Welcome, Guest. Please login or register.

Author Topic: Amiga 1070 repairs?  (Read 695 times)

Description:

0 Members and 1 Guest are viewing this topic.

Offline RobertBTopic starter

  • VIP / Donor - Lifetime Member
  • Hero Member
  • *****
  • Join Date: Jun 2005
  • Posts: 1833
  • Thanked: 23 times
    • Show only replies by RobertB
    • http://www.dickestel.com/fcug.htm
Amiga 1070 repairs?
« on: September 16, 2017, 05:12:24 AM »
Hi, everybody,

Ray Carlsen has my Amiga 1070 in for repairs, but he can't get very far without schematics.  Can anyone point us to some schematics?

Writing from Bensheim, Germany,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm
 

Offline Amiwest

  • S.A.C.C.
  • Full Member
  • *
  • Join Date: Apr 2009
  • Posts: 104
    • Show only replies by Amiwest
    • http://www.sacc.org
Re: Amiga 1070 repairs?
« Reply #1 on: September 17, 2017, 05:11:04 AM »
 

Offline RobertBTopic starter

  • VIP / Donor - Lifetime Member
  • Hero Member
  • *****
  • Join Date: Jun 2005
  • Posts: 1833
  • Thanked: 23 times
    • Show only replies by RobertB
    • http://www.dickestel.com/fcug.htm
Re: Amiga 1070 repairs?
« Reply #2 on: September 17, 2017, 06:12:09 PM »
Bill, unfortunately the Amiga 1070 RGB monitor is nothing like the composite/s-video 1701/1702.

Still in Bensheim,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm
 

Offline papa_november

  • Newbie
  • *
  • Join Date: May 2009
  • Posts: 16
    • Show only replies by papa_november
Re: Amiga 1070 repairs?
« Reply #3 on: October 02, 2017, 06:33:32 AM »
If it helps (it probably won't) the monitor was built by JVC and may have been sold under a different badge, much like how Phillips produced dozens and dozens of variants of what we know as the Commodore 1084.

The monitor that Ray is looking at may not have been sold as a Commodore 1070 (it had a DIN-8 connector before I messed with it), but there's no way to know for sure as all identifying labels were long gone by the time I got it.

JVC's model number is allegedly CM20311-005, but this does not return anything even vaguely meaningful in internet search results. The only entity that would have schematics for this monitor is JVC and it's not known how well they retain historical documents of this nature.

The monitor's symptoms were... odd. The tube was getting power and lighted up but no input signal showed up, ever. I probed and poked as much as I dared and the 5V supply is low. The monitor's power supply is in a separate section and of course the outputs aren't marked or anything helpful like that. Maybe a recap could cure it but a blind recap of this monitor would be quite and undertaking and not a single cap even remotely looks or smells like it is leaking.
 

Offline RobertBTopic starter

  • VIP / Donor - Lifetime Member
  • Hero Member
  • *****
  • Join Date: Jun 2005
  • Posts: 1833
  • Thanked: 23 times
    • Show only replies by RobertB
    • http://www.dickestel.com/fcug.htm
Re: Amiga 1070 repairs?
« Reply #4 on: October 02, 2017, 01:20:28 PM »
Ray wants to return it back to its original RGB connection.  Other than that, he is trying to get it working.

Writing from Prague, the Czech Republic,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm
 

Offline papa_november

  • Newbie
  • *
  • Join Date: May 2009
  • Posts: 16
    • Show only replies by papa_november
Re: Amiga 1070 repairs?
« Reply #5 on: October 03, 2017, 04:30:34 AM »
It's sort of built like an arcade monitor on the inside, though the isolation transformer isn't separate from the main board but is somewhere inside the power supply. The I/O panel on the back runs to a connector on the main PCB that sort of resembles those seen on Wells-Gardner monitor chassis. Since the back plate connector wasn't a Commodore original in the first place I thought "what the hell" and made it SCART so I could easily plug in not only Amigas but any other RGB-capable system as well. Too bad the rest of the monitor didn't work so I could see if my messy hack worked or not.

There's curiously little RF shielding (there may be a spray-on coating on the inside of the plastic serving that purpose like with some of the Apple machines). I'm guessing Commodore went over to what we now know as the 1080 for cost reasons.

Another thought: for some reason the monitor had a (crude) Atari case sticker on it when I found it. I just chalked that up to whoever had it last probably being an Atari ST owner. JVC did make one version of the SC1224 monitor that was sold for the Atari ST. I wonder if the innards are at all similar; I bet they share the same flyback and tube at the very least.