(1) The backlight looks to turn on for about one second (makes hissing sound), but there is no image. Doing the flashlight test after this shows the LCD to be working.
Before replacing the bad caps, the desktop image did show briefly before backlight turned off.
There are two sets of connectors on the inverter board that if unplugged, eliminate the hissing sound on start up. If just one of the pairs (either one) is plugged in, there's no hissing and backlight still turns on then off.
(2) F1 reads 0.2 ohms.
(3) I may need to replace the 3 caps on the inverter board and the 6.3V 1000uF cap on the logic board because they have a lower ripple current rating than original cap (didn't know about this when I soldered them in)
Okay, just to confirm, the current problem is that there is no backlight at all (not even a flash when first powered on)?
When you tested F1, what ohms reading did you get? A good fuse measures less than 1.0 ohms.
PS. Great photos
(1) The backlight looks to turn on for about one second (makes hissing sound), but there is no image. Doing the flashlight test after this shows the LCD to be working.
Before replacing the bad caps, the desktop image did show briefly before backlight turned off.
There are two sets of connectors on the inverter board that if unplugged, eliminate the hissing sound on start up. If just one of the pairs (either one) is plugged in, there's no hissing and backlight still turns on then off.
(2) F1 reads 0.2 ohms.
(3) I may need to replace the 3 caps on the inverter board and the 6.3V 1000uF cap on the logic board because they have a lower ripple current rating than original cap (didn't know about this when I soldered them in)
OK, I bought a multimeter and have checked a few things.
- F1 seems to be alright.
- I checked the diodes in the areas of interest and they're behaving as expected.
- All other diodes on the inverter were checked and it seems that D15 and D16 behave differently (they are both high speed double diodes A7W: ) Using diode testing mode I measured the following values:
For D16:
Anode +probe, CommonConnection 0.626V, Cathode 0.354V
Anode -probe, CommonConnection 0.977V, Cathode 0.354V
CommonConnection +probe, Cathode 0.622V
CommonConnection -probe, Cathode 0.975V
If you take these values and compare them to D6(A7W):
Anode +probe, CommonConnection 0.613V, Cathode 1.044V
Anode -probe, CommonConnection OL, Cathode OL
CommonConnection +probe, Cathode 0.614V
CommonConnection -probe, Cathode OL
and D6(A7W):
Anode +probe, CommonConnection 0.120V, Cathode 0.735V
Anode -probe, CommonConnection 0.120V, Cathode OL
CommonConnection +probe, Cathode 0.619V
CommonConnection -probe, Cathode OL
Do these values seem right? I couldn't follow the traces very well since the silk screening obfuscates them in the densely populated areas.
I'm currently working on this monitor and I'm having a bit of trouble identifying which board I need to replace the caps on. I recapped every capacitor that looked blown but the monitor is still dead (power comes on, green light near power button, no picture).
I replaced 3 on the inverter board, and 8 on the logic board. The power board (?) looked okay so I didn't touch it.
What do you guys think? Is the black display caused by poor soldering/recapping on my part or is it the power board that's the problem since I haven't worked on it yet.
Thanks for your help!
Have you measured the voltages out of the power board? Have you verified power is getting to the inverter? Is the fuse on the inverter good? If you shine a bright light on the display can you see an image?
I'm currently working on this monitor and I'm having a bit of trouble identifying which board I need to replace the caps on. I recapped every capacitor that looked blown but the monitor is still dead (power comes on, green light near power button, no picture).
I replaced 3 on the inverter board, and 8 on the logic board. The power board (?) looked okay so I didn't touch it.
What do you guys think? Is the black display caused by poor soldering/recapping on my part or is it the power board that's the problem since I haven't worked on it yet.
I just finished replacing some capacitors on my VP2030b and I can now report success!
Since approximately half a year ago, the monitor has been slow(>3 mins) to turn on the back light. And one day a few weeks ago it stopped working all together.
It's obvious this monitor was never intended to be opened, it felt very wrong to pry open the front bezel with all the force that was required. But once that was off, the rest was rather easy.
I ended up replacing all bulging capacitors that I could find.
These were located on the inverter board and the main board.
I found it to be very tricky to locate 180 uF capacitors, so I went for three 220 uF capacitors with low ESR instead.
On the main board I replaced the following:
* Four 330 uF capacitors
* Six 100 uF capacitors
* Two 1000 uF capacitors
The replacements were also of low ESR.
All components was ordered from Elfa:
* 4 x 67-233-73
* 6 x 67-228-70
* 2 x 67-042-60
* 3 x 67-042-74
Thanks for all the inspiring posts in this thread!
But remember that electrolytic capacitors in general have a 20% tolerance on the capacitance, so don't worry if you cannot locate an exact replacement. Choosing one of slightly higher value works just as well!
Are there any fuses in the area of VIN of the inverter board?
Yes, there's F1 with a "TP" label on it, so I'm certain that's a fuse. It bridges the trace where the inverter board connects to the logic board via pins 1, 2, and 3 (labeled as VIN on the top side). I don't have a multimeter yet but I'm going to buy one soon so I can test F1. If F1 is OK, there are a few areas of possible interest. I'm attaching a picture of the bottom of the inverter board and close up shots of the areas of interest, maybe the diodes are over heating or something?
