View Full Version : AT&T PC 6300 / Olivetti M24 Color Monitor CRT318H Help!

May 14th, 2016, 01:14 PM

I recently picked up an AT&T PC 6300 (A.K.A. Olivetti M24) with keyboard, monochrome and color monitors.

The monochrome monitor works, the color monitor doesn't. So far I found a bad thermal fuse. Upon replacement I still don't have an image on the screen, but I do have more voltages showing up on the power supply board and hear the faint sound of something similar to High Voltage. The caps on the monitor are all within proper ESR range and I've done a quick once-over looking for other obviously/not-so-obviously bad components. I'd like to dig further but can't seem to figure out what this monitor actually is.

I've gotten as far as figuring out that it's made by Hitachi based on the FCC ID. https://fccid.io/ABL9678503CD

My ultimate goal is to find one of a few things... I really want a technical resource of some sort for this monitor, schematics or a service manual. Even a non-AT&T model number would help things, as the AT&T model number (CRT318H) isn't helping me find technical information on this monitor.

I've been Googling my heart out on this. I have gone down a few pathways to figure out what monitor I have here, but my Google-Fu is failing. I was hoping someone else here might have some knowledge they can drop to assist.

Here are two horrible-quality images I found online in case that helps anyone:
31231 31230


May 14th, 2016, 01:26 PM
I think the AT&T 6300/M24 monitors were made by Hantarex. You might try a web search for some of those. The last time I looked, I found the one I was looking for.

May 15th, 2016, 11:42 AM
If you find the schematic, please post it -- I have a CRT318H where the intensity pin/gun/whatever isn't working so it only outputs 8 colors and I'd like to try fixing it.

September 15th, 2016, 12:59 PM
It seems to be impossible to get schematics for these old Monitors.

September 16th, 2016, 08:46 AM
Sadly, yes. And this one has so much going on inside. I can usually figure my way around monitors, but this one has a few boards that I'd really like to see a schematic of to figure out what they are doing.