CurtPalme.com Home Theater Forum

maxhifi · Joined: 10 Nov 2017 Posts: 5

Hello,

I've been playing with this dinosaur a friend gave me. I understand the technical limitations, but it's interesting all the same, and the curved screen is quite cool looking. Anyway, the projector deveoped a fault, and I'm having difficulty locating any service info. A schematic would go a long way to helping figure out the problem. I think there's an AGC issue. It was previously working perfectly, and then suddenly the brightness became excessive, and the contrast control functions as a brightness control rather than controlling contrast as it should.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4379 Location: Phoenix

Hello

You actually have two problems. These date to 1980 or so, I used to sell them. So all of the service manuals are in landfills by now. And if you could diagnose the problem exactly, the part you need hasn't been made for twenty years. Electrohome tv chassis.

**kal** · Posted: Thu Jun 27, 2019 1:24 pm Post subject:

maxhifi · Joined: 10 Nov 2017 Posts: 5

I managed to find one on www.stereomanuals.com - should be here in a week or so.

I am familiar with servicing vintage electronics, and the issues with parts supply. So far I've narrowed the problem down to not being the tubes, the flyback, the voltage multiplier, or the yokes - basically, it's got to be some small passive parts which actually are available, rather than a major component which would be a showstopper. It's extremely slow to troubleshoot when I have to reverse engineer everything instead of just following a service manual, though.

The electrohome chassis is literally identical to their 25" console TVs of the era, and there's separate add on boards for the convergence, pattern generator, and other things specific to it being in a projector and not a TV. Worst case scenario I could probably find an old console somewhere and steal parts.

I should add that repairing this thing is more about because I can, and not because the result will be financially worth it - I'm fully aware that one of those $99 wal mart projectors will likely have a better picture.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4379 Location: Phoenix

Guys

If you are fixing it for laughs.......that's all you'll get! 4:3 composite video, maybe 800 x 600

maxhifi · Joined: 10 Nov 2017 Posts: 5

**kal** · Posted: Thu Jun 27, 2019 9:40 pm Post subject:

maxhifi · Joined: 10 Nov 2017 Posts: 5

HaydnG90 · Joined: 22 May 2006 Posts: 1335

**kal** · Posted: Thu Jun 27, 2019 11:57 pm Post subject:

**AnalogRocks** · Posted: Fri Jun 28, 2019 1:12 am Post subject:

**kal** · Posted: Fri Jun 28, 2019 2:42 am Post subject:

Was done more as a comment against Tim who thinks a 480i projector is a waste of time. Wink

I disagree. Run whatever you want for whatever reasons you want I say...

Kal

**AnalogRocks** · Posted: Fri Jun 28, 2019 3:38 am Post subject:

maxhifi · Joined: 10 Nov 2017 Posts: 5

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4379 Location: Phoenix

Kal.........

"Many would argue that using *any* CRT projector in 2019 should only be done for laughs."

How did you GET this job? LOL

HaydnG90 · Joined: 22 May 2006 Posts: 1335

Watching Mortal Engines on my 'inferior' G90 with MP BA mods @1080/72 with blacks and saturation to die for. I, in no way, feel like I'm missing out. When time comes and the 4K lasers like the Sony VPL-VW995ES or next gen are sub $10K I'll probably consider one. The decrepit CRT won't live forever.

**kal** · Posted: Sat Jun 29, 2019 1:31 pm Post subject: