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Re: Which 1040 STF is this?

Posted: Fri Mar 01, 2019 12:10 pm
by Maximilian
PM sent

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 1:49 am
by 32bitminus
Maximilian wrote: Thu Feb 28, 2019 11:46 pm Always nice to see someone taking the time to clean an old machine up.
I'm a bit of a ST noob but is this a 8 or 16Mhz 68000?
Also where are you located.
(if I may ask)
Thanks! Will post a few more beauty shots when I retrobrite the case and keys. 8Mhz I think.

I saw your PM will respond.

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 2:01 am
by 32bitminus
So, for the life of me took forever to get the solder out to do the composite sync mod, if I could have found my flux, would have probably helped... So after adding fresh solder and spending over an hour to get the board cleaned up, finally got all the components in. For the life of me I guess my tip was not big enough and the pad was acting as a sink, but could not get the solder out of the last hole for R51, it was on the larger ground pad, so I ending up cheating and doing a surface mount for that.

Had my iron at 626F and didnt want to go much higher. I manged to remove 1mm of circuit trace protector of a nearby trace, so off to the internet to get something to protect that from corrosion. That last connection was a bear.

Anyways got it all back together, installed my new ubeswitch, plug in the monitor I read was 15khz and nope, nada. Thinking great, maybe fried a component with too much heat or a cold joint and have to re-install. Tried a super old tube VGA monitor from 2000, nada.

Went through my 5 other 4:3 LCDs, nada.

So I thought, let me try the Westinghouse W33001 30" LCD I paid $1000 for back in 2003 or so, being the pack-rat I am, oldest LCD I have, only 720P and weighs like 60lbs.

Magic! Top and Bottom look cut of but we will see if that affects games, same with aspect ratio off too. Wow I would have died back in the day for 30" on the ST :)

That Late 90s gray plastic with silver speakers fits the Atari perfect! Thanks folks for all your help. Now to get the floppy back in after the cleaning and lube job, along with cleaning that shield up, replacing some missing floppy support brackets and going of the case and keyboard a bit more, I can then run that sysinfo.
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Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 4:11 am
by 32bitminus
Plugged in the Floppy and nothing. Pulled stepper was seized, move it by hand worked it free, lubed it a bit. Worked once and died. Noticed if I pushed the transport down it moved smoothly, so flipped it upside down and banged the stepper a bit to get it to move ever so slightly. On my 486 I can now format and write floppies that work with the ST and back. ST formated floppies I assume I can't read and is normal.

Here is the sysinfo:
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Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 11:40 am
by rubber_jonnie
I'd suggest that you might want to look at getting an upgrade to TOS, as 1.02 isn't great. I'd go for 1.04, which you can get here: https://www.exxosforum.co.uk/atari/store2/#0057

If you wanted to go for dual TOS, then there are options a little further down on that page.

As for the floppy drive, IMHO, unless you really must have a floppy drive for authenticity, you need to get a Gotek instead. You can buy them ready flashed with FlashFloppy off eBay these days, but if you want to do it yourself, I did a guide here: https://www.exxosforum.co.uk/forum/viewt ... oing+gotek

Just reading back in the thread, I run my iron at 370C, which is about 700F, and generally don't have any problems with the ST mainboards. The ground planes can be a bugger though.

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 1:05 pm
by Maximilian
What kind of soldering iron/station are you using?

Normally repairs will go pretty smooth with 380C, when using wick i also wick from the top (mostly C64), that cleans most of them up nicely.

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 1:30 pm
by rubber_jonnie
Maximilian wrote: Sat Mar 02, 2019 1:05 pm What kind of soldering iron/station are you using?

Normally repairs will go pretty smooth with 380C, when using wick i also wick from the top (mostly C64), that cleans most of them up nicely.
I'm sure you're aiming this at the orginal poster, but I'm just using this simple thermostatically controlled iron:
iron.jpg
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370/380C does seem to be the charm for ST boards in my experience, I also use wick, but I find I offten need to go top and bottom, though pulling the 68k seems fine from the bottom only oddly.

Size of the solder tip also seems to play a part in how hot you need to be.

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 2:47 pm
by Maximilian
rubber_jonnie wrote: Sat Mar 02, 2019 1:30 pm I'm sure you're aiming this at the orginal poster
Both actually,

Ah, I know that soldering station(or one of its predecessors), we used to use those in our electronics classes.

I'm a fan of the Weller Magnastat style of soldering irons, they are pretty stable with their temperature except for the larger ground plane desoldering jobs.

If a ground or VCC pin really wont budge I always:
1. Try to remove as much solder as I can from the top and the bottom using good solder braid and sometimes try again with fresh solder applied,
2. Add a little solder to the offending pin.
2. I unsnap all the other pins with a dental hook, and then I heat the offending pin while taking the chip out.

The above only gives me any grief if someone else had a go at it, mostly because they solder to long or use a temperature that is to high and the pads come off.
I soldered and desoldered a 68 pin 2mm DIP chip 4 times without any damage to the traces the other day.
(Socket wasn't working or so I thought, but it was the replacement chip that was a dud :cussing: )

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 3:22 pm
by rubber_jonnie
Maximilian wrote: Sat Mar 02, 2019 2:47 pm
If a ground or VCC pin really wont budge I always:
1. Try to remove as much solder as I can from the top and the bottom using good solder braid and sometimes try again with fresh solder applied,
2. Add a little solder to the offending pin.
2. I unsnap all the other pins with a dental hook, and then I heat the offending pin while taking the chip out.

The above only gives me any grief if someone else had a go at it, mostly because they solder to long or use a temperature that is to high and the pads come off.
Completely agree with the above, ST boards are quite hardy, but overheating when desoldering can easily cause pad lifting.

I tend to use fluxed solder wick, but always have some liquid flux to hand just in case. I also have a de-solder iron, which is essentially an iron with a de-solder sucker built in, wich has got me out of the odd spot or two. I'd really like a Hakko desolder sucker, but they are just too pricey.

As well as adding solder, which to some may seem counter intuitive (It really isn't as you clearly understand :D ), I also try to make sure I don't keep heat in an area for too long, and if I think I am, I move to another pin as far away as possible from that area.

I have tried using hot air to desolder on an ST mainboard that I was recovering parts from for another project, but it was only really useful for the sockets. The PCB material really didn't like heat at all, because you could clearly see it delaminating.

As it was a dead board for parts recovery only, I wasn't too worried, but I would advise against it on a working board just to be on the safe side.

Re: Which 1040 STF is this?

Posted: Sat Mar 02, 2019 4:16 pm
by Maximilian
I've got one of those desoldering stations gathering dust in the corner, hate the thing as it tends to damage the pcb, maybe I need to practice some more or get another desolderingtip.

As a kid I always used a paint stripper to get loads of parts of boards (outside of the house ofcourse), heat and then give it a little tap on the side of the table.
And yes, the boards were nice and toasty afterwards.

But were getting a bit Off Topic..