Looking for Tektronix 4051 or 4052 Display Board

[Randy Dawson]

Hi Monty,


My 4051, which I have had for a couple of years now, has failed with a display problem very similar to yours, likely a power supply issue.


The characters all look funny, but I am able to type in a 10 PRINT "HELLO" 20 GOTO 10 and it fills the screen, so at least the processor is running.


I will open it up in the coming days.  I will take pictures and scope shots, and let you know what I find.


Good luck, fellow 405x owner!


Randy


________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Monty McGraw via cctalk <cctalk at classiccmp.org>
Sent: Tuesday, July 3, 2018 2:25 PM
To: Pete Lancashire; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Looking for Tektronix 4051 or 4052 Display Board

Pete,

Thanks for checking on the display board.

Are any of the other boards, power supplies or keyboards left in the 4051
or 4052?

Monty

On Tue, Jul 3, 2018 at 4:19 PM, Pete Lancashire via cctalk <
cctalk at classiccmp.org> wrote:

> ---------- Forwarded message ---------
> From: Pete Lancashire <pete at petelancashire.com>
> Date: Tue, Jul 3, 2018, 2:18 PM
> Subject: Re: Looking for Tektronix 4051 or 4052 Display Board
> To: Monty McGraw <mmcgraw74 at gmail.com>
>
>
> Yeah the two display boards went to Europe.
>
> If anybody needs three perfectly good 11 inch CRTs, deflection yolks
> excetera come to Portland Oregon and they're yours or have somebody pick
> them up for you they're in the scrap pile and scrap is going in about a
> month. Each CRT contains about $35 worth of gold.
>
> On Tue, Jul 3, 2018, 2:12 PM Monty McGraw <mmcgraw74 at gmail.com> wrote:
>
> > Pete,
> >
> > I'm in Texas near Houston.
> >
> > The Display Board is the vertical board to the left of the CRT.  It has
> > several cables at the bottom to pin headers and the cable to the neck of
> > the CRT.
> > It also has connectors to the power transistors that simply unplug when
> > you remove the Display Board.
> >
> > Here is a picture of a display board:
> > https://drive.google.com/file/d/0Bxd4qJinVzkNOFZacFZSYVJwaHc/
[https://lh4.googleusercontent.com/GizYrL4sWJr7c9n5zFCwd8m1UP22bKXbcwOpG7s44ZLsQHpKBJ_50g=w1200-h630-p]<https://drive.google.com/file/d/0Bxd4qJinVzkNOFZacFZSYVJwaHc/>

GAS6800A_CRT2.JPG<https://drive.google.com/file/d/0Bxd4qJinVzkNOFZacFZSYVJwaHc/>
drive.google.com


> view?usp=sharing
> >
> > Monty
> >
> > On Tue, Jul 3, 2018 at 4:01 PM, Pete Lancashire <pete at petelancashire.com
> >
> > wrote:
> >
> >> Is 206 Washington ? I have the remains of a 4051 4052 and 4010 terminal
> >> sitting outside in the scrap pile. Parts have gone to Europe but they're
> >> still pieces left over
> >>
> >>
> >> They were about 25 miles west of Portland Oregon.
> >>
> >>
> >>
> >> On Tue, Jul 3, 2018, 1:35 PM Ian Finder via cctalk <
> cctalk at classiccmp.org>
> >> wrote:
> >>
> >>> These systems are rare enough that it's probably worth fixing instead
> of
> >>> treating the board as a simple FRU. There are schematics on bitsavers
> for
> >>> that board, and they are complete.
> >>>
> >>> On Tue, Jul 3, 2018 at 1:21 PM, Monty McGraw via cctalk <
> >>> cctalk at classiccmp.org> wrote:
> >>>
> >>> > I've been repairing my Tektronix 4052.
> >>> >
> >>> > I've got the digital logic working - but the text and graphics are
> >>> messed
> >>> > up.
> >>> >
> >>> > I posted photos of the screens in my Tektronix 4052 troubleshooting
> >>> thread
> >>> > on vcfed.
> >>> >
> >>> > With a scope on the final X amplifier stage - it is oscillating - so
> I
> >>> see
> >>> > weird horizontal strokes instead of dots for text.  I know from the
> >>> service
> >>> > manual that this circuit includes a feedback loop, and with the scope
> >>> I see
> >>> > oscillation all around the loop - so I haven't found the source.
> >>> >
> >>> > Does anyone have a spare Tektronix 4052 (or 4051) Display Board that
> I
> >>> > could buy?
> >>> >
> >>> > Thanks,
> >>> > Monty
> >>> >
> >>>
> >>>
> >>>
> >>> --
> >>>    Ian Finder
> >>>    (206) 395-MIPS
> >>>    ian.finder at gmail.com
> >>>
> >>>
> >
>