Electronics Forum / Repair

Having owned many of these, i often wondered on how to get
the most lifetime out of the battery's.
I have had little used 14.4 volt drills that after 2 or 3
years the battery packs become very degraded. I this case,

So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas.  As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor.  Yet there are controls for
throttle, right and left rotate, and right and left directionality.  

I just found an old discarded Sansui receiver. It works well in all
respects except a large middle section of the AM and FM band don't
receive any stations. A couple of stations on the extreme ends of each
band come in loud and clear, distortion free.

I have two 'old' IP ('network') cameras, neither of which seems to be
able to 'take and hold' a reset to factory defaults. I followed the
procedure outlined in their owners manual. interestingly, both cameras
(an axis 2100, and an axis 2120) have an on-board battery (CR2032 3

Hi. I have a UPS that is not functioning correctly. It's an APC
"Professional Powercell" 250 watt
unit that is at least 5 years old.
When there is a power outage, it beeps loudly but there is no current

I have a Yamaha RX-596 stereo receiver, which has small ?servo motors
that enable remote control of both the volume control and the source
input (phono, cd, tape, etc) selector switch knob. The ?servo motor or
its

Came across this circuit to be used as a dual coil ignition coil driver
recently and tried building it.  However, despite all efforts, I can't get
it to work:
 http://www.capturedlightning.org/hot-streamer/temp/Old2001Files/2001-12/QuadracD
river.pdf

I have a question about ESR measurements.
I have been doing some reading about ESR and the literature indicates
it can be a strong function of frequency.  In the design a SMPS  I
assume the ESR of importance is at  switching frequencies (at least

I notice that some - but not all -electronic ballasts specifically mention
"1 or 2" bulb operation.
Since I have 2 single bulbs fixtures that will need new ballasts and I
happened to have on hand 2 "2 bulb" electronic ballasts of more than

I have a flat ribbon cable in a synthesizer that senses pressure
aftertouch.  It lets you play a note, then push harder on the key to
get an extra effect.  Well, I put a screw through it.  I'd like to
repair it because it's easy to get to the hole, but really hard to