Will not turn on with good battery.

i kindly recommend you reset teh camera ,also check battery contacts inside the camera and on the battery itself are clean and free from dirt or corrosion.In addition,you can alos buy a new battery

Well the first thing I would do is recommend you send your unit in for service as you may end up doing more harm then good. You can call and get free estimates on what this may cost. If you need any further assistance or help locating a service center let me know.
Thanks,
lee

Full users manual available at:
http://www.canon.ca/inetCA/serviceDetail?m=load&id=2&sid=24&mid=2200842&type=S
or
http://www.manualowl.com/m/Canon/FS400/Manual/122084?page=9
(see page 19+ for charging instructions).

If your Sony camcorder displays a tape transport or mechanical error code always try resetting the camcorder. This is done by removing the battery or ac power, wait 10 seconds, reapply the battery or ac power and try again. If it still goes into error try another tape. The camcorder will not always display an exact error code. Sometimes you may see an error message such as, "Reinsert the cassette", on the LCD screen. This is the camcorders way of saying, "Take the tape out and try again." Try reloading the same tape as well as a new tape. If the camcorder is still going into error this means it is time to send it in for service or repair.
The camcorder may also sometimes display a "Reattach Power Source." This is the camcorders way of saying,"Try resetting my system,so I can try again." Many people mistaken this error and think they have a problem with the battery or ac adapter. This is not true and has nothing to do with your battery or ac adapter. Reset the camcorder by removing the battery or ac power, wait 10 second, reapply the battery or ac power. If the error reappears the unit needs to be serviced or repaired.

Only use the separate adapter. DO NOT PLUG IT INTO AC DIRECTLY!

Follow this procedure to troubleshoot if the camcorder will not turn on.

IMPORTANT: If model-specific information is required to complete any of the steps in this solution, refer to the operating instructions supplied with the product. Manuals are available online in the Manuals/Specs/Warranty section of the Sony eSupport Web site.

1. Remove the battery from the camcorder.
2. Connect the AC power adapter to the camcorder.
3. Plug the AC power adapter into a working electrical outlet.
4. Attempt to turn on the camcorder.
5. Reset the camcorder back to factory settings.
NOTES:

• If the camcorder does not operate using the AC adapter, service may be required .
• If the camcorder does operate using the AC adapter, proceed with the steps below to troubleshoot the battery.


6. Ensure the battery has been fully charged.
7. Ensure the battery is properly inserted into the camcorder.
8. Remove the AC power adapter from the camcorder.
9. Attempt to turn on the camcorder.
NOTES:

• If the camcorder does not turn on, then the battery may need to be replaced.

Follow this procedure to troubleshoot if the camcorder turns off by itself.

1. Remove the battery from the camcorder.
2. Connect the AC power adapter to the camcorder.
3. Plug the AC power adapter into a working electrical outlet.
4. Attempt to turn on the camcorder.
5. Reset the camcorder back to factory settings.
NOTES:

• If the camcorder does not operate using the AC adapter, service may be required .
• If the camcorder does operate using the AC adapter, proceed with the steps below to troubleshoot the battery.


6. Ensure the battery has been fully charged.
7. Ensure the battery is properly inserted into the camcorder.
8. Remove the AC power adapter from the camcorder.
9. Attempt to turn on the camcorder.
NOTES:

• If the camcorder does not turn on, then the battery may need to be replaced.
• If the problem persists using a different battery, service may be required .

Camcorder has charging circuit but it could go defective. The repair would be costly so in this situation, you can purchase stand-along battery charger for around $20 and charge the batteries independently. Make sure all the contacts are cleaned and camcorder is working with direct ac adapter. Good luck -James. for furnter assistance by email, go to www.camerarepairjapan.com

maybe you have a p[roblem with your plug, if you see the orange light then it is charging

Check the output from the AC Adapter first. If no good, battery not charging/dead so nothing works. If good, camera needs service - could be anything. There is probably at least one surface mount fuse.