I had someone suggest this solution: to change the three 470uf 25v capacitors to 50v.
Problem: I have a princeton monitor (VL2018W 20"). i bought it used. it has a 'common' problem that many of this model have; it worked PERFECTLY fine until one day when i turned it on, the monitor started flashing a blank screen, the monitor light was on though. The picture on the screen doesn't come on.
So- would changing those 3 capacitors (i'm supposing the ones associated w/ the display) solve this problem? I know nothing about computers and would just like a second opinion before my husband rips out the original capacitors. thanks SO MUCH for your time!!
We had a power surge and my VL2018W LCD monitor stopped working... blank screen and flashing blue light.
I carefully opened up the back and found the power board (the one the AC plug goes into). There were about 5 electrolytic capacitors that were bulging (but not ruptured). There were 3 with the values listed by the original poster (470uF @ 25V) and 2 with 1000uF @ 10V.
I scrounged a couple of 2200uF@10V caps for the last two and bought 3 470uF @ 35V caps from Radio Shack (P/N 272-1030).
Luckily, the monitor came right back up and seems to be OK. It was out of warranty, so there wasn't a big risk.
Just increasing the working voltage won't do that much for you. If any caps are bad, just replacing them with the same value is good enough, but a higher working voltage won't hurt (usually means a bigger cap).
Good luck.
Rich
I had the same problem as described on previous posts. I have a pair of these princeton monitors and both failed after about a year in exactly the same fashion. I tried replacing the three 470uf caps with 470uF 35volt caps from Radio Shack. Worked like a charm. I was unable to find 50volt rated caps locally but ordered some and will try those on my second monitor. The replacement is easy if you know how to solder. Just be sure to orient the capacitors correctly. Put one in backward and it will make a loud noise and smoke like crazy (AMHIK).
As I saw somewhere by a poster that there are actually 5ea 470uF 25V electrolytic caps and indeed there are. However, you should only need to replace 4 of them. They are all grouped together near the heatsink that has the two TO220 Shotkey Diodes. I did notice the top of each cap which is the safety vent is at (silver with scored cross) was bulged slightly. The fifth cap set off on it's own did not have the bulge. Bulge or not you should replace the set of 4 as I do believe at a 25V rating they are under rated. The Radio Shack part number 272-1030 is only 35V and a 50V might be a better choice however I used the 35V Radio Shack caps and the monitor works well now. The hardest issue was getting the monitor chassis out of the black plastic cabinate. I had to remove the screws that held the front bezel (monitor face surround) in order to get the chassis out. Do take care that there are wires also going to the front panel buttons. Remove the chassis cover that protrudes after disconnecting the 4 cable connectors (2 left, 2 right). The PCB where to find the caps (power supply) is the board where the AC Power Plug goes into. My thanks to this blog as I have two of these monitors with the same issue as I'm sure many more people will be seeing this same issue as the caps breakdown over time.
We had a power surge and my VL2018W LCD monitor stopped working... blank screen and flashing blue light.
I carefully opened up the back and found the power board (the one the AC plug goes into). There were about 5 electrolytic capacitors that were bulging (but not ruptured). There were 3 with the values listed by the original poster (470uF @ 25V) and 2 with 1000uF @ 10V.
I scrounged a couple of 2200uF@10V caps for the last two and bought 3 470uF @ 35V caps from Radio Shack (P/N 272-1030).
Luckily, the monitor came right back up and seems to be OK. It was out of warranty, so there wasn't a big risk.
Just increasing the working voltage won't do that much for you. If any caps are bad, just replacing them with the same value is good enough, but a higher working voltage won't hurt (usually means a bigger cap).
Good luck.
Rich
Fairly radical surgery.. Does he know much about electronics? If not, could be a bad idea. Have you tried attaching the monitor to another pc? Always a good test to prove where the fault is.. Might be the pc's video card. Anyway, I am starting to see a history of power supply problems on the net relating to this type of monitor.. Eg "a blown power inverter card. All five capacitors on it were blown." - So there might be something in it.. Good Luck.
SOURCE: When it's turned on, the light on my Princeton monitor blinks...
I just did this capacitor replacement today after reading these posts. It worked great! I used 470uF
35volt caps from radio shack. There are three 470uF caps two right next to each other and one off by itself on the printed circuit board. The values are easily seen on the side of the capacitors. Open the monitor by removing the screws and prying the halves apart using a large straight edge screwdriver. There is a metal cover over the printed circuit board that will come loose after removing screws around its edge. There are several wire sockets that must be unplugged to allow the circuit board to be flipped over to reveal the capacitors. The board itself is held down with three screws
Once you identify the capacitors, use a fine tipped soldering pencil to melt the solder holding the capacitors in place and remove them. Position the new caps with the dark stripe matching up to the lined marks on the board, carefully apply just enough solder to each terminal to hold the caps in place. Reassemble and you're done.
1,191 views
Usually answered in minutes!
×