3 capacitors (820 uF) deformed, fuse 301 dead (probably 3A) and sc on C 231 (5,2 uF - probably). changed the 3 capacitors with 1000 uF, but 3 A fuse burned again. still have a black screen. any idea or a power supply diagram can help. thanks!
An expert who has written 20 answers of more than 400 characters.
An expert who has answered 20 questions.
Re: syncmaster 740 power supply problem
I would check all the transistors (especially the larger ones) for shorts. If you can separate the power supply from the other circuits (such as by unplugging a connector to other boards), I would do this and see if the fuse still blows. If it doesn't, then the trouble is in another area, perhaps the LCD driver circuits.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
this problem is releted with monitors SMPS (power supply board)
pls find that a capicitor 470/10v or 820/10v is dameged in secondry
side of sm transformer whitch filter +5v and +14 v is rusted or plucked?
then change it or replace the power supply board.
You need to have the 3 capacitors. There is not a 2460uf capacitor, If one of the 3 fail then the other two will still work, if you have just one capacitor and it fails then you have a dead power supply with the first failure.
The flashing power button is caused by a blown power supply. If you can solder then you should be able to do the repair yourself. Check out our web site at: www.ccl-la.com We have a step by step repair guide to repairing this model, showing how to open the case and do the repair. The repair requires replacing 5 small parts, about 15 minutes total time. If you don't want to do the repair yourself we do offer repair services, check our site for details.
I hope this helps, if so please rate our solution.
Lift the front frame. You must try to lift it from the inner side using your fingers (no tools , you may scratch the lcd panel). A little force is necessary especially at the corners. Once you lift the panel from all four sides then the corners will come out.
Note: A common problem with this monitor is the psu. A small number of capacitors fails. You will notice 3 electrolytic capacitors have been deformed and if there is no power you will find a small 3A fuse (looks like a resistor) blown.
There are two reasons why capacitor blow up is higher voltage than it can take or higher temperature than the mark on the capacitor.When I repair psu I always change ALL capacitors,primary and secondary section.Bad capacitor in primary section is usually reason for overvoltage in secondary.Fuse is in power line of 820mF.As I remember they are paralel connected so follow +line back to the diode.There is a small green component looks like resistor betwen diode and capacitors.
Same thing is with other two monitors princip is the same.
Hi this is the way how to examine
what's wrong with your LCD monitors. After you turned it on and the screen
blacked out or stopped working, you have to check that if you can see the image on the screen or
not by shining a flashlight into the screen, not directly but find the best
angle to the screen and take a look very closely. If you can see the icons or
any image, there will be a minor problem. This is because of the lamps inside
screen. Some of them were broken and it is very easy to replace. If you cannot
see anything on the screen, there'll be some problems with inverter board. If you
have soldering tool and want to fix it by yourself, check the caps first. It
may cause this problem. Some caps might show leaking or burn spot on the board
because of too high temp. If you don't have soldering tool, you better go get a
technician to do so.
Hope this help!! If anything I can help you with, feel free to let me know. Thank you,