| JohnG |
I apologize if this is considered OT.
I have recently been given an Acer FP855 LCD monitor (18"). It has the following problem:
The screen flashes, i.e. it remains dark except for a brief flash every second or so, where it appears to properly display the screen. My guess is that something is wrong with the backlight, but I haven't had a chance to open it up yet.
I'm just looking for ideas, if anyone has run into this problem. I have searched the web without much luck, except for one unanswered request along similiar lines as mine. Any help would be appreciated.
Thanks,
John |
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| Psionic |
Actually, this is a long shot but I have an acer 17" CRT monitor which does kind of the same thing. I turn it on, and then it turn off after a few seconds it goes off
On an offnote, if you are going to use an LCD of that size, you will not be able to use the fresnel from an OHP cause it will be too small. You may be interested in this auction though:
http://cgi.ebay.com/ws/eBayISAPI.dl...&category=30076
if it has ended then it may be up again its been up a few times. |
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| smithmarkd |
Did you identify this problem? I have the same panel/same problem.
Thanks
Mark |
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| 18wheeler |
either backlight or invertor is bad. replacement might be expensive.
if there is no pcb board in the way, you can either buy a big fresnel and turn it into a projector panel; or use a few flourencent bulbs to make a light box, and use it as a back light replacment. there are LCD's use this idea, like CMV1515, 1512 and rebadged CMVs. |
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| thaddl |
| I had the same problem with the same monitor and model number. Unforutnately it just ran out of warrenty. The monitor would flash on and then off every second or so. The problem had to do with power getting to the screen. I could tell this because if i made an adjustment (birghtness, etc.) it would only adujst while the screen was lit. I fixed this by replacing 2 capacitors just under the back panel. They were labeled c704 and c708. They had obviously "popped" , the tops were raised and bloated, etc. I had these caps on hand but I'm sure they are easy to find. Radio Shack may even have them for no more than a couple bucks each. Pretty cheap fix and worth a try. I hope this helps. |
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| faithblinded |
I would get on eBay and buy a dual tube white Cold Cathode kit for PC case modding. These I believe are the same thing alot of lcds use as backlights.
Or strip it down and build a high res projector.
Get on the Big Fresnel thread and get one if that's your plan though. |
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| JohnG |
Thanks for the lead, thaddl!
When I got the monitor, the only obvious discoloration was on the backlight ballast boards, but I didn't check with a scope or anything.
John |
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| JohnG |
A million thanks, thaddl! It worked, and I now have a nice 18" LCD monitor for my computer. I found it in the garbage, no less...
John |
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| MacGuru |
A million, billion, trillian thanks, thaddl!
Again, Thanks:smash: |
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| killchain |
Hello,
I was recently given an Acer FB855 LCD Display, and it has the same "strobing" problem that the previous poster has. I opened up the back panel and sure enough, two of the 1000µF 25V capacitors have bloated tops and one has even leaked from the top, a sort of reddish rust colored substance. I was wondering if this was a telltale sign of a bad capacitor?
My main question, though is where can I find this specific capacitor? I've checked all of the local places where I live and they look at me like I'm trying to buy military weapons, heh. Any hints on where to pick up a few of them? I don't want to lose this monitor because of a few blown capacitors.
Much thanks in advance,
KC |
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| thaddl |
| Yes, that is exactly the same symtom that I've seen. Those caps are toast. I've had 3 of these montitors go bad with the same problem.Radio Shack has a cap that I used to fix the last one. It's 35 V is an overkill, but won't harm anything. At a $1.59 ea. you should try it. |
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| killchain |
So it's safe to use a 1000 µf 35v capicitor?
...and we'll see if my local radioshack does indeed have one. Or three. :P |
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| killchain |
| OMG haha, I looklater and see you posted a link. Thank you so much, I owe you one! :D |
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| killchain |
| Well, I got the capacitors you listed for me at radioshack today, and I popped them into the circuit board, and lo and behold I am now typing this on my Acer FB855! Thank you so much, Thaddl! :D |
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| kak2112 |
Hi everyone...I just found this forum because of this issue some people are having with that fp855. I've had the same problem. I opened mine up and the caps that you are talking about seem to be OK, however another part of the power supply seems to be damaged/browned (like it was burning!). I took a few (admittedly, bad) pictures of it. I placed an arrow pointing to where the problem seems to be. The pics can be viewed @ http://www.cs.rit.edu/~kak2112/fp855/
The brown'ed area is around the 2 large yellow-ish rectangular-ish boxes. The 3 caps that everyone says are the problem seem to be OK. The two of them are EVER-SO-SLIGHTLY buldged, but not badly at all. Nothing is oozing out. I don't think these are the problem (but I'm no electrician!).
If anyone has any idea on how to fix this or how to order a new power supply, that would be greatly appreciated. |
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| aceisaneight |
| my problem is that the led will light up green like a signal is being received but the screen remains blank. my capacitors look fine. would this still be a power suplly issue or do u think changing the capacitors will help? |
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| aceisaneight |
| where can i get a replacement power supply? |
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