removed the CFL lamp and converted them to LED back-lighting
The CFL lamp generates a lot of heat and causes the units to fail.
You will need the following.
5 - Surface mount LED's high output white type.
I used these - 5050-PW6000 Pure White 5050 SMD LED $0.65 each from http://superbrightleds.com
1 - 560 ohm 1/2 watt resistor.
Remove the knobs and remove the back of the control head. 4 screws and lift off the back.
remove the 5 screws that secure the PCB to the front. 4 long ones and one short one.
Be careful as the LCD panel is loose at this point. unplug the CFL lamp and very carefully remove it from the slot.
you will have to lift up the plastic sheets and slide it out.
Then build the led strip and very carefully slide it into the slot where the CFL was. making sure the LEDs are facing down.
Re assemble the unit to the face, holding all the parts together, LCD panel and the newly installed LEDs.
screw the PCB back on to the face with the 5 screws.
Locate the coil that powers the inverter, and heat one side until you can lift it from the PCB, be careful as this is very delicate.
Solder the negative lead to the metal shield and the positive lead to the 560 Ohm resistor. The other end of the resistor goes to the coil you lifted up slightly.
If everything went properly it should light up very nicely, even brighter than the old CFL.
PCB removed and ready for modification
Remove the lamp, and be careful with the LCD panel and the plastic sheets behind it.
Connect 5 SMT LEDs make sure the alignment is correct, they have a notch in one corner. Make the strip approx as long as the original CFL lamp, about 1 inch shorter will work fine.
Notice the notches are all facing the same direction :) I cut the excess wire off and soldered short leads to run to the solder points on the PCB. the negative lead I just soldered to the metal shield. Test with a 1k resistor and battery to double check the positive and negative lead.
Very carefully lift the side of the coil (labeled 101) from the PCB, this is the power supply to the inverter, I used that to power the LEDs as I do not want the inverter running. Connect the current dropping resistor to the end of the coil you lifted, mine tipped up very nicely and the resistor soldered to it just fine. If you notice the picture is 2 780 ohm resistors in parallel, I have since replaced them with a 560 ohm 1/2 watt resistor. less current only about 25 ma to the LEDs.
And there you are, it looks great. and actually brighter than the original CFL with no heat.
after running for several hours, the head is now only slightly warm.
Update: per request 2-26-2014
I have successfully completed this modification to 3 of these radios with 100% sucess.
For those interested in the parts that are suspect if your unit will not power up. look at these components
In the 2800 control head (to fix this intermittent turn-on failure) the following parts were replaced:
IC14 (according to Icom this is a component they replace for this issue, however I did not have to)
Q18 (Icom also recommends replacing this transistor, In my case I did not need to)
C128
C38
C125
C126
C149
C155
(for me at least) replacing the capacitors listed should fix the turn on issue, they seem to be leaky and cause the voltage regulators to fail to operate properly.
You can download the IC-2800H service manual here:
http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=ICOM
73's
Cody
