[colinh1301]

Hi there - first thread and first time into electronics

I have a in car two screen DVD player which has stopped working.

It is a Venturer PVS6988.

When the power supply is plugged in the DVD fails to power up additonally the light on the power supply goes out. I have tried the power supply on an other item and it works fine.

From a quick trawl on the internet I believe this would point to a short circuit.

I have opened up the player and there are two circuit boards. A small one with which the power supply, on off switch and the socket used to connect the slave screen and a larger one which is connected to the DVD drive etc.

The small board is connected to the larger one vis a load of small cables which are connected via two plugs.

I have disconnected the plugs to isolate the smaller of the two boards. I connected the power suppl up to this small board and the light on the power supply still goes off straight away.

The machine is a few years old and was working fine until the fault happened.

I tried checking the continuity on bits of the board but I really have no idea what I'm doing.

I'm not sure if its just me but one of the bits I thought was a bit odd is the on off switch. Its a simple slide switch with an on and off position. It has 5 connections on the back and there always seems to be continuity across any combination of connections irresepective of what position the switch is in.

looking at the rest of the board some of the 'lines of solder' seem to be a bit 'worn'.

Any help would be gratefully recieved.

Photos dont seem to be loading but can be viwed here:

https://picasaweb.google.com/colin1301/DVD#

cheers
colin

 

[kwoolsey94]

By the looks of the pictures you supplied , one of your electrical bus's seem to be broken. If you look in the 2nd picture you will see that one of the electrical strips is an ugly brown color. By the looks of it has broken off or a solder has gone bad.

 

[(*steve*)]

That ugly brown colour you refer to is the copper on the board. It's actually more conductive than the solder.

It is odd that it's not coated with solder like the rest of the board. Perhaps there was some contamination when the board was soldered. I might check all the connections near this point. Touch them with a soldering iron and make sure they're all OK.

 

[TBennettcc]

Any way to get the full 12 megapixel images?

What's on the board between the power connector and the small fuse?

 

[colinh1301]

The areas where the solder is missing are still conductive, as best I can work out (I touched either end with my multimeter on the continuity section).

The square silver box next to the power supply is the socket where the slave screen is attached.

I'm a bit suspicious of the switch - it seems a bit 'wobbly' (the switch mechanisim not its connection to the board), I'm thinking its the one moving part the kids get their fingers on (who are not the most light fingered). Is it possible that it could be shorting? How would I test it. Why does it have 5 connections.


Cheers
Colin

 

[(*steve*)]

The 2 outer connections on the switch are probably for mechanical strength. It is likely that the inner three are the ones used for the contacts (not always true, but the end ones look larger, and I bet they're connected to the body of the switch)

The switch may feel wobbly because the actuator may just be a sleeve over the real actuator of the switch. It needs to have some play (possibly) to match up with a plastic cutout. If the switch body itself is wobbly then that is a more serious problem.

You should be able to use a multimeter to test the switch. Determine what connections are switched, then see if the resistance changes when you wobble the switch -- it shouldn't.