Hello,
I have a monitor Mitsubishi Diamond Pro 2060u which is having a random problem.
Sometimes, it does not turn on. Sometimes I try a couple of times (pushing the On/Off button) and it started. Sometimes I try many times and it does not turn on.
When it star ok there is a metallic sound followed by a click and the green light is on.
When it does not turn on there is not any sound and the light is off.
Could it be a problem with the On/Off button? Or, Could it be a problem related with some capacitors in the power supply board?
I would appreciate any help with this problem.
Thanks and best regards,
Javier Martin
power
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Hi!
Power button or bubbled capacitors in power supply or capacitor(s) near processor
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Hello, thanks for the advice.
Now it is fault all of the time so I decided to dismount it. This is what I have found:
The power switch is right. It closes and open all the time.
The power supply board (CT920B58401) does not look bad except for the resistors R922, R923 and R941 which seem that are overheated (see picture 1). I have dismounted them and the value of all of them is right: around 21KOhms (their value are 22K, 2 W).
I have been checking the service manual and I am not sure if I understand it right (see Service Manual, 1.1.4 (4)). With nothing connected on the secondary side (the connector to the main PCB is unplugged) still I should have the +5 V. Am I right?
I have just connected the 220 Vac, the power switch is working, the output of the rectifier bridge is around 320 Vcc, but there is not +5V.
On the service manual there is not a detailed diagram of this board. I have the diagram of the power supply of the monitor 2070 and seems similar but I guess they are not totally equal.
I do not know what else to do. Do I change the electrolytic capacitors (neither of them look bad) ? All of them (see picture)?
The value of the capacitors are:
C901: 450 V/ 220 uF
C915: 35 V / 47 uF
C930: 35 V / 56 uF
C931: 50 V / 4.7 uF
C935: 50 V / 4.7 uF
C961: 250 V / 100 uF
C963: 100 V / 82 uF
C964: 25 V / 820 uF
C965: 25 V / 820 uF
C967: 100 V / 22 uF
C968: 16 V / 100 uF
C969: 16 V / 120 uF
C971: 10 V / 2200 uF
C972: 16 V / 220 uF
Any help would be very appreciate.
Thanks and best regards,
Javier Martin
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https://resistorcolorcodecalc.com/
4
https://i.imgur.com/6rZYLOR.png
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Hello zsugori. Thanks for your reply but I do not understand what you mean.
Regards,
Javier Martin
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