplate and logic board.
6. position board so microprossesor chip is on left and memory battery on right.
7. locate the 3 chip resistors at chips upper right..marked 104 and carefully desolder.
8. install the chip resistor at the 2 empty pads closest to memory battery.
9. reassemble carefully in reverse order.
10. test by entering freq. around 870 mhz.