PIEXX ICOMPROM IC-751 / IC-751A RAM / PROM Memory Board
If you have a Icom IC-751 or IC-751A transceiver you probably know that when the internal battery gets weak the transceiver stops working! PIEXX has corrected this problem with the new ICOMPROM Ram replacement board. The ICOMPROM board is a new, plug compatible, memory module that keeps the important setup information in an onboard non-volatile PROM device while employing a battery backed RAM for saving the memory channel data. With the PIEXX ICOMPROM board you will never need to worry about your transceiver going dead from a low battery again!
Installation in IC-751 / IC-751A
1. Record any important memory information that you want to retain from your old memory module. Since you are replacing the transceivers RAM, this information will be lost when the new board is installed. 2. Disconnect the power cord from your transceiver!! 3. Remove the bottom cover of the transceiver. 4. Locate the old Icom RAM board, it is ~ 2 inch square board with the coin cell mounted on it. 5. The old ram board is held in place with a small Phillips screw in one corner of the board. Remove this screw and unplug the old RAM board. 6. Carefully align the new board with the connection pins protruding from the Icom logic board. There are 2 connectors which need to line up, a 12 pin and an 8 pin. Be careful to be certain that all of the pins are aligned with the mating receptacle on the PIEXX ICOMPROM board and then press the board down onto the pins.
Figure 1. PIEXX ICOMPROM board Installed in the IC-751 Xcvr
7. Replace the bottom cover on the radio.
Checkout in IC-751/IC-751A
When you first power on the transceiver, the display may read an unusual frequency like 666.667.8. This is normal after the initial powering up of the system. You must initialize the RAM settings as follows: 1. Set the HAM / GEN purpose function to the HAM mode as indicated by the red GENE message in the bottom left corner of the display being EXTINGUISHED. That is, you shouldnt see the GENE message. 2. Select a band by pressing the Band button and rotating the tuning knob. 3. Select a mode, USB, AM, LSB, your choice. 4. Set the VFO B info to that of VFO A by pressing the A=B button. 5. Preset the 32 memory channels in the normal fashion. If you havent set a particular memory channels data, but try to recall it, the display may show an improper frequency or mode.

Installation in R-71A

1. Record any important memory information that you want to retain from your old memory module. Since you are replacing the transceivers RAM, this information will be lost when the new board is installed. 2. Disconnect the power cord from your receiver!! 3. Remove the bottom cover of the receiver. 4. Remove the mounting plate covering the Logic board, there are four screws securing it. 5. Locate the old Icom RAM board, it is ~ 2 inch square board with the coin cell mounted on it. 6. The old ram board is held in place with a small Phillips screw in one corner of the board. Remove this screw and unplug the old RAM board. 7. You can increase the clearance between the ICOMPROM board and the mounting plate, removed in step 3, by trimming the logic boards RAM connector pins (the 8 and the 12 pin connectors) by about 1/8. This modification isnt 100% necessary, but it is a good idea. 8. Carefully align the new board with the connection pins protruding from the Icom logic board. There are 2 connectors which need to line up, a 12 pin and an 8 pin. Be careful to be certain that all of the pins are aligned with the mating receptacle on the PIEXX ICOMPROM board and then press the board down onto the pins. 9. The Logic board cover plate has an insulating material glued to its bottom. Make sure that the insulating material is in good condition, and replace it if not. This insulation prevents the battery on the IcomPROM board from shorting to the cover plate. 10. Replace the Logic board cover plate and the bottom cover on the radio.

Checkout in R71A

1. When you first power on the receiver, the display may read an unusual frequency like 666.667.8. This is normal after the initial powering up of the system. You must initialize the RAM settings as follows:

2. 3. 4. 5. 6.

Enter a valid frequency with the numeric pad and press the ENT key. Select a mode, USB, AM, LSB, your choice. Set the VFO B info to that of VFO A by pressing the A=B button. Save this frequency data to memory by pressing the WRITE key. Preset the 32 memory channels in the normal fashion. If you havent set a
particular memory channels data, but try to recall it, the display may show an improper frequency or mode.
Figure 2. PIEXX ICOMPROM board Installed in the R71A Receiver

Jumpers

Unless otherwise noted, the ICOMPROM board is shipped with the jumpers set for the IC-751 / IC-751A transceiver. JP1 OUT IN OUT IN OUT IN JP2 OUT OUT IN IN OUT OUT JP3 OUT OUT OUT OUT IN IN JP4 OUT OUT OUT OUT OUT OUT Radio R71 IC-745 IC-751/IC-751A IC-271A IC-471A IC-1271A