I would suspect the hissing sound was either A transformer, or a ccfl that had a poor connection on one of the wires.Are there any fuses in the area of VIN of the inverter board?
(1) I am having this same issue (black screen on power up then green light stays on) and have gone through and replaced the three caps on the inverter and the four (within red circles in lucky's picture). All where visually identified as bad, except for one on the logic board (replaced anyway).
I was given the monitor as it wouldn't work. When I got it, pushing the front power button would: turn on the LED to an amber color, then turn on the LCD and back light with the LED switching to green, display desktop while making hissing sound from inverter area(?). Back light would then power off and LED stay green. I was able to see the LCD was still active by shining a flashlight into the LCD to dimly illuminate it.
After replacing caps, the same thing happens but there's no image displayed at start up. LCD is still active when I do the flashlight test. Does this mean I improperly soldered the caps? Did anyone else have the weird hissing sound?
(2) After ordering and soldering the caps I found this forum/topic and have noticed that there are a few issues with the caps I used (didn't know about ripple or ESR). For the caps on the inverter, I used the same ones as splinter (EEU-FC1v181) which have a lower ripple current rating than the originals, but he seems to have not had any issues with his yet and got his monitor working. On the logic board, the three 330uF caps I used are within spec but the 6.3V 1000uF cap (EE/U-FC0J102) is about 200(units?) lower on the ripple current rating and was too fat to fit (d'oh!) so I soldered it in a raised position which allowed it to fit. How much of an issue is ripple current rating and how would this effect the monitor?
take a blow dryer (with the heat setting turned off) and concentrate the cool air on certain parts of the board to isolate the problem.
In post #75, the picture with the rubycon 1000uF 25V cap, there is some discoloration. I would maybe start with cooling down that area with a blow dryer first?
If there is a chip underneath, it could be running hot?
It's definitely heat related -- it starts after a minute or so of the monitor being on and I can then make it go away by cooling the back with a fan (and then make it come back by taking the fan away)
I'm the original owner, bought in July 2006. Probably on ~4 hours a day? I let windows put it into standby when I'm not using it.
Don't remember any dodgy colours or anything out of the ordinary before the flickering started.
I'll open it up again tomorrow and inspect / take pics of the boards
Hmmm.....maybe once you open it up again, you can take a blow dryer (with the heat setting turned off) and concentrate the cool air on certain parts of the board to isolate the problem. Also, try doing the same thing on the main board (logic card).
It's definitely heat related -- it starts after a minute or so of the monitor being on and I can then make it go away by cooling the back with a fan (and then make it come back by taking the fan away)
I'm the original owner, bought in July 2006. Probably on ~4 hours a day? I let windows put it into standby when I'm not using it.
Don't remember any dodgy colours or anything out of the ordinary before the flickering started.
I'll open it up again tomorrow and inspect / take pics of the boards
Take your boards to a window on a sunny day, turn flash off, and use macro mode. Take a top down view of all your boards (front and back). Make sure the photo is legible so that we can read the PCB printing clearly. A shutter speed of 1/125 or faster will produce nice clear focus pictures. Try to get a photo that is 2000x2000 resolution or as close as possible.
I have 3x vp2030b. One just briefly went blink-blink-blink and then when turned off for the night would not turn on in the morning.
On pulling the boards I found the bad caps almost instantly and came looking here for help and found a great surprise with the info in this and the other vp2030b thread. THANKYOU. New caps have been ordered from farnell.
However.... I have some pretty severe scorching in the PSU.
The two caps that are oriented vertically either side of the heatsink have clearly got blown tops.
The grey resistor has clearly got frighteningly hot and scorched the PCB.
I have ordered new CAPs (220uf 25V left of the heatsink and 470uf 16v on the right) but now I'm wondering if there are other components that are likely to have blown/fried.
I'm a dab-hand with a soldering iron and I can work a multi-meter but I dont have the knowledge/expertise to test components.
Q1: I know resistors are pretty robust - but should I be replacing this one? (value? type? farnell cat number?)
Q2: There is a diode above and in the same line as the resistor that looks like its either had a lot of current passing through it and its got hot..or its just been passively heatsinking from the hot resistor and also got hot - should I just aim to replace this also... how do I work out what type of diode it is..or can someone tell me?
Q3: Can I test the PSU without hooking it up to the monitor (ie like you can with computer PSU by bridging the ground (pins 3,4) and power-on pin (pin 8) of the 8-pin connector on the side of hte PSU board (CN1)?
TIA for any help - pics below.
( I have also bought CAPs for the inverter and the larger ones on the mainboard that seem to cause people problems. I bought enough for all 3 monitors even though 2 of them are working fine...I suspect not for much longer so a preemptive strike may be in order).
I am wondering if there might be an A.C. voltage ripple problem?
I cannot find it but some just posted a A.C. milivolt reading that was the point of being suspect.He was reading it with his dvm.
Al.
I am wondering if there might be an A.C. voltage ripple problem?
I cannot find it but some just posted a A.C. milivolt reading that was the point of being suspect.He was reading it with his dvm.
Al.
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