I have 7690-2 ROBOTOOLZ that wont run on batteries. Is there a fuse somewhere? Works with AC adapter but not handy on job sites

SHARCNET-USA

• 2130 Answers
• Posted on Jan 24, 2008

SOURCE: Milwaukee Job site radio

Questions:
1. Does the AC cord look ok? Not damaged?
2. Have you tried another AC outlet?
3. Does the AC cord unplug from the radio?

When you operate the radio from the AC power cord, the radio uses an internal power supply consisting of a step-down transformer, rectifier, and filter that converts the AC to DC to operate the radio.

When you run the radio off of batteries, it powers the radio directly. In some radios, when you plug the AC cord into the radio, it activates a switch that disconnects the battery voltage to the radio so that the batteries wont be damaged from the voltage created by the internal supply.

The radio can be powered by either the batteries or the internal supply. You don't want either supply affecting the other, so that is why a switch is sometimes used.

Since the radio works fine off of batteries, that would indicate that there is a problem with the internal power supply. This could be a blown fuse, bad transformer or bad rectifier diode.

Good Luck,
- Jim

SOURCE: Battery compartment disconected by the AC adapter

That could be any number of things. Broken solder joint on the board where the battery terminals connect, dead batteries, and now that I think about it, if the connection is broken or loose in any way inside the hole where the ac adapter goes, it's not going to work with batteries. It needs that completed circuit regardless if there isn't an ac adapter inserted.

SOURCE: ibm thinkpad no power with ac power adapter but works with battery

If prior to this it works intermittently with the AC adapter, it means the connection from the adapter power unit to the motherboard was lost and this is a typical problem with the Thinkpad. It needs a re-soldering job and not something that one can do without a proper repair manual on how to open the laptop. Try googling your problem and find out if someone has the same experience and managed to resolder by him/herself.

SOURCE: ac adapter's wont charge battery or pwr. unit

I would say take to a good PC repair shop (Not Geek Squad) and ask them to look at the power jack on the motherboard, it may need replacing. Next would be more of a a motherboard problem and its just quit. Good repair shops could help you either way get it fixed. I don't recommend anyone tackling any sort of laptop motherboard fix unless you really know what your doing.

SOURCE: i had the battery not recognized on boot up. then

the Dell AC adapter has a sensing pin so the bios can determine the wattage of the adapter. If the system cannot ID the adapter, the battery charger circuit is disabled. You'll need a functional DELL ac adapter to get the battery to charge

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