Batboard

I got my kvl a couple days ago.... charged the battery, turned on the kvl...

busy.....
lo charge.....
turns off.


I got a new mx300 battery, charged it 18 hours in the standard charger, then confirmed charge on an analyzer.... kvl...


busy.....
lo charge.....

I dont know how to fix this, any ideas? contacts are clean.

I would say that it sounds like the battery is bad, however you say you checked it on the anayzer.

I forget off hand the exact voltage the KVL's internal voltage detection circuit turn the power off.

I test 3011 KVL's using a rechargable 9V battery (8.4V rated), and make super sure I got the polarity correct before touching the KVL's battery contact. The 9V has enough power to power the KVL for 10 minutes or so.

If your battery is confirmed good, than the voltage detection cut-off circuit is bad in the KVL. If the circuit is bad, you could by-pass it, but don't recommend it in case the battery does go low when loading a key.

Try this with NO radio hooked up:
Power the KVL on and immediately press a number key (try 0 or 1), and press the PTT. Keep pressing the PTT and see if the KVL stays alive. It'll error each PTT, but thats normal if no radio is hooked up. We are just testing if the KVL voltage dection circuit is bad............... Report back

Is this a BX,CX or DX KVL, and has it been upgraded to it's current status?

Maybe the voltage is good, but the milliamp rating has fallen off the charts?

I got sick of buying "new / old-stock" MX batteries that would fail a few months later, so I cut one open and made it into a 9 volt holder. It's great, because if I ever get the dreaded "Lo Cgarge", all I have to do is replace the 9 volt battery. Also, I was able to get rid of that MX charger - thank God.

You can't even tell that it has anything other than an MX battery until you get right up on it. Up close, it's not that pretty, but who needs pretty for a work-bench piece of equipment? I use 4 screws to hold the bottom on, so when if the battery gets low, I just unscrew those. I'll snap some pictures later if you want.

Clean the contacts on the KVL
Tighten the screws on the the base for the battery contacts.
Tighten the rest of the screws on the the base as they all matter in the older KVL.

And of course clean up the MX300 Batt

All contacts 100% clean,

All screw s 100% tight,

The battery is 7.5v 1.4amps,, 1400mah when analyed, which is enough for the kvl.

When powered on, no matter what,

busy...
lo charge...
off... then wont come back on unless battery removed for 1-2 mins.

if I try to power it back on, i get the low bird chirp noise but nothing else.

Hi,

Have you checked/cleaned the fuse? (under the round cap where the battery clamps on)

73 DE Hartley

Yes, fuse is good.

Hi,

I took a look at my 3011CX book (I would assume they are all similar in this area) and it looks like the unreg 7.5V comes from the battery connector (the fuse is in line with the negative contact to ground) thru the flex to the internal board. The unregulated voltage is measured with an op-amp that compares it to the internal 5V regulated and hits the CPU with an interrupt if it isn't up to snuff.

So you have several possibilities:

1. The flex - always a suspect, as is the plug-in connection.
2. The comparator IC or associated components.
3. The CPU/firmware is confused (seems unlikely)

If you can get it open, I would suggest measuring the voltage (with a scope, so you can see transients) on the board itself when you try to turn it on. That should show whether it is a resistive connection or a sensing problem.. my bet is on some sort of resistive connection or flex line.

73 DE Hartley

I checked and the power pull when powered on is substantial! my 2800mAh hicap wouldnt even keep it on. I think there has to be an internal short.

The seller is going to exchange it, but its going to take a week or so to get the new one, thats why I was hoping someone might know how to fix it sooner.

I as of right now (have not been answered), do not have permission to open it from the seller, but hopefully will before sending it back. It may be something really simple inside, I dont and wont be able to check all flex's / circuts unless the seller says I can before sending it back to them.

Nope. wont be opening it, will be returning it.

Thanks all.

Hi - my bet is a failed electrolytic cap.. it's old enuff!

GL!

73 DE Hartley