Updating the canon 30d dslr online
A few drops of isopropyl alcohol (inexpensive and widely available 70% "rubbing" alcohol is fine) on a clean cloth will remove any oils, which are the most likely thing to cause problems with batteries.
An alternative is to use disposable computer keyboard/monitor wipes, most of which are pre-moistened with isopropyl alcohol (check the label).
There's simpy no guarantee this will fix any specific problem. The latter is often a CR2016 or CR2020 lithium or similar in a little tray alongside the main, rechargeable. Among other things, this "date/time" battery serves to maintain the clock and date in the camera while the camera is turned off (your computer has similar on the motherboard).
It lasts a long time, up to five years typically, but does occasionally need to be replaced.
some early BG-E2 grips for 20D were simply were poorly fitted and lose contact, search for DIY fixes on the Internet). Just as a computer sometimes needs to be rebooted to clear memory and remove stray strings of data, doing the same . Remove all the batteries, both the rechargeable(s) and the little silver memory battery.
Let it sit for a long period of time, allowing any and all remaining power in the circuitry to gradually drain off.
Some have had success letting the camera sit for just half an hour, 45 minutes or an hour. If your camera is 4 or 5 years old, you might want to replace the small, silver memory battery with a new one at this time.
If you use an EOS 30D, then you have two ways to update your firmware.
You can use the procedure described, or you can connect the camera to the computer with a USB cable and then use EOS Utility to update the firmware.
Interrupting that installation or installing an incomplete FIR file can "brick" a camera and require it be sent in for repair.