in car entertainment

[Dave]

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.)

[EricP]

You could always use the traditional approach to save time and use a nail!

[R]

It's the current draw you'll need to measure. What (If anything) does any sticker on the unit say for fuse rating?

3a sound a little low for a DVD player. If there's a motor dragging in the DVD and something is stalling it there may be a higher current draw causing the fuse blow. Google the make and see what's recommended

[adrian]

I'm not clued-up on DVD technology either - but replacing a blow fuse with one of a higher rating is a strategy that's a bit on the 'dangerous' side. There's a good chance that the original fuse blew for a reason - and by just giving it more 'welly', you may end up blowing more than the fuse...

Was the player bought 'new'? If so, replace the 3A (blown) fuse - take it back and play dumb 'It stopped working'....

You could put an amp-meter in line and see how much current it's taking

- given that there's probably a fault condition, it's probably pulling more than 3A (to blow the fuse - a lot more than 3A!) - so watch out that you don't blow the amp-meter as well..

Return for refund, or get it repaired....

Adrian

[Mike Dodd]

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).

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.

...

Or send it back for repair, under warranty

Mike

[Andrew Gabriel]

Check carefully for any obvious damage such as crushed cables.

Otherwise, I would guess the car supply is probably fed into a switched mode PSU to derive the stablised supplies the circuitry needs, and this has gone pop.

[Dave]

When I couldn't get any new 3 Amp fuses I tried a 5 Amp. The drive unit sounded like it fizzled for a very short time and when I opened the door for the dvd drive, it was spinning away, but the display was not lit up. It looks like the repair man to me.

Thanks

Dave

[Dave]

A fuse is there to protect the wires. Upping one from 3 to 5 amps should not cause a fault in the system. If it did, then the system already has a fault in the first place.

It's out of warranty :-(

Whenever I measure curent, I always fall back onto my trusty Avo. No internal resistance on Amps. So no problem with blowing it, unlike the modern units.

It's looking like a repair at the moment.

Dave

[Dave]

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.

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.

Out of warranty :-(

Dave

[Dave]

First thing I did, when I replaced the fuse. Check the continuity of the cable from car to other end, everything was fine. I tested it on my 30 amp PSU that runs my amateur radios. I have in line a cigar lighter socket to test car driven devices. It is regulated to 13.8 Volts, the same as you get from a car battery with the engine running.

As I said to another poster, the only thing running is the DVD deck.

Dave

[Andrew Gabriel]

These things are not designed to be repaired. I would price up a replacement system first, and consider carefully what proportion of that you're happy to spend on repairing the old system before committing to doing so.

[Dave]

Thanks, I'll pass that information on to the daughter when I se her Sunday night.

Dave