CurtPalme.com Home Theater Forum

Gypsy · Joined: 14 Sep 2017 Posts: 38 Location: Tolaria

Any help and thoughts on things to check are appreciated. Main goal is assessing if the electronics are functional.

The projector starts, red and blue have visible output, but the green tube seems dead. Fans run and the menu and an internal test pattern displayed (on blue/red). I pulled and reseated the neckboard. All boards in the tube section have also been pulled and reseated as well. I haven't taken off the lenses, checked the boards in the front of the chassis, checked all cables within the tube area, or tried removing the tube.

The green tube has extreme wear and would need to be replaced anyway, is it worth continuing to try and troubleshoot? Can boards and parts be swapped between G70s freely?

**Curt Palme** · Posted: Fri Feb 13, 2026 6:14 am Post subject:

Check the CRT socket to make sure the green tube filament is lit. I've seen a blue tube with a cracked solder joint on the filament in a G90 once, so that's possible. If the green tube filament is lit, then change the video amp between tubes. All three should be identical. Most likely the green video output amp is dead.

Gypsy · Joined: 14 Sep 2017 Posts: 38 Location: Tolaria

Thanks. Where are the amps in question located?

**kal** · Posted: Fri Feb 13, 2026 5:19 pm Post subject:

The video output amplifiers are on the circuit board that houses the CRT sockets.

See: https://www.curtpalme.com/SonyG70_Layout4.shtm

Kal

Gypsy · Joined: 14 Sep 2017 Posts: 38 Location: Tolaria

Thank you. Right where I hoped it wouldn't be Laughing

. I presume pulling and swapping tubes is the simplest way of checking? As for the filament, I would power on CRT and look at the end of the neck near the socket?

**kal** · Posted: Fri Feb 13, 2026 7:36 pm Post subject:

I can't answer those questions but maybe others can. Good luck!

Kal