TV Remote eating batteries

[swrlyhrly]

I've only recently gotten into electronics and I have basic knowledge on how resistors, caps, diodes, and all that basic stuff works as well as a sort of understanding on logic gates and such.

For about the last year, my TV remote has drained fresh batteries within a week and rechargables in about 2-3 days (they're getting old). I opened up the remote and unsoldered one of the battery leads so that I could put my multimeter between the batteries and the solder point on the pcb. I was pulling .002 amps (2 milliamps right?) constantly and pulling .007 amps when pressing any of the buttons.

Another odd note was that one of the battery terminals was melted slightly into the plastic of the remote. I had to heat up the spring with my soldering iron to release it from the plastic.

Anyone have an idea on what to look for? I'm assuming that when not pushing any buttons i shouldn't be pulling any current at all or at least so little it wont even register. It shouldn't be pulling current I think to keep the tv codes stored because i've never had to reinput codes even when the batteries are out for days.

Thanks in advance for any help

 

[kchriste]

Maybe someone put the batteries in backwards once and hence the melted battery terminal and partially damaged it. A good design should be able to handle that. Maybe yours isn't one of them.

 

[blueroomelectronics]

TV remote controls are a dime a dozen, often better than the original.

 

[Gayan Soyza]

In my TV I replace the alkaline s once a year.

First time I heard such a thing. Is that happened recently? May be your remote sending some hidden pulses continuously.

Better you check the remote with a remote checker whether it is sending pulses even in standby mode.

Also note some remotes are there, they are ready to receive the TV sending pulses. So in this case the remote will draw current.

 

[Nigel Goodwin]

There's usually (always!) an electrolytic across the batteries, these sometimes go leaky, and cause just what you're getting.

 

[swrlyhrly]

The caps were the only thing i could think of. They looked just fine on the outside but i don't know how to test them. Maybe take them out and see if one of the two loses charge really fast?

This is a dish remote by the way and they cost like 40 bucks for a new one. I'll try the capacitor thing and see if that produces any results. If not, then its not really a big deal, I'll just keep recharging the batteries.

 

[mvs sarma]

If by any chance, a key is locked up in pressed position, it drains battery. If the TV has a normal LED also which blinks when ever the remote is used, it could indicate.

alternately, you could take your Remote very close to an AM or Shortwave of a radio on lower frequency like 3Mhz or 5MHz, the remote signals can be heard as clicks of noise in the radio.
Now even without pressing any key, sequences of clicks are heard, you can ascertain that one of the keys got stuck
Perhaps you can open clean the rubber pad and put back it should serve.

 

[blueroomelectronics]

Replacement remotes often cost more than Universial remotes, your local WalMart should have buckets of them for about $10. Just make sure it supports your Dish.

 

[zevon8]

I'd say Nigel has it in one. Backwards inserted batteries baking the electrolytic, it has gone leaky. Swap it out.

 

[spuffock]

I'll go along with Nigel, and blame that capacitor.
If it helps any, you can see the infrared signal in the viewfinder of a digital camera or camcorder.

 

[swrlyhrly]

Thanks for the help guys I'll definantly swap out the capacitors and see if that works. I'm not thinking its a key stuck as i've had the remote apart several times as well as like i said it pulls 2 milliamps constantly and then spikes to 10 and settles at 7 milliamps when i press a button. i would think that the current draw would go up equal to what is being drawn constantly.

I'll let you know if it works.

 

[swrlyhrly]

I forgot about the AM radio thing. I'm definantly going to try that. Does that only work for IR remotes or UHF as well. UHF is like radio signals right? Mine does both IR for the TV and UHF for the dish because I'm on the the second channel of the dish reciever so all i have is a long cable to my room that has an antenna on the end.

I've heard about being able to so IR on like cctv and some other cameras, but i don't have any that I know of that can see IR. I've tried on my laptop's webcam but no go.

Thanks again

 

[RODALCO]

I second, third, quad, Nigels comments regarding the electrolytic. If you can't test it get a new capacitor.

Most remotes are 3 or 6 volts so a 16 or 35 Volts cap should suffice, as long the size is about the same and fits.

There should be zero leakage current when no buttons are depressed.

 

[Manaco]

I had a similar condition with Sat Remote that eradicated by replacing the capacitor ( 10V 47uF ) on the remote Board with an equal one.
For better understanding I gonna include an image too.

 

[cowboybob]

Welcome to ETO, Manaco!

Where were you 11 years ago???

Anyway, thanks for proving the point...