I have an update on the internal sled/NiMH AA issue.
I've had a re-occuring issue with the batteries in the sled discharging over time in the recorder.
Originally, I thought just putting the AA cells in the sled and putting the sled in the 671, that over time the recorder would discharge the batteries. Even if it was turned off. We'll, I put some Duracell 2500 mHa NiMH in the sled and left them for a week. No problems, they were fine after a week. Then I plugged in the external AA battery pack I made (with no batteries in it) and left the sled in and after 30 hours, the internal sled batteries were fully depleted! I checked the external pack for a short, and it is operating fine.
After seeing the results of this test, I would recommend not plugging in an external pack until you are ready to use it.
Looking back, I believe this is what has been my problem all along, having batteries in the sled and having an external battery pack pluged in at the same time. BTW, if there are batteries in the external sled, they get depleted as well.
When I have the time, I'm going to test the external jack to see what is going on with it...
To me, this is good news, as I was thinking that there was a problem with the 671, that it would deplete batteries, in the sled, without even being turned on!