Samsung Syncmaster 940be

SYMPTOM:
No power.


PROBLEM:
Bad caps on the power supply.



SOLUTION:
Replaced 4 1000uF / 25v electrolytic caps on internal SMPS (switch mode power supply)

SAVE AMERICA

One of the most common failures in LCD flat screen displays are electrolytic capacitors. These electronic components are prone to premature failure due to the compact space they are used in here. There are also a few other matters that can be blamed for this very common and very unnecessary problem. There is actually a web site dedicated to the topic bad capacitors (www.badcaps.net), among others.


   While this problem has given birth to businesses such as my own, I'd rather not see the American people getting scammed like this. There is absolutely no accountability to the manufacturers after the 1 year warranty. I warranty the units that I sell for 1 year, and that's after they've been used for a couple years, died, and ended up in my shop! 


   And what's more is that it's very common for most of these dead consumer electronics to be stock piled by recycling centers and then sold to the highest bidder. Guess who that is? Yes, many of these are sold to anonymous overseas businesses and exported out of the US to be repaired and resold. So here's a breakdown of what we have:

• ACME ELECTRONICS in Singapore manufactures TV's.
• BETA and CAPPA make electronic components in Taiwan and sell to customers like ACME.
• ACME is provided with complete specifications of the parts that BETA and CAPPA have for sale, including the expected life span of the particular parts.
• BETA's capacitors will last for 10 years.
• CAPPA's capacitors will last for 1.5 to 3 years.
• REGARDLESS OF WHICH COSTS MORE, WOULDN'T IT BE TO ACME's BENEFIT TO USE ONLY CAPPA'S CAPACITORS??? 
• ACME chooses to pay more for the capacitors that will not last as long. (hypothetically)
• Now ACME has some guarantee that their TV sales will remain strong every year.
• And sometimes these CAPPA caps will even fail prematurely to the anticipated 1-3 years, but it's  worth it to pay for a few warranty repairs if most others will fail shortly after the warranty.
• And so that there's no question about why the issue continues to happen, ACME refuses to acknowledge the problem. They even instruct their India based support reps to run through an extensive list of dumb-dumb troubleshooting steps until finally the customer gets so upset and frustrated that they just go away.
• Left with few other options but to shell out more money to have it fixed, the customer often chooses to just go buy a new one. 
• And when Walmart has the same size TV, but brand new, for only $600; why pay $200-$500 to fix the old one? 
• Hence...
• More US dollars go to ACME. 
• Old ACME TV goes to the trash, then to recycler.
• Recyclers sell them to the ACME subsidiary "ACME-SALVAGE" for a small fraction of what they were sold to the American consumer for.
• ACME-SALVAGE dumps them in the Pacific Ocean somewhere after they are exported. Why? So they're not repaired/resold to the American consumer, which would hinder the sale of new TV's.

But that's all just speculation on my part. 
That could never happen, right?

REGARDING BAD COMPONENTS USED IN TODAYS ELECTRONICS...
FROM http://www.badcaps.net/pages.php?vid=4

W h a t   C a u s e s   T h i s   D i s a s t e r ?

