BVM-14G5E wont power on - Page 1
Forum section: electronics / repair

author: Yom
author_rank: Newbie
timestamp: January 15, 2018, 01:33:41 pm
content: I've bought that BVM couple of days ago but i have a problem now but i'm not able to identify the problem alone. I posted that on reddit too.I turn the backswitch ON, it lights the "standby" and it blinks 2 times. After that every lights are blinking (Power/Standbby and Overload). If it try to tap the power button on the front of the monitor, everything stop blinking. and 1time its activating the power led, i head two times clicking around the alimentation and after 3 seconds it return to 3 leds blinking. If it try to retap the power button its stops blinking too, the standby led is active for maybe 3 seconds, no any noise and return to 3 leds blinking. If I retap the power button, its activating power led etc etc... If I switch if off from the back, I head 1 click from alimentation and then it stops.If I'm not clear enough maybe I can film it.I just want to precise that the monitor was working absolutely fine couple of minutes before that problem. It happened just because i holded the power button (in front), and I've put the monitor OFF by the main switch while it was on standby. After that the problem happened.Thats it. Any advice/ideas ?thanks, any help is welcome.

author: Armadillo
author_rank: Super Contributor
timestamp: January 15, 2018, 02:38:29 pm
content: Try reduce the brightness and contrast level to minimum. If the overload LED still blink, then there is a fault in the circuit.It mean the high voltage protection circuit activated to protect the CRT hence overload indicator.Check voltage on connector CN501 pin 1 and 5, the voltage should be around 19.2 to 21V [dot pattern].

author: Yom
author_rank: Newbie
timestamp: January 15, 2018, 04:01:29 pm
content: just checked and i have something between 0.30 and 0.45 it just changes when i put it on and it goes to 0.30 when the leds are blinkingI also got a 7~8V when i head the "clic" when it stoppsbut there is nothing plugged in CN 501

author: Armadillo
author_rank: Super Contributor
timestamp: January 15, 2018, 05:41:34 pm
content: You should introduce yourself and your level of expertise.You know you will be dealing with HV and hot chassis.Before you conclude the HV flyback transformer / driver, you should check the power supply section first.You need to know that I cannot be responsible for your safety and property.

author: Yom
author_rank: Newbie
timestamp: January 15, 2018, 05:47:20 pm
content: I know all that i've been introdiuced in electronics stuff by Arcade stuff (japanese one mostly).But I never repared a power supply myself, the biggest problem i had was a too strong THT/VHT and it turned the cab on security and cutted out the monitor.Here it looks like the same kind of problems, the screen look to be in security mode but i do not know what to do.

author: Armadillo
author_rank: Super Contributor
timestamp: January 15, 2018, 05:52:26 pm
content: Hi, welcome to the board.Be patient abit more, others more able with the power supply board would come to your aid soon.

author: Yom
author_rank: Newbie
timestamp: January 15, 2018, 06:06:19 pm
content: ThanksPatience is not my strong point but I'll do my best ^^edit : just wanted to notice that sometimes I clearly hear the "dong" of a degauss when the power button is up and switches to overload before having 3 leds blinking.

author: Yom
author_rank: Newbie
timestamp: January 16, 2018, 03:40:45 pm
content: Hello, if I can give you fiew precisions concerning this case.The problem appeared after holding the power button for couple of seconds (maybe 7sec) insead of just taping it and turning the monitor off just after with the main power button on the back.Actually i still have the 3 leds blinking.In order what is happening :-Put main power on. Standby led blinking 2 times, and overdrives lights up, the power and it starts blinking (all 3 leds at the same time).-If I press Power button, it stops blinking and power is light up, but after couple of seconds i head degauss sound, and a clic from the alimentation bloc at the same time the overload lights up for 1 sec, then it return to 3 leds blinking.-If I press Power button again, it lights standby and nothing happends, then it returns to 3 leds blinking.-If I press again power its power light.. etc etc... its a cycle.-If i press power and when its the power lighs up, if i activate brightness and contrast button, they light up, and if I try to turn the roll in the opposite way of watch loop, the button power is still activate the time i'm keep rolling them. When I stop rolling, it clics and return to 3 leds blinking.I also noticed that when the monitor is trying to power on, whe the green power led is active and stops, they are a red led on the alimentation board, activate just the time of the "clic" before 3 leds blinking again. Its the red led right in the middle of the alimentation card.I have two leds activated all the time on the alimentation board. (the red led on the left of the board and the green led, not the one on the most right but the other one.I have controlled CN501 pins 1 and 5 with a multimeter, when i start the monitor there is absolutely nothing on it (between 0.30 and 0.45V) and it rises to 7~8V when it turns off (just before 3 blinking led coming).to me the problem is from the Alimentation card or the E board. but i do not know.The monitor was also working aboslutely fine before this "power button holding... i don't understand how i could have break something with just pushing a button. To me it looks locked by a kind of security or something.If those info can help you to help me to know what to do to fix the problem.