[Yaesu] FT-1000 Tuning Upgrade Kit Instructions from International Radio Services

[Paul Christensen]

Been traveling much during June, but as promised, here are my findings 
concerning the FT-1000D memory loss issue.  First, the RAM chip was replaced 
on the Control Board.  No luck.  The RAM chip is the terminating point for 
the battery back-up.  As noted earlier, battery voltage measured fine all 
the way to the RAM power pin.

Next, I replaced the EEPROM chip.  Several on-line vendors sell V6.0 ROMs. 
After replacement, the FT-1000D functions as new.  Possibly the EEPROM had 
become corrupt over the years as in the case where long-term exposure to low 
light level can still affect programming.  So, problem solved and the owner 
of the FT-1000D is very happy.

BTW, I jettisoned the International Radio tuning upgrade board and rewired 
the FT-1000D back to stock condition.  I did this to aid in troubleshooting 
with the thought that if the root cause of the problem was found, I would 
re-install it.  However, I did not detect any real value in the device and 
so the FT-1000D remains as a stock transceiver.

Paul, W9AC

-----Original Message----- 
From: Paul Christensen
Sent: Monday, June 01, 2015 1:43 PM
To: yaesu at contesting.com
Subject: FT-1000 Tuning Upgrade Kit Instructions from International Radio 
Services

Thanks to all who came to my rescue with offers to help.  John, GW4SKA just
sent me the .PDF scans.  With that, hopefully I can make some good progress.

The oddity to the FT-1000D's memory loss is that the back-up battery voltage
appears all the way to the one and only connection point and that's the
28-pin RAM chip.  Through a steering diode, that point is in parallel with a
+5V source from the power supply for memory operation while the rig is
running.  So, all normal there.

All I can figure is that the back-up core
of the RAM isn’t loading.  The Yaesu service manual is of zero help; there's
no description of the load/recall.  However, while the rig is powered on and
making panel changes, it
does retain frequency, band, memories, etc.  But all is lost at power-up and
reverts to 7.000 MHz on both VFOs.

I'll post results when I find the root cause.

Paul, W9AC