Optoma H55 Gone Crazy - Page 1
Forum section: electronics / repair

author: hgg
author_rank: Frequent Contributor
timestamp: September 19, 2014, 12:53:33 pm
content: Hi,I have an Optoma H55 single chip DLP projector and recently started doing crazy stuff.Sometimes it has a yellowish/red tint to everything. Blue is missing. Its not a bad connection becauseit does the same on its menu items without any signal connected. Lamp its pretty bright.Other times when I switch it on, the screen flashes sometimes and then it switches off.Other times it works ok.Just now, it totally stopped working... I shaked the projector in my hands and now itstopped working. You press the power on button, the led lights up but the lamp andfans wont. When I try to measure the resistance of the lamp I don't get any reading.Do you have any ideas what to look for? Colour wheel, Video circuity, Power supply?I've opened the unit but I cannot locate a colour wheel.I cannot find any service manual either.Thank you.George.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: September 19, 2014, 07:35:22 pm
content: Since the lamp is an ARC lamp, no resistance measured is correct. But unfortunately, that does not necessarily mean a good lamp... and you could also have problems in the Lamp connector(overheated),ballast circuit, PS, etc. I have an H77, and an H76, the H76 got a new lamp a few hundred hours ago, but no idea the hours on the old lamp as it was purchased used..."These projector lamps do not have a filament, but light is created by an arc between two electrodes that ignite the gases in the arc tube. Over time your projector lamp will become dimmer. At some point it will become so weak that the ballast will be unable to ignite the gases in the arc tube. The ballast will continue to try to ignite the lamp until the arc tube gets so hot that it shatters inside your projector. Here is a good indicator that your projector lamp needs to be replaced: broken glass in your projector."http://allprojectorlampz.blogspot.com/2010/06/is-my-projector-broken-or-do-i-just.html

author: hgg
author_rank: Frequent Contributor
timestamp: September 19, 2014, 08:10:08 pm
content: Hi,I don't think there is a problem with the lamp. It was very bright when it was working.I've read that if there is a problem with the colour wheel then the projector will notturn on the lamp. I might have to disassemble it completely because I cannot findthe location of the colour wheel.Any ideas where to find the service manual ?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: September 19, 2014, 09:39:30 pm
content: If Optoma will sell you one, that is probably going to be your single source. If you can find an Authorized Warranty Station you may be able to pay them something for copies, or order one for you, if Optoma will not sell direct to you.Lamps are the most common failure, and the associated circuits. Heat is your enemy.Good Luck, and if you are successful finding a manual please post your source here for others.

author: hgg
author_rank: Frequent Contributor
timestamp: September 20, 2014, 07:33:14 am
content: We don't have an official service in Greece.I think I will take it apart. Very messy construction though.Anyway, thanks.