Question about ViewSonic VG150 15" LCD Monitor

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Switching it on/off

The monitor seemed never to switch on so I replaced the switch with a Radio Shack momentary pushbutton switch. All well? No - not quite. I'm utterly baffled! To switch the monitor on, the switch does not work at all. the switch is fine, the soldering is fine, the wires are fine. I checked them all with my meter. I switch the monitor on by crossing the soldered joints on the mainboard with a screwdriver. I can then switch the monitor off using the switch I put in. Resistance on the wires and switch are negligible. Holding the switch down for a long time, pumping it etc have no effect on switching the monitor on. One tap is all I need on the switch to turn it off. I can get the monitor on every time by using the screwdriver method. Any explanations to this bizarre behaviour? I'm all set to toss the thing in the trash if this continues.

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Re: Switching it on/off

I recently (last week) replaced an LCD screen on this model monitor and I have the remnants of the parts monitor still. If you think the problem is the circuit board with the switches, I could send you that part *NO CHARGE* (if you're in USA). I can't post contact information, though, or I'll get in trouble. Don't know how to continue at this point. Do you want to try posting contact information?

Posted on Aug 21, 2007

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I have bad 680uf 16v capacitor can i replace it with 1000uf 16v capacitor


The 1000uf is to far out of tolerance to work correctly. You also need to be sure that the capacitors you use are rated correctly for use in high speed switching power supplies. The parts will need to be low ESR, high temp and high ripple current. replacement parts from places like Radio Shack or Fry's will not work right and could damage your power supply board. Here is a link to a page that explains more about getting the correct capacitors for this type of repair.

You should also charge all of the capacitors on the power supply board because when one shorts out it put a stress and the others and they will start to fail soon too. Replace them all while you are there so you don't have to reopen the case in a month and replace the rest.

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I have a samsung 920n and the power light just keeps flashing green when i switch on and there is an intermittent clicking noise every 2 to 3 seconds.. i replaced all caps (one 470uf was damaged) exce

Are you sure that you used the correct type of capacitors in the repair? They need to be low ESR, High Temp and High ripple current. Capacitors from places like Radio Shack or FRYs will not work because they are only general purpose and the switching power supply can not work right with them installed and they could even damage the electronics on the board. Here is some more information on getting the right capacitors.

Jun 13, 2012 | Samsung Computer Monitors

1 Answer


You need to find out if you do have 12vdc and 5vdc for the inverter circuits and logic board, I usually repalce the caps in a set not just the bulging one since bad cap can look normal but has high ESR, you need to use low ESR type cap in switching power supply, generic Radio Shack will not work or last very long. I use Panasonic FM/FC series for all my repair works because it has low ESR, 105c and high ripple current and high rated life.

Basic LCD monitor and TV troubleshooting guide:

Failed TV, Monitors, capacitors, and lamps pictures:

Learn about bad caps:
Capacitors kit: he can make you a set of caps for you.

Replacement board:
Please post back what you find.

Nov 10, 2010 | Dell E176FP 17" LCD Monitor

1 Answer

Replaced all capacitors as they were the begining the monitor would stay on for a second and then go the monitor will not light up at all...there was a piece of solder that grounded...

Here are the datasheets for the rectifiers, not regulators:

These are typically used, if memory serves, as part of a switching power supply. If these are damaged, then likely the switching mosfet, and possibly the switchmode regulator IC is damaged as well.

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Samsung syncmaster 910mp TV connection

I believe you are describing this connector adapter. catalog number 2780265

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because of moiture pushbutton switch were conduct there for replace pushbutton switch and see result

Aug 15, 2008 | HP Pavilion F1703 17" LCD Monitor

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Mag Innovision 765S power supply light blinks and monitor power led blinks and no picture

I'd suggest looking at the mainboard. I assume the blink is rapid? A slow on, followed by a short off and back on again is normal. The fast blink thing is a mainboard issue, and the absence of blink (or light) is power "supply dead."

There is a problem transistor on the mainboard that seems to be the problem most of the time. Replacing it takes about 5 minutes if you have the tools and the talent, and the parts cost under 3 bucks at Radio Shack. Just pick up a pack of NPN switching transistors and de-solder / solder your way to a working monitor. There's usually only one on the board, so it's easy to spot.

Nov 18, 2007 | Mag Innovision InnoVision LT 765S 17" Flat...

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Dead Monitor

Most of the time with these things, the problem spot is not any of the stuff you mentioned. It's a stupid little switching transistor soldered to the mainboard. You can get a ten pack at Radio Shack for like 3 bucks, and there is seldom more than one on the board.

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