dvd player circuit board..

[CTURNER86]

my freinds dvd player broke and asked me to have a look, after opening the case i see the inside fuse had blown where the power cord comes in but also on that circuit board another small square shaped chip has blown above it on the circuit boards says IC3 i need to know , where i can find another one or is it waste of time trying to fix it?? its a Digilogic dvd 4400

all feedback most appericiated

 

[ericmark]

It is near impossible to work out what a chip does unless one has the plans. Even when it has the part number printed on it with PIC's they can have many different programs burn into them.

Switch mode power supplies are really a problem as unlike with old power supply where one could get a meter and slowly work out from power in because there is a loop that method can no longer be used.

So repair today is done by changing a module and this means the repairer needs to have spare modules to drop in to find which one has failed.

So the guy who would repair any TV has gone. They have to limit themselves to a range of which they have the spares. And with a whole DVD player costing around the minimum charge to do simplest of repairs they have become disposable items.

 

[CTURNER86]

im guessing schematics diagrams are not easy to come by then ive had a good look on net but not luck so far,.. i shall advise him to buy another one but if anyone knows where i could get a schematics diagram i still would like to have a go at fixing it , if only for my own experiance

 

[tomathy]

Does the burnt out "chip" look a bit like this?

Given that you say it's physically close to the power inlet, it's likely to be a voltage regulator. If you can read the markings on it then you should be able to order a replacement or equivalent. This isn't to say that this is the only fault - the regulator may have blown as a result of another component failing.

It is near impossible to work out what a chip does unless one has the plans. Even when it has the part number printed on it with PIC's they can have many different programs burn into them.

I'm not quite sure what it is that leads you to assume that the "chip" in question would be something as specific (and unlikely in this sort of kit) as a PIC. While you may be correct in assuming that certain components within the DVD player may be loaded with firmware, I'd expect them to be surface mount and have large pin counts, both of which make replacement "in the field" near impossible anyway.

Tom

 

[CTURNER86]

IC3

• CTURNER86
• 3 Feb 2011
• 1

looks more like this.... and most of the top cas burnt of so cant read anythink, all i know is what it says next to it on the circuit board

 

[tomathy]

Can you read the markings on the chip itself? IC3 is just the designation the designer of the circuit has given to the chip within the circuit itself, and doesn't actually tell you what it is or what it does.

 

[CTURNER86]

no

 

[Stivino]

I believe the Digilogic dvd 4400 was originally £25 in Tesco so it's probably not worth the bother as a new budget DVD player is only about £20 now.

 

[gblades]

The only real ic thats used in a power supply is the switch mode controller which controls the pulsing of the transformer output through a transistor to maintain the correct output voltage.

In most cases it is the final capacitor which fails and that can put extra strain on the transistor causing it to produce more heat than the circuit is designed for and can cause that to fail causing a short circuit which blows a fuse or an over voltage which can damage other components.
If you just replaced that component it is very likely that the replacement will fail. If you wanted to replace it you would need to test the rest of the system with a different powersupply to make sure it is on and then inspect and replace all the capacitors, switching transistors and the failed ic.
For what you paid for the DVD player its really not worth it.