Brett's STE - Repair thread

Blogs & guides and tales of woo by forum members.
Post Reply
User avatar
stephen_usher
Posts: 5578
Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
Contact:

Re: Brett's STE - Repair thread

Post by stephen_usher »

Isn't the check for the external ROM about something like 4 instructions in from the beginning?
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Brett's STE - Repair thread

Post by exxos »

stephen_usher wrote: Sun Jan 16, 2022 6:30 pm Isn't the check for the external ROM about something like 4 instructions in from the beginning?
https://www.exxosforum.co.uk/forum/viewt ... 990#p77016
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10465
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Brett's STE - Repair thread

Post by rubber_jonnie »

Just to let folks know, this is still a work in progress, but as I am now over the main part of the soldering, I may not post on here as often, as it's now a case of double checking my work for connection errors and anything I've missed on both the top and bottom side of the PCB.

It will take me some time as my time in the evenings is about to get a little more limited due to being back at karate, but I will post anything that is of interest as soon as I have it :)
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
BrettRogersUK
Posts: 129
Joined: Wed Sep 15, 2021 12:48 am

Re: Brett's STE - Repair thread

Post by BrettRogersUK »

Great stuff, look forward to seeing progress. I used to do Karate back in the day. Both me and brother did. I didn't do it for very long but my brother carried on and really enjoys it.

I'm actually glad I sent you the board when I did because it would have just been calling out to me and tempting me to keep getting the board out and probably do a lot more damage than what was already done. So grateful for you offering to look at it.

Cheers,

Brett
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10465
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Brett's STE - Repair thread

Post by rubber_jonnie »

BrettRogersUK wrote: Thu Jan 20, 2022 2:45 pm Great stuff, look forward to seeing progress. I used to do Karate back in the day. Both me and brother did. I didn't do it for very long but my brother carried on and really enjoys it.

I'm actually glad I sent you the board when I did because it would have just been calling out to me and tempting me to keep getting the board out and probably do a lot more damage than what was already done. So grateful for you offering to look at it.

Cheers,

Brett
No worries Brett, I'll do what I can. I'm in my 14th year of karate now, and hoping to go for my 2nd Dan grade this year.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10465
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Brett's STE - Repair thread

Post by rubber_jonnie »

Spent some time today verifying my wiring again by buzzing it out. Having a schematic in Kicad where I can highlight traces is definitely a huge help here, rather than trying to follow Atari's musty old drawing!

I confirmed that VCC and GND were all good across both sockets, and all of the address lines are correctly wired as per the schematic. It did highlight a minor error on my part with 1 wire incorrectly placed, so I rectified that.

The final check is the data lines, and I think that is where the problem lies as comparing to my working machine, at least 1 data line isn't behaving the same.

More buzzing out to come!!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
User avatar
stephen_usher
Posts: 5578
Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
Contact:

Re: Brett's STE - Repair thread

Post by stephen_usher »

Bzzzzzzz!
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Brett's STE - Repair thread

Post by exxos »

Probably worth checking you have 10k etc pull up resistance on all the ROM and CPU pins.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10465
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Brett's STE - Repair thread

Post by rubber_jonnie »

exxos wrote: Sun Jan 23, 2022 12:12 am Probably worth checking you have 10k etc pull up resistance on all the ROM and CPU pins.
They look original, and funnily enough I haven't changed them in my own STE. But I can change them whilst I'm at it, but reluctant to change too much else until I am 100% sure I have all the wiring right.

Good call though.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Brett's STE - Repair thread

Post by exxos »

rubber_jonnie wrote: Sun Jan 23, 2022 12:14 am They look original, and funnily enough I haven't changed them in my own STE. But I can change them whilst I'm at it, but reluctant to change too much else until I am 100% sure I have all the wiring right.
I half recall bodge wires to resistor packs at one point ? I know you metered a lot out. But checking the pins actually have pull ups will check a lot of traces etc as well. The actual resistance *shouldn't* matter at this point..

Also not sure if you're pressing reset button during tests ? Would be typical to actually have fixed it and the reset circuit died...
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Post Reply

Return to “MEMBER BLOGS”