Yamaha DVD S520, dead, wont turn on. Power supply PCB 3 2260 138 056649 has a burnt smell in the centre of the board in the area of a three pronged componet

Hi Keith,
First try to replace your power cable if it seperate from your TV and use another power socket to cofirm your cable is good and power socket. If your power cable is attached to the TV then just take the set to repaire centre and get it fixed.



Regards
Ashwin

No one turned off your power switch up above the refrigerator, I trust. So, either your power supply or your main PCB is blown. Check the fuse on the main PCB (up on top of your refrigerator in the compressor area). The fuse will be right next to that round, black piezo electric speaker on the main PCB board as shown here:



If that's not it, then check to see if your power supply board is supplying power by measuring the voltage on JP11 of the Main PCB. You should see 26 vdc between pin 3 (GND) and pin 1. And, you should see 12 vdc between pin 3 (GND) and pin 2.

If you don't get those voltages, then you might have a bad Power Supply Board. It looks like this:


Also of note, your 120vac going into the Main PCB board comes in on JP8, pin 1 (WHT) and pin 5 (RED).

I don't know if you will be able to see the larger image of the schematic, or if Fixya will just give you a thumbnail, but I'll try to post it here, anyway:



Well, good luck and let me know if you need any more assistance.

Typically if one inspects the boards in question you may find evidence of heating and damage. Sometimes with newer solder having no lead, hot spots tend to leave cracks around the joints of parts heating and cooling and once they arc they fry components. One can usually smell a burnt component altho hard to describe the smell. I would look for burnt fuses on the power board where the power first enters the back of the tv, and some fuses are covered with a plastic sheath and looks like another type of component. A tester comes in handy... I suggest that you look more at the board that gives the high voltage to the TV screen, as there are step up transformers (square blocks) that give a lot of trouble and the transistors surrounding those blocks, usually 4 transformers. I would test for continuity around these areas but the transformers should be pulled from the board for a more accurate test. Inspect transistors (black with three prongs) usually has an aluminum heat - sink attached to it for cooling, anything more than 3 prongs is probably an IC or integrated circuit chip. These are more difficult to test. A diode will allow power one way but not the other so reversing the polarity tester tips will give you a voltage or nothing in reverse. Transistors are similar to a diode in that you can test it one way but it shouldn't be a reading the other to try to keep things simple. Typically when a transistor goes it will burn a hole in the face or on top. A capacitor looks like a mini soup can and swelling on top a hole on top or liquid stain under it is an indicator that it's bad. Typically the top is swelled and the plastic coating bares most of the top of the capacitor. If one inspects other capacitors in that area you can notice the difference even though indicators are slight at times. I would at very worse put the screen part away until you found a suitable tv model with a broken screen perhaps on kijiji. Typically it is a capacitor that has blown but may only lead to a partial solution to the problem if several parts are gone which is usually the case, a capacitor or two as well as a transformer or a transistor; and one must also inspect and test other components in that same area for success and to inspect the circuits for cracking around components especially where the hot areas are and one can usually see these hot areas due to the discoloration of the board in these areas. These hot areas are usually the problem. One overall solution is to build a big fan into these tv's lol and put surge protector bars on all your expensive electronic components.

This oven is programmed with a self diagnostic failure code system which help for troubleshooting -H97 and as described above "mica piece and burnt smell" sound like Inverter Power Supply. DO NOT try to repair or re-adjust preset volume on the board. It is very dangerous to repair or adjust without sufficient test equipment because this circuit handles very high voltage and very high current Operating a misaligned inverter circuit is dangerous due to the Very HIGH voltage and current that is produced by this board.

Defective board must be replaced with new one -INVERTER POWER SUPPLY.

Make sure your RAM and all your cards are seated correctly. I'm guessing based on the static sound and immediate loss of power that your power supply is damaged and needs to be replaced. If the fan in your power supply doesn't turn on, this is in indication that you have a dead power supply. Smell the power supply to make sure it isn't burnt. It will be very obvious if it is.

If there are no lights at all coming on, its ,more than likely the power supply pcb that needs to be replaced. I hope this helps

Try these for starters!
Is the power switch broke? Check the power cord! Are any internal fuses blown. Look inside for damage/burnt parts. Are the printed boards broken? after say being dropped? Is the transformer working? Check around the power supply area for faults.
Note - be careful your dealing with mains electric!

even if the power button is deffective, you can have it turned on using the remote contro. if still doesn't work then you have a problem with the power supply unit. you need to have it chekced by a service personnel

yes sir, starting to malfunction and needs replacement now. unless you cant ry cleaning it manually maybe it will help a little but sooner or later it will again give you same trouble

Do you have a LAN connection on the machine that you use? That would be an area to start to make sure that (when a LAN cable is plugged in, the incoming and outgoing lights will blink) the power supply still works. If the power supply does still work, it could be the motherboard or CPU which isn't working. It could be something simple like thermal compound needs to be reaplied to the CPU, or there may be faulty hardware. Let me know if the power supply is still working.