Mike Dodd wrote:
Dave wrote:
Daughter bought her daughters an in car dvd player with 2 screens and
it has decided to break down.
On looking at the cigar plug end of the power cable, I found a blown
fuse, so I changed the 3 Amp for a 2.5 which is all I have in stock at
the moment and it has blow 2 of them so far.
I measured the resistance of the DVD play power input and it measuered
400 Ohms one way and 800 Ohms when I reversed the multimeter leads.
I'm thinking of buying some 5 amp fuses a.m. and see what it does to
them.
I could conect it up to a variable power supply and see what it is
drawing through, but I thought that this was an unusual thing to happen.
Any ideas anyone? Or does it have to go for repair?
Dave (a bit out of touch with this DVD technology.)
Does it actually work for a bit before blowing the 2.5? (i.e. it's not
just buggered?) If so, check the 3A - is it / should it be an
anti-surge?, have you replaced with fast-blows? (it'd explain it eating
fuses).
Not sure if the DVD spun up up at power on, I didn't hear any sound of a
motor.
As to the fuse I replaced, it was a fast blow and daughter knew nothing
about a fuse in the cigar plug, so I doubt she had changed it.
When you're buying the fuses, get the proper one (3A A/S, or whatever) -
the 5A isn't helping much, except to protect the fuse 
Try a 5A to experiment, if it appears to resolve the issue, look to see
why the unit is still working, but drawing more than the designed power,
it could be as simple as an electrolytic cap failing on the incoming PSU
(I'm guessing the main body will regulate the car supply for the player,
and the two display heads). Look for pressure bulges on the larger caps,
or signs of electrolyte leaking. Have a good sniff - a badly failing cap
(that's taken a bit of current through it to blow a fuse) can, on a good
day, be pretty obvious. And cheap to replace.
Though I have been an electronics hobbyist for a long time, I took out
and replaced with same style of fuse, like for like. When I had blown 2
fuses I decided that I would put a 5 Amp fuse in. The DVD deck spun up
but the displays didn't do a thing. And there is an electrical burned
smell about it.
I am reluctant to open up the case and take a look. Apart from which, I
don't have the time with having the g daughters with us for the week.
Or send it back for repair, under warranty
Out of warranty :-(
Dave