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ICOM R-7000 Display/Sensitivity Problem [message #76] Sat, 09 September 2006 22:01 Go to next message
root is currently offline  root
Messages: 207
Registered: December 2004
Senior Member
If you are having trouble with you Icom R7000 display being flaky and then a sudden decrease in sensitivity try the following:

PROBLEM: ICOM R7000 radios that are used 24 hours a day for a long time (2 years ) when shut off the display will become flaky and it is also possible for a lost in overall gain (3 to 40 db).

SOLUTIONS: Officially there is ICOM ECO SB# 9288-004, attached below.

Unofficially from Tech who repairs R7000, the ECO does help the display problem, but most likely it is not the problem. *

* note repairing your own radio my void you warranty and only allow a qualified technician to do the job, otherwise damage could happen to your R7000. If the VCO does not track then a major alignment would have to be done after. Check the ICOM IC-R7000 Service Manual for more details before starting this repair, and to make sure I have not made any typeing errors you should get a copy of the ECO from ICOM !

1st SOLUTION: Replace on the DC to DC Board the following capacitor. Check the noise with an oscilloscope on both sides of R3, if the noise is not way down on one side then replace C2 a 33uf 16V capacitor. Noise feedback can decress the overall sensitivity of the R7000.

Replace on the Display Board C19 and C20 a 10 uf 16VDC capacitor

I found that on my R7000 C19 & C20 were the cause of my display problems. They are 10 uf eletrolytics capacitors that are lemmon yellow pc mounted units, when they go bad the base of the yellow caps change to a brown color.

I put in the following ECO first but it did not help. If you look at the service manual you will see that the ECO values are on the schematic but my unit had the old values. I suggest that you check the above first, it is a lot easier to do, C19/C20 can be done in 10-15 min while the ECO will take about a hour.


2nd SOLUTION: The ECO

ICOM America, INC
2380-116th Ave, N.E.
Bellevue, Washington 98004
206-454-7619


SERVICE BULLETIN

UNIT MODEL R7000
SB# 9288-004
EFFECTIVE DATE 4/1/88
SERIAL # AFFECTED: ALL
PRODUCT GROUP: Amateur


BACKGROUND INFORMATION: Display failure do to weak components

TECHNICAL INFORMATION: Improvement in DC to DC converter and display power supply.

PARTS AFFECTED    BOARD TYPE    CHANGE TO    NEW PART NUMBER
Q1/Q2 2SC 1214    DC to DC Board    2SC 2655    906-00385
R1/R2 3.3 KOHM    DC to DC Board    5.16 K        915-01173
C3/C4 PF    DC to DC Board    0.001 MF 50V    918-01500
                ceramic cap
Q11/Q12        Display Board    2SC2655        906-00385
R31/R32    3.3KOHM    Display     5.16k Ohm    915-01173
C13/C16        Display        0.001 MF    918-01500


DETAIL PROCEDURE:

1. Remove top and bottom cover.
2. Remove front panel sub-assembly from main chassis of radio
3. Remove the DC to DC board and replace components as listed
4. Reinstall DC to DC board.
5. Replace front panel sub-assembly onto main chassis of radio
6. Replace top and bottom covers.


ESTIMATE TIME TO COMPLETE IS 1 hour

Page 2 of the ECO has a new schematic but no information
Re: ICOM R-7000 Display/Sensitivity Problem [message #121 is a reply to message #76] Sun, 11 March 2007 22:35 Go to previous messageGo to next message
celes_maxtrac is currently offline  celes_maxtrac
Messages: 10
Registered: February 2007
Junior Member
Wow! This is a detailed info. It's nice to see this posted.

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[Updated on: Sun, 11 March 2007 22:36]

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Re: ICOM R-7000 Display/Sensitivity Problem [message #1346 is a reply to message #76] Sun, 13 May 2012 23:15 Go to previous message
snowman is currently offline  snowman
Messages: 2
Registered: May 2012
Junior Member
woo,it's useful and informative Very Happy Very Happy Very Happy
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