Cleaning LCD sensor possible? (Mitsubishi HC4900) - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 4 Old 03-18-2013, 05:11 AM - Thread Starter
Newbie
 
Jon Appleyard's Avatar
 
Join Date: Mar 2013
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Hi,

I recently purchased an HC4900 for £200 (a bargain in my books). The picture seems good but I do have a couple of 'football' splotches from dust on the sensor. They're mainly visible against pure black. Having read around on here I learned that kicking the lens out of focus reveals the true state of the sensor dust and found there are literally hundreds of specks.

My question is how easy is it to strip the projector down and clean the sensor (or is there another trick)?

I understand the v4 of the firmware ramps the fan speed momentarily on startup in an effort to remove dust but I'm on version 1 and haven't been able to source the newer firmware (Mitsubishi won't email me it).

There's also signs of dust build up on the lens elements. Is that easier to clean?

I'm assuming the outcome would be a cleaner and brighter image. Is that correct? Is it worth the endeavour or could it easily go horribly wrong?

Many thanks,
Jon Appleyard is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old 03-18-2013, 07:41 AM
Advanced Member
 
Bohanna's Avatar
 
Join Date: May 2007
Location: Boston Area
Posts: 637
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 24
The specks are dust that has made it past the fiters and are in the optical path.Usually around the LCD block and behind the front Lens. If you do open the unit do it slowly to make sure you don't rip any case connectors. If you do it right you shouldn't have to disemmemble the unit, Just BE CAREFUL of the ribbon connectors that connect the main board to the LCD Panels. some pivot some slide

Read from Post 8 .

http://www.avsforum.com/t/1369211/any-way-to-diy-cleaning-of-dirty-internal-optics
Bohanna is offline  
post #3 of 4 Old 03-18-2013, 08:00 AM - Thread Starter
Newbie
 
Jon Appleyard's Avatar
 
Join Date: Mar 2013
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Bohanna View Post

The specks are dust that has made it past the fiters and are in the optical path.Usually around the LCD block and behind the front Lens. If you do open the unit do it slowly to make sure you don't rip any case connectors. If you do it right you shouldn't have to disemmemble the unit, Just BE CAREFUL of the ribbon connectors that connect the main board to the LCD Panels. some pivot some slide

Read from Post 8 .

http://www.avsforum.com/t/1369211/any-way-to-diy-cleaning-of-dirty-internal-optics

Thanks very much.

The specks are of a very pure colour which I understood to mean were therefore seated on one or other of the LCD panels themselves. Is this likely to be the case?



This is about 1/3 the area of the whole screen (phone wouldn't focus on anything larger).

I shall thoroughly read the thread you referenced. Thanks again.
Jon Appleyard is offline  
post #4 of 4 Old 03-18-2013, 09:38 AM
Advanced Member
 
Bohanna's Avatar
 
Join Date: May 2007
Location: Boston Area
Posts: 637
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 24
Looks like you got some moisture in the panels along with some dust. you should be able to clean it with out any major problems. Use the fuzzy strips to wipe around the panels and an air hose to blow the dust out. Becareful if you pull the three panels ribbon connectors from the top board. MAKE SURE you know how they release before touching them. some pivit and some slide. It makes a difference so PAY attention. DO NOT REMOVE the Panels from the optical block. They are already factory aligned and if you move a panel or you change ANYTHING you will be screwed.

Bohanna

BTW it doesn't look like your BLUE LCD panel is cooked so you are good to go:)
Bohanna is offline  
Reply Digital Projectors - Under $3,000 USD MSRP

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off