CurtPalme.com Home Theater Forum

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Hi

I am new to this forum, I have been using crt projectors since 2000 so probably should have joined years ago. Can anyone please help me with this fault. The 800 has been fine for a few years, but developed a gradual fault where the green tube seems to spend more time off than on, it sometimes fires up then usually turns off. The blue tube, very rarely also does the same but the green tube is the main problem. Its got 6500 hrs and otherwise works well.

This occurs from start up even if there's nothing connected to it too so its the projector. Any help advice would be much appreciated!

pjmasks

gjaky · Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary

I'd look for bad solder joint on the neck cards for start.

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Hi,

Great thanks for the advice, i will try to check!

**Curt Palme** · Posted: Fri Jan 12, 2018 1:18 am Post subject:

I don't know anything about this set, as not many were sold in North America, but I agree with gjaky. Also, see if you can swap the neck boards between the blue and green, and see if the problem follows. All three neck boards should be identical, and be swappable between tubes.

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Thanks for the advice Curt and gjaky, I will have a go and check the boards. Hope i get it right!!

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

I was wondering, I have limited experience poking around inside crt projectors, is the neck board area safe to touch, remove swap?... I do open the case and blow away dust regularly, but I have never removed boards?!

gjaky · Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary

Well, if you are not experienced / comfortable with board level repairing then you should not attempt to repair of course!

**Curt Palme** · Posted: Fri Jan 12, 2018 2:54 pm Post subject:

Yes, you're fine. there's no HV stored in the unit 5 minutes after turning it off and unplugging it.

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Is the board attached to the back of each of the tubes? Is it simply unplug, check, ribbons or small solder and re plug? I googled this and there may be pins that hold the board to the tube end that I need to take care with. If its going to be like that that I can have a go, I dabble in basic tinkering inside tape decks, vcrs, dvd players but never these projectors as I do know they hold lots of lethal energy..I am more worried about electric shock, etc. I am not sure which way to go, maybe I could ask a local repair person happy to do it?

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

I've had a poke around, and found the neck boards, seems very tricky to take them off without removing everything in the back of the projector. I noticed one of the connectors attached to a board at the very back of the projector , a set of 3, that runs to the green neck board is not flush on the board, could that be something?

I have tried to attach a photo but its not attaching.... Not sure its there! It's a start to getting it all fixed hopefully.

**Curt Palme** · Posted: Sat Jan 13, 2018 4:42 pm Post subject:

Reseat all connectors, to see if that works. The DWIN projectors were known for that problem, oxidation of the connectors.

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Super thanks Curt I will give it a go!

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

I was amazed to notice how wobbly the little board is at the back of the green tube board. Actually all of the tubes..I haven't removed the green, yet, as there's not much around there to my hand in, only gently wobbled them to straighten the appearance in relation to the tubes. Powered the 800 up and the green tube switched off early on, and has mostly been playing ok. With a bit of playing around I might be able to fix it.

.

**Curt Palme** · Posted: Sun Jan 14, 2018 5:14 pm Post subject:

it does sound like bad connections only. Good news!

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Thanks to all for your support... seems to be working again!

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Green tube still going off Sad

**Curt Palme** · Posted: Thu Jan 18, 2018 3:07 pm Post subject:

Now you need to pull the CRT socket and check for bad solder joints. When the tube goes out, does it go off suddenly, or fade out over about 5 seconds?

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Ok, I will check for dry joints tonight! Many thanks for helping 😊

**Curt Palme** · Posted: Thu Jan 18, 2018 6:33 pm Post subject:

you didn't answer the question. Smile

Also, if you can see the tube neck without taking the set apart, look at the base of the tube for the orange glow of the filament on each tube. See if the green one goes dim or off when the green tube dies. That will tell us something about the failure as well.

pjmasks · Joined: 11 Jan 2018 Posts: 30 Location: Staffordshire U.K.

Ok 👍