Re: ViewSonic VX2260WM not working
Have checked the diodes and they appear to be all right, putting them back in.
Would a dead ccfl cause these symptoms?
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edit:
After re-setting the diodes it seams to be working again, comes on/off as expected and the back lights are all working. Wander what was up, have to see if it keeps working.
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Last edited by robehickman; 06-09-2012, 05:04 AM.
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Re: ViewSonic VX2260WM not working
Lifted the two diodes and confirmed 0v on the ccfl inverter side. To begin with it started up in the same flashing power LED. Took a reading across the big cap which now shows 335v.
At exactly the moment I took the reading on that cap the power LED switched to its usual continual on state, weird. Now when it's plugged/unplugged it goes straight to standby led and the on/off button appears to work as usual.
Voltage across the 5v supplies show 6.15v on USB and 6.13v both of which are stable. Is this too high?
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Re: ViewSonic VX2260WM not working
Thanks for the comments, what (in your opinion) is the probability that changing the caps will fix this, vs it being some other issue.
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Re: ViewSonic VX2260WM not working
@selldoor the ringed item appears undamaged and has markings, however I cannot read them, the fuses are good.
@budm the voltage of that capacitor fluctuates between 25 and 30 volts. They are both 270uf@50v.
The 4.2v reading is only approximate and does fluctuate as mentioned above. It may start higher than this but my multimeter does not update its display that quickly, so it could drop in the interim.
I did power the board up without the logic board earlier(with the lamps connected) and it it tripped the...Last edited by robehickman; 06-08-2012, 02:55 PM.
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Re: ViewSonic VX2260WM not working
The 8 connections listed previously are the only connections between the power board and logic board. Here's some more pictures....
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Re: ViewSonic VX2260WM not working
From what I remember the monitor stopped working one day with the power light flashing, unplugged it and it worked fine the following day until it was turned off. It hasn't worked again since. I can't see anything from the back light at all.
The house RCD frequently trips whenever its raining or there are high winds, it may have failed after this but I can't remember for sure. I've had a computer PSU fail after it tripped, and the dishwasher's motor run cap failed recently after an RCD trip. Though those could just be coincidences....
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Re: ViewSonic VX2260WM not working
Power supply voltages are:
Pin 1 5v actual 4.2v[*]
Pin 2 5v actual 4.2v[*]
Pin 3 5v actual 4.2v[*]
Pin 4 5v actual 4.2v[*]
Pin 5 ground
Pin 6 ground
pin 7 on/off actual floats between 0.8v and 0v
pin 8 brightness actual floats between 0.8v and 0v
[*] starts at this voltage when the monitors power on indicator light flashes then slowly decreases to 0v over a few seconds until the light flashes again.
The power light flashes while the monitor is plugged in and does not...Last edited by robehickman; 06-08-2012, 09:35 AM.
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Re: ViewSonic VX2260WM not working
Hi selldoor, the caps are as follows:
su'scon 2x270uf@50v, 1x47uf@25v, 2x220uf@25v
samxon 3x680uf@25v
The make/rating of the big cap is covered by the glue.
Yes I have a multimeter, the transformer shows 0.775 and 0.780 for those pins, not sure of it's orientation.
Thanks for your help.
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ViewSonic VX2260WM not working
Hello everyone,
I have a ViewSonic VX2260WM monitor which stopped working months back, the power light blinks, quickly shutting off again and nothing else happens. As the PSU caps are a common problem with these things I've taken the board out, but there doesn't appear to be anything wrong with it, at least not visually. Have only a basic understanding of electronics so don't know how to test it.
The power here seams to be good at killing things, I've had several desktop power supplies fail on me also....
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