Philips old projector - image repair - Page 1
Forum section: electronics / repair

author: Matthew98
author_rank: Regular Contributor
timestamp: February 23, 2017, 10:29:33 pm
content: Hello. I have an old projector, which I would be werry happy with, if it wasnt so loud, but mostly of all, if the image would be as it is suppose to be...The green image (which with blue and red image makes the normal image we see) is just off ... Could anyone help me with this ?I would really appreacite itincludng the pic. of menu down there, so its not bad vga cable* Btw it is more off as the time goes...when i got it it was not really that far...

author: The Soulman
author_rank: Super Contributor
timestamp: February 23, 2017, 10:55:22 pm
content: Is this that one from the 80's with the 3 separate lenses?

author: Matthew98
author_rank: Regular Contributor
timestamp: February 24, 2017, 09:08:14 pm
content: I assume not... there is only 1 lens, as far as i can tell, and i got it from school ... So ... 2000s ? I gues...I really ahve no clue what could be doing this...

author: james_s
author_rank: Super Contributor
timestamp: February 24, 2017, 09:18:01 pm
content: Do you know if this is LCD or DLP? It's possible that it's one of those 3-LCD projectors and a mechanical issue may be responsible for the misalignment.

author: Rerouter
author_rank: Super Contributor
timestamp: February 24, 2017, 09:19:40 pm
content: I would suspect internally it may have 3 seperate aiming lenses for the main output, and the green one has become offset (twisted) probably due to rough handling,As its an older model, try searching the part number for a manual, it may include a process to align them.

author: james_s
author_rank: Super Contributor
timestamp: February 24, 2017, 09:26:45 pm
content: Or just take it apart and look. A few years ago I bought several broken DLP projectors for $20-$30 each on ebay, fixed two of them, scrapped one and got some interesting bits. They're not particularly complex from a mechanical standpoint. One of the ones I fixed had a mirror that had come unglued.

author: Matthew98
author_rank: Regular Contributor
timestamp: February 24, 2017, 11:02:14 pm
content: Thanks guysIm not really deep into projectors yet, so its gonna be interesting to learn about them...I would like to make it as a little project for holidays, that we have next week in our country. I will bring it home, take apart and if I fix the image, i might replace the fan with quiter one and reapir or change the awful power supply sound... its like having a power station in room while its on...

author: james_s
author_rank: Super Contributor
timestamp: February 24, 2017, 11:31:33 pm
content: If the power supply is making a sound then there's something wrong with it. Be careful about replacing the fan, these need a LOT of airflow to properly cool the panels and protect them from the intense heat from the lamp. Careful of the lamp too, they operate under very high pressure and can violently rupture at end of life or if struck or damaged.

author: cnqhdszq
author_rank: Regular Contributor
timestamp: February 25, 2017, 12:58:37 am
content: Why didn't take a photo of the projector ?have a look ,so we can know the model .

author: Bushougoma
author_rank: Regular Contributor
timestamp: February 25, 2017, 05:09:05 am
content: These projectors work by splitting the light from the lamp into red, green, and blue which is then sent to 3 individual LCDs. After passing through the LCDs the three colors are then recombined with a cross dichroic prism and the full color image is sent out the lens.If all three LCDs aren't in perfect alignment with one another you'll end up with the image you have it's a convergence issue.There should be convergence adjustment screws or nuts (one for horizontal, vertical, and sometimes diagonal) on the at least 2 of the LCDs (usually the red and blue) so you're aligning the red and blue to the green.Display a convergence test pattern image and turn each adjustment while viewing the pattern to bring the LCD into alignment.Just keep your hands clear of the high voltage power supply since the projector probably uses a metal halide lamp.Hopefully some rough handling just messed up the convergence and there isn't actual physical damage to the optical train.

author: Matthew98
author_rank: Regular Contributor
timestamp: February 25, 2017, 02:24:13 pm
content: Actually I did take a photo, just forgot to check the model ...Sorry...I will try to find those screws.You all are helping me a lot. I was trying to solve this in my country, but ... well, lets say you are helping me a lotI belive its this model : Philips LC4431 cBright SV2 Impact SVGA 1500 ANSI Lumens LCD ProjectorFound it here :http://www.avdeals.com/philipsprojectors/lc4431.htmand tthere is bit more info :http://www.projectorcentral.com/Philips-cBright_SV2.htm"Display Type: 2 cm 3 LCD" So, you were right

author: Bushougoma
author_rank: Regular Contributor
timestamp: February 25, 2017, 04:36:50 pm
content: Depending on the model there may or may not be lock screws (that hold the convergence settings) that you will have to loosen before turning the adjusting screws.

author: Matthew98
author_rank: Regular Contributor
timestamp: March 03, 2017, 04:37:13 pm
content: So, i just taked it apart and i dont see any screws for adjusting :/ Any suggestions ?Also it might not be ossible adjust while running

author: Matthew98
author_rank: Regular Contributor
timestamp: March 03, 2017, 04:41:37 pm
content: This is how its in place

author: Matthew98
author_rank: Regular Contributor
timestamp: March 03, 2017, 07:55:03 pm
content: Ok found itits the 2 golden screws on every lcd

author: james_s
author_rank: Super Contributor
timestamp: March 03, 2017, 07:58:11 pm
content: Before you go twiddling screws, can you get an image on the LCDs with the projector disassembled? I would probably try to see if I had a centered image on all three of them first, you don't want to be trying to adjust away an electronic fault.

author: Matthew98
author_rank: Regular Contributor
timestamp: March 03, 2017, 08:22:58 pm
content: Too late mate...I tried everything.I managed to get colors as they should be, but there is still some wierd ghost image, which has nothing to do with collors. all LCDs display this gost... :/Btw. Have you ever imagined how hard it is to very gently tilt the tiny screen with two players, trying toscreendunno how i managed to get it back again....

author: amyk
author_rank: Super Contributor
timestamp: March 04, 2017, 01:43:10 am
content: That's not a "ghost", you've just put all 3 LCDs out of alignment.How to get them all back into alignment:https://www.manualslib.com/download/905386/Philips-Lc4331-00.htmlis the service manual, it's not your exact model but the adjustment procedure is similar.

author: Bushougoma
author_rank: Regular Contributor
timestamp: March 04, 2017, 02:42:32 am
content: Nice find! The alignment instructions are on page 47.To be fair the convergence was messed up to begin with.To the op you can see here that the green LCD as indicated by the green arrow is clearly out of alignment with the red and blue LCDs.If there isn't enough adjustment in the red and blue LCDs to bring them into alignment with the green something must be bent or broken.

author: james_s
author_rank: Super Contributor
timestamp: March 04, 2017, 06:07:23 am
content: That's what I thought, but looking now it looks like there's green present all across and then a ghost image of extra green offset to the left. Now the convergence is a mess on all the colors though.I think you need to look at the green LCD alone. Maybe slip a piece of black paper in the optical path of the blue and red LCDs so you can see an image of green only.

author: Matthew98
author_rank: Regular Contributor
timestamp: March 25, 2017, 05:24:14 pm
content: Sorry for not responding for such long time. I have to revise a lot at this time for school ...Anyway... it is a software error, or whatever. it is loud and the power supply has to have some error as well, as it makes annoying sound as well. Should I try to repair it, or just give up and take it apart for parts ?(I could use the good quality parts from power supply and fans could come in handy any time..) Thanks.