How did this happen?    The reason this problem exists is because of a large-scale industrial espionage foul-up.  Some companies decided to steal an electrolyte formula from another competitor.  Little be known to them, the stolen formula was incomplete and flawed.  They didn't discover this until it was too late and they had manufactured and distributed literally MILLIONS of these flawed capacitors.  It was way too late for any kind of recall, and even today, these crappy components are being used in new boards.  As I mentioned before, I believe this problem runs much deeper than simply an industrial espionage screw-up, as that incident was exposed years ago, and the problem still exists today.  Nowadays, it just boils down to corporate bean counters cutting corners to save money by using shoddy components. The cause...    This inferior and flawed electrolyte formula was used by a number of component manufacturers that sold to many different, reputable, and well known motherboard manufacturers.  This problem isn't isolated to one particular brand of motherboard, and not even isolated to motherboards alone.  I won't mention brands, but a VERY popular monitor manufacturer has been plagued with RMA's on some of their monitors that were built using these inferior capacitors.  This problem has been reported in computer motherboards, monitors,  televisions, radios, and stereo equipment.  Through my experiences owning a service center, I've personally seen and serviced a large number of 'high-end' equipment that had prematurely failed capacitors. More detailed information...    In more technical terms, this is is what actually happens to the capacitor...in the simplest of terms.  Think of an electrolytic capacitors as a battery.  They are designed to store a charge and release that charge depending on the specific requirements of the circuit.  Inside the capacitor there are two metal plates with dielectric material between them, wrapped in paper, filled with acid (electrolyte), and sealed in its housing or 'canister'.  What happens is the flawed electrolyte prematurely deteriorates and dries up.  When this happens the capacitance value changes, becomes erratic, and can even short completely, which obviously causes the circuit to malfunction.  On your motherboard, this results in system instabilities or complete failure of your board.    From a physical standpoint, the capacitor can display a number of symptoms and even have catastrophic failures.  Catastrophic failure is a rare phenomenon, but it does happen.  The reason is this...  A capacitor canister is completely sealed and air tight.  When the electrolyte dries it turns from a liquid state into a gas.  This gas expands with heat and builds great pressure inside the canister, the theory is the same as a pressure cooker.  Of course the obvious happens when that pressure builds too much, and the capacitor will vent.  This is what causes the capacitor to 'bulge' or swell up.  In a catastrophic failure, the capacitor may actually burst or explode.  It can sound like a firecracker going off or sound similar to air escaping from a car tire, depending on how high the pressure has built.  A physically failing capacitor has an ammonia-like odor (at least that what I thought it smelled like)...  Capacitors that has swollen up are easy to detect, but one that has burst are even more noticeable.  It will usually blow from the top and spew its innards throughout your computer case.  The innards are mostly paper and any remaining electrolyte, but it sure can leave a mess...  Once again, catastrophic failure is a rare phenomenon...  It's not dangerous either, as long as you practice common sense safety precautions!  If you suspect bad caps, don't put your face near them while the system is powered up, and don't eat the paper or electrolyte that they blow out!

Buying a Used Plasma or LCD TV

When it comes to electronics, buying new is generally the safest strategy. However for budgeted consumers, buying a used TV may be the only viable option.

Warranty
At Boise LCD, we provide a 1 year warranty on anything we sell or service. Used TV sets usually don’t come with warranties, unless they’ve been refurbished by the manufacturer in which case there may or may not be a manufacturer warranty. Without a warranty, the most important aspect to look for in a used TV is the age and frequency of use.

Frequency of Use
LCD and Plasma TVs generally last around 50,000-65,000 hours of use. The mileage may vary for less reputable manufacturers. Before purchasing a used TV, make sure to find out when the TV was manufactured and how long it’s been used. Keep in mind that Plasma TVs have a set half life after which their brightness levels halve. LCDs, on the other hand, are backlit by a bulb that is sometimes replaceable.

Price and Purchasing
Since the motivation for purchasing a used TV is price, used TV consumers should look for good deals on reliable machines. Much like buying a used car, it’s important to find the right price for the amount of mileage currently on the machine. Checking online for deals on used TVs is a good place to start. Another place to look for used TVs would be repair shops; oftentimes you can find a refurbished TV at a fraction of the cost of new units. Another possibility is buying a used TV off a friend or a neighbor who’s preparing to a new home. Since Plasma and LCD TVs are becoming popular household furnishings, it’s not uncommon to find good deals for TVs at moving sales among neighbors or friends.

Picture Quality
When buying a used TV, be sure to test out picture quality. Sometimes TV sets that have endured prolonged use may have a dull look. Also make sure to check if there are any burnt pixels on the screen; although these may not impact the picture quality significantly, they can be used as a bargaining position to lower the selling price.

Cables, Settings, Jacks
Always check to see if all audio jacks and cable inputs are functional prior to purchasing a used TV. Also makes sure that the display settings and menus on the TV set are working properly. Since audio jacks and inputs are vital for DVDs and stereo speakers, purchasing a TV with broken inputs is reason for significant price reduction or a pass altogether.

Buying a used TV, with proper research and consideration, can be the perfect solution for price conscious consumers. However keep in mind that some deals, like many things in life, are too good to be true. Be weary of outrageous deals that seem unbelievable, even used TVs have their proper price range. When it comes to purchasing used items, the most important things to consider are mileage and price. The more hours a TV has been used, the shorter its lifespan regardless of how good its condition.