Battery replacement aaa - Play Inc Bob the Builder Friction-Powered Roley Vehicle

I can't see how a battery vent cap could take out your AC compressor.

http://www.lifegear.com.tw/PDF/16063-Motorized%20Oxy%20Cycle%20Manual.pdf TO REPLACE THE DISPLAY BATTERY:
When the display screen begins to fade, replace a 1.5V "AAA" size battery.
Disengage the digital display computer from top of the device by gently pulling
on it; replace a 1.5V "AAA" size battery.

Did you change the AAA batteries and the internal back up battery? It may sound unnecessary, but sometimes these devices are a little picky. I would also check that the contrast and brightness setting is appropriate. I fixed my dad's just by hitting second and up on the arrow to make the font show up again.

If neither of those work, try these:
(These will reset the calculator and erase the memory)

Remove one of the AAA batteries, hold down on the DEL key while reinserting the AAA battery. The handheld might display "Waiting...Please install calculator software now". If you get this message, the information in the "Correcting the Error Waiting" section shown below will help you correct the problem. Before trying that procedure, reinstall one of the AAA batteries again. This time do not hold down the DEL key.

Remove one of the AAA batteries, press and hold the [on] key for 10 seconds, release, replace the battery, then turn the unit on. Adjust the contrast.

Remove the AAA batteries for three hours. After the three hour period, reinsert the batteries and turn the handheld on. Adjust the contrast if necessary.

First try removing all four AAA batteries and the small lithium backup battery (above the four AAA batteries). Leave all batteries out for five minutes, then replace them and try to start the calculator. If this doesn't work...

Replace all but 1 AAA battery. Press and hold the "CLEAR" button on the calculator. While holding the "CLEAR" button down, replace the missing AAA battery. While still holding the "CLEAR" button, turn the calculator on. The display should read "RAM Cleared". Release the "CLEAR" button and press again to remove the message.

If that doesn't work, remove 1 AAA battery again. Repeat the preceding instructions with the "DEL" key: With the battery removed, press and hold the "DEL" key. With the "DEL" key held down, replace the battery and turn the calculator on. The screen should say "Waiting... Please install calculator software now." Release the "DEL" key. Download this program onto your computer (from Texas Instruments). Connect the calculator to the computer using the USB cable provided with purchase. Run the TI OSDownloader program and follow the on-screen instructions to re-install the calculator's operating system.

To replace AAA battery in hand held yahtzee game, insert a nickle in the slot (near the top) at the back of the game and slide top section forward.

Wilson - The phone was not made to use regular (AAA) batteries. Unless you install AAA NIMH rechargeables it will not work. Regular AAA batteries cannot be charged by the base unit.
In case you meant AAA NIMH batteries as "ordinary batteries" then your charger may be the problem, but I wouldn't assume that until I've taken a pencil eraser and vigorously cleaned the base contacts and tried the base again (with the right batteries.)
Good Luck, Mikeywaf

Not absolutely. The calculator is normally powered by the four AAA batteries. However, if the AAAs drain, then you'll lose all the contents of RAM memory. The lithium battery will preserve the memory long enough for you to replace the AAAs. So, if you don't care about what you have stored in the RAM, you can use the calculator without the lithium battery.

The calculator can work with just the AAA batteries. But, without the backup battery, you'll lose all the contents of memory when the AAAs die. The backup battery is intended to keep the contents refreshed while you replace the AAAs.

Grip the sides of the mouse with both hands and slide the battery cover
back with both thumbs. Then, replace the old batteries with two AAA batteries. Replace the battery cover. Hope that helps.

Try the following

1) Remove one of the AAA batteries, hold down on the DEL key while reinserting the AAA battery. The handheld might display Waiting…Please install calculator software now. Ignore this message. Remove and reinstall one of the AAA batteries again This time, do not hold down the DEL key.
2) Remove one of the AAA batteries, press and hold the [on] key for 10 seconds, release, replace the battery, then turn the unit on. Adjust the contrast.
3) Remove the AAA batteries for three hours. After the three-hour period, reinsert the batteries and turn the handheld on. Adjust the contrast if necessary.

If needed, reinstall OS by downloading the OS from the TI site and ....
On your computer, choose Start, Programs, TI Tools, TI Connect, TI OS Downloader.

(I am not the one who came up with this answer, but found it on an other site. If this doesn't work, please let me know)

Gr Marijn