Repairing a Stacy

Troubles with your machine? Just want to speak about the latest improvements? This is the place!

Moderators: Mug UK, Zorro 2, spiny, Greenious, Moderator Team

joska
Hardware Guru
Hardware Guru
Posts: 4608
Joined: Tue Oct 30, 2007 2:55 pm
Location: Florø, Norway
Contact:

Re: Repairing a Stacy

Post by joska »

I clocked it at 12MHz, which worked fine except that the LCD got a bit dim. IIRC everything except shifter video was working correctly - floppy was working, YM sounding correctly, keyboard was working, ACSI was working (but not any faster, maybe due to the ancient 40Mb drive I was using). But I damaged the motherboard when I installed an AdSpeed 16 so I never finished my experiments.
Jo Even

VanillaMiNT - Firebee - Falcon060 - Milan060 - Falcon040 - MIST - Mega ST - STM - STE - Amiga 600 - Sharp MZ700 - MSX - Amstrad CPC - C64

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

joska wrote:I clocked it at 12MHz, which worked fine except that the LCD got a bit dim. IIRC everything except shifter video was working correctly - floppy was working, YM sounding correctly, keyboard was working, ACSI was working (but not any faster, maybe due to the ancient 40Mb drive I was using). But I damaged the motherboard when I installed an AdSpeed 16 so I never finished my experiments.
Ah, sounds promising. Was the damge through overclocking or something else?
Image

joska
Hardware Guru
Hardware Guru
Posts: 4608
Joined: Tue Oct 30, 2007 2:55 pm
Location: Florø, Norway
Contact:

Re: Repairing a Stacy

Post by joska »

The damage was entirely done by me and my (lack of) soldering skills :D
Jo Even

VanillaMiNT - Firebee - Falcon060 - Milan060 - Falcon040 - MIST - Mega ST - STM - STE - Amiga 600 - Sharp MZ700 - MSX - Amstrad CPC - C64

User avatar
AndresPlaza
Retro freak
Retro freak
Posts: 13
Joined: Mon Apr 29, 2019 2:30 pm
Location: Boston, MA, USA
Contact:

Re: Repairing a Stacy

Post by AndresPlaza »

Gaiyan wrote: It's too big, it gets in the way of any serious upgrade, it's too weak and finicky. Also unreliable in my experience. On one unit I've changed all caps and transistors and it keeps shutting down after a bit of use. Also the voltages drift and need constant adjusting.

But main reason is the size and location. I'd do this even if worked perfectly.
Why did you decide to go for the "Original/Big box adapter" instead of the "picoPSU adaptor"? The idea of having the picoPSU horizontally seems attractive, to fit it inside the Stacy case.

Andres.

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

AndresPlaza wrote:
Gaiyan wrote: It's too big, it gets in the way of any serious upgrade, it's too weak and finicky. Also unreliable in my experience. On one unit I've changed all caps and transistors and it keeps shutting down after a bit of use. Also the voltages drift and need constant adjusting.

But main reason is the size and location. I'd do this even if worked perfectly.
Why did you decide to go for the "Original/Big box adapter" instead of the "picoPSU adaptor"? The idea of having the picoPSU horizontally seems attractive, to fit it inside the Stacy case.

Andres.
Oh, right. I had bought it for my TT for the -5V, but it turned out to be so handy for troubleshooting STs that I left it out.
Image

User avatar
AndresPlaza
Retro freak
Retro freak
Posts: 13
Joined: Mon Apr 29, 2019 2:30 pm
Location: Boston, MA, USA
Contact:

Re: Repairing a Stacy

Post by AndresPlaza »

Gaiyan wrote: Oh, right. I had bought it for my TT for the -5V, but it turned out to be so handy for troubleshooting STs that I left it out.
Ah! Then I will give the picoPSU adaptor a try. Thanks!

cyberish
Obsessive compulsive Atari behavior
Obsessive compulsive Atari behavior
Posts: 101
Joined: Mon Dec 17, 2007 9:18 pm

Re: Repairing a Stacy

Post by cyberish »

Hi Andres
thx for sharing! Maybe you want to correct the link in your first post about your first Stacy blog ? : https://vintagecomputers.code.blog/2020 ... cy-part-1/

joska
Hardware Guru
Hardware Guru
Posts: 4608
Joined: Tue Oct 30, 2007 2:55 pm
Location: Florø, Norway
Contact:

Re: Repairing a Stacy

Post by joska »

Gaiyan wrote:Note that as the STacy screen dims, the flat background light gets a little darker as well. This creates a dark background on which dark letters of the LCD must be read.
Just came across this. Please note that the LCD panel itself does not get dimmer over the years. It's the EL backlight itself that deteriorates. If you get to the point where you have to install a reflective background you can just remove the EL-sheet, it no longer has any use.

