Thanks for your response on my monitor problem. I have looked long and hard at the electrolytic capacitors, but can see no bulging or leaking. Could they still be at fault or should I look elsewhere. I have had experience in soldering and the like so is not a problem to do, but I don't want to start pulling stuff apart until I am confident I have homed in on the problem. Any further comments?
An expert who has achieved level 2 by getting 100 points
An expert that got 5 achievements.
An expert who has written 20 answers of more than 400 characters.
An expert who has answered 20 questions.
Re: Benq 937s monitor problem
They can most definitely still be at fault - here's where it becomes tricky. To properly test electrolytic capacitors you need an ESR meter - not cheap - or you could spend the $150 on a complete set of replacement caps instead. You're really rolling the dice either way, because it might turn out to be a bad transformer or something completely different. I've fixed 15-20 LCD monitors and the problem is almost always a cap, some are visible and easy fixes, others have stumped me for days and days until I just start replacing caps in the hopes of lucking out.
One of the things I tried when I first started doing it was searching google for the model number of the monitor to see if anyone else had fixed one and might know which parts were bad.
Wish I could help more, sorry it didn't end up being an easy fix. Maybe it's worth calling the computer/TV repair shop and asking how much they'd charge to fix a LCD power issue.
- 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.
teo6925, "Switch-mode-power-supply" is in partial shutdown mode. Can you see any electrolytic filter capacitors that have a slight "swelling" to their tops? They should be flat!! You may also need to inspect all the soldered component connections very closely for cold, thermally intermittant, "frosty" looking solder joint connections. May need large magnifying glass or 10x to 20x inspection microscope to locate these thermal/vibration "fractures" and then resolder them! If you have a capacitor problem, then you will need to carefully remove and replace with new ones. If you are novice at soldering I suggest that you document your work with digital camera or video tape so you can get everything back together with no "leftover" pieces! Teo, all you need to do to find out how BAD the problem of poorly manufactured capacitors is would be to search WEB for BAD CAPACITORS!!! Look for pic's of ELITE capacitors or CAPXON brand. You will be stunned beyond belief!!! Reading is free!! READ, READ, READ. Let us know what you find and do additional comment here on FIXYA. 12fixlouie
Bulging or "blown" electrolytic capacitors are a common problem with LCD monitors. If you replaced them with correct parts (voltage rating) then one of two situations comes to mind: 1. Electrolytic caps are polarized, if you install them backwards they will blow quickly. 2. The voltage the circuit provides exceeds the rating of the cap. A 5 volt cap in a 12 volt circuit will blow quickly. The voltage regulation circuit may not be working. Monitor Mike
There is usually an identical resistor somewhere else on the circuit board, so if you cannot read the colors of the burnt one, you can read the colors from an identical resistor on the same board. If you just replace the resistor, it will probably just burn out again or damage another component, you have to find the cause of the resistor burning out, most likely an electrolytic capacitor failing. Look for bloated or seeping capacitors and replace those as well. Also look for broken or burnt toroid coils.
This is most probably cause by one or more Faulty Electrolytic Capacitors, I find these are the MOST commonest form of "Fault" in these LCD's TFT's units. I ususally simply replace "On Spec" all High Value Electros, in fact ALL Electro's are suspect and often I just "Shotgun" and replace 'em all. Usually fixes all problems. Always use High Temperature Caps.