This is a good solution BTW, as long as you can use external lighting (as you point out). Very simple and costs nothing. A different solution is as mentioned before - convert to LED lighting. Take out the diffuser from a broken LCD screen, cut it to size, slide it in behind the LCD panel instead of the EL-sheet. And then the slightly tricky part, install LEDs to do the actual lighting. If I ever finish my Stacy rebuild/repair I'll document this process.
Jo Even

VanillaMiNT - Firebee - Falcon060 - Milan060 - Falcon040 - MIST - Mega ST - STM - STE - Amiga 600 - Sharp MZ700 - MSX - Amstrad CPC - C64

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

AndresPlaza wrote:
Gaiyan wrote: Oh, right. I had bought it for my TT for the -5V, but it turned out to be so handy for troubleshooting STs that I left it out.
Ah! Then I will give the picoPSU adaptor a try. Thanks!
Turns out this -20V is more complex than what I expected from the previous solution. I was able to get -20V but isolated, not to common ground. ST Book schematics show a MAX634 being used for the -20V but it's a bit complex as well. So it's absurd to replace something complex with another complex, except you have to design and test it all over.

So it just might be that the best solution is to fully re-condition the existing PSU and go with it.
joska wrote:
Gaiyan wrote:Note that as the STacy screen dims, the flat background light gets a little darker as well. This creates a dark background on which dark letters of the LCD must be read.
Just came across this. Please note that the LCD panel itself does not get dimmer over the years. It's the EL backlight itself that deteriorates. If you get to the point where you have to install a reflective background you can just remove the EL-sheet, it no longer has any use.

This is a good solution BTW, as long as you can use external lighting (as you point out). Very simple and costs nothing. A different solution is as mentioned before - convert to LED lighting. Take out the diffuser from a broken LCD screen, cut it to size, slide it in behind the LCD panel instead of the EL-sheet. And then the slightly tricky part, install LEDs to do the actual lighting. If I ever finish my Stacy rebuild/repair I'll document this process.
Those were not my words, but from the DOIT_ST archive. But yes, the LCD itself is perfect. I'll try to source a broken laptop or few myself to try the backlight.
Image

User avatar
AndresPlaza
Retro freak
Retro freak
Posts: 13
Joined: Mon Apr 29, 2019 2:30 pm
Location: Boston, MA, USA
Contact:

Re: Repairing a Stacy

Post by AndresPlaza »

cyberish wrote:Hi Andres
thx for sharing! Maybe you want to correct the link in your first post about your first Stacy blog ? : https://vintagecomputers.code.blog/2020 ... cy-part-1/
Thank you very much for pointing out! Unfortunately, I cannot find an edit button for posts... Am I missing something?

Andres.

cyberish
Obsessive compulsive Atari behavior
Obsessive compulsive Atari behavior
Posts: 101
Joined: Mon Dec 17, 2007 9:18 pm

Re: Repairing a Stacy

Post by cyberish »

hmm, I think you have just to click on your first post right side pencil icon which shows up when you're logged in here.

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

AndresPlaza wrote:
cyberish wrote:Hi Andres
thx for sharing! Maybe you want to correct the link in your first post about your first Stacy blog ? : https://vintagecomputers.code.blog/2020 ... cy-part-1/
Thank you very much for pointing out! Unfortunately, I cannot find an edit button for posts... Am I missing something?

Andres.
Editing is not available anymore http://www.atari-forum.com/viewtopic.ph ... 63#p383294
Image

cyberish
Obsessive compulsive Atari behavior
Obsessive compulsive Atari behavior
Posts: 101
Joined: Mon Dec 17, 2007 9:18 pm

Re: Repairing a Stacy

Post by cyberish »

Seriously... interesting that I still have the pencil and edit option showing up... If it's the case of no editing possible anymore it's odd imo. - Sometimes we write something we want or must change later on... (what's in the brackets here , I'm writing in "reediting modus"... - so yes it works at least for me... ) 2nd reedit: sorry for going slightly offtopic.

Back on track: Did you try your 2nd new LCD panel ? - I've a Stacy 2 waiting to do "all of this"...

User avatar
AndresPlaza
Retro freak
Retro freak
Posts: 13
Joined: Mon Apr 29, 2019 2:30 pm
Location: Boston, MA, USA
Contact:

Re: Repairing a Stacy

Post by AndresPlaza »

Gaiyan wrote: So it just might be that the best solution is to fully re-condition the existing PSU and go with it.
Except, of course, if you want to install an accelerator.

How about something like this:

https://www.digikey.com/product-detail/ ... ND/6588566

in parallel to the picoPSU? Of course, and a beefier power supply.

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

K, changed the voltage trimmers on one DC/DC. Soooo much better now. Will change the other psu as well.
Image

User avatar
DarkLord
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 4440
Joined: Mon Aug 16, 2004 12:06 pm
Location: Prestonsburg, KY - USA
Contact:

Re: Repairing a Stacy

Post by DarkLord »

AndresPlaza wrote:
Except, of course, if you want to install an accelerator.

in parallel to the picoPSU? Of course, and a beefier power supply.
Umm, I'm using the Pak 68/3 board in my STacy - I rewired the original,
internal P/S board and moved it into the battery compartment. A bit
tedious, to say the least but "do-able". :)

PS I had originally went with a Pico P/S but couldn't get it to power the
stock screen because of that annoying -20v requirement. :(
Welcome To DarkForce! http://www.darkforce.org "The Fuji Lives.!"
Atari SW/HW based BBS - Telnet:darkforce-bbs.dyndns.org 520

User avatar
Gaiyan
Hardware Guru
Hardware Guru
Posts: 492
Joined: Tue Jun 29, 2004 3:39 pm
Contact:

Re: Repairing a Stacy

Post by Gaiyan »

Image

Post Reply

Return to “Hardware”