Questions from noob about new motherboard

[Trip3nite]

Hello
A friends father found an old Atari ST 1040f in his attic and gave it to me.
Tried turning it on but the screen starts glithing with a bunch of bomb icons all over the place until it freezes shortly after.
No idea whats wrong with it...
I was thinking about getting one of these new motherboards instead of buying an old one, as I read old ones are starting to fail frequently nowadays.
I see that i need to source components from an old motherboard to use on a H5 board, but probably something on my board has failed, so i suspect there will be troubles when installing those components on a new motherboard.
Is there any way that i can :
-break the H5 motherboard by trying it with the components i have on my failing board?
- find out which part on my motherboard is broken?

I could just buy each component the H5 needs new or second hand, but this seems really stupid as i assume most components on my board still work.

Any help would be appreciated
Thanks!

[Ghostie]

One of the first things to always check with one of these old machines is the voltages coming from the power supply.
Once you know you have clean power then you can troubleshoot the rest of the machine.

Also look for any obvious damage or corrosion on the board.

Check and reseat any socketed chips.

[Ghostie]

The capacitors on most old power supplies will generally need replacing.
Alternatively Exxos sells new power supplies on the store item 0030
For the future before powering on old equipment it is best to verify the PSU is functioning properly as it is possible for them to put out damaging voltages to components ^-^

[Steve]

1) the motherboard might be very easy to fix. Usually it's as simple as re-seating all socketed chips, both PLCC and DIP, don't forget the ROMS. Clean the sockets with cleaning solvent if you have some.

2) in regards to buying all the bits you need for a H5. You can buy most bits, but you'll need the custom chips like shifter/glue etc which usually come from donors. Sometimes you can find them online. I doubt the chips on your board have failed, that would be very rare.

[Trip3nite]

Allright I got some experience with fixing electronics before, but not as much to not still be considered a noob.
I've just followed some guides to fix laptops/consoles before, and usually it was just some parts that needed replacement/resoldering.
So basically thats my knowledge when it comes to this kind of stuff.
My roommate has some more experience as he used to repair phones a lot.
He gave me this tool to take out chips, so I reseated them, but everything was still the same when i turned it back on.
My roommate also checked the psu with his multimeter and he said its outputs are acceptable and actually closer to what's promised than most measurements of Atari ST psu's he could find online, so it shouldn't be the problem either...
I wanna use this for cubase, already bought a dongle clone too, but a friend of mine has an ST in his retro gaming console collection, which has a new exxos psu.
I could maybe go to him and try his psu in my system, but yeah I'd be suprised if it was the psu...
My roommate says he'd be happy to help me fix it, but he just has soldering stuff and a multimeter, and he said he doubts this is enough to figure out whats wrong, and possibly an oscilloscope is needed to check individual chips, which is something he also has almost no experience with...

No idea what's broken, but my guess is that most (if not all but 1) components on my board still work fine, so i'd love to just use them and buy a replacement for whatever is broken...
I browsed online and I see that I can find systems without monitor for about 75-100€
I'm afraid I can't get my own board checked + buy replacement components for less than that, but abandoning this one feels like such a waste...

[Ghostie]

Would you be able to post a picture of the messed up output? Could be of help.

[exxos]

If you are going to fix the ST then you are probably going to need a diagnostic cart as it is probably a RAM fault you have.

[Trip3nite]

Yeah just went out with some friends so can't do it now, but I'll post a pic tomorrow
I could turn on the computer and the desktop would even load sometimes, but then glitches on the screen start appearing with a bunch of bomb icons and then everything freezes (can still move mouse for a few seconds when it starts glitching before it freezes)
I tried turning it on a few times yesterday, this morning, and after i reseated chips
Every time it seems that after a few tries, it starts glitching sooner, sometimes starting up to glitches straight away, but then after not being powered on for a while, it takes a bit longer for things to start glitching again after turning on the machine.
Idk if that can help already, otherwise tomorrow i can post some pictures.

[Trip3nite]

If you are going to fix the ST then you are probably going to need a diagnostic cart as it is probably a RAM fault you have.

Ahh i see it will already cost me 45€ cost+shipping to get one of those
And then I also need to buy and replace whatever is broken...
If I'm lucky I should even be able to find a new ST for that money (was suprised these things are still so cheap after retro gaming popularity made prices explode)
If it wouldn't cost me more to get this fixed than just buying a new one, I would though, as I really don't like throwing this one out
But how sure can I be that a diagnostic cart will find what the problem is?

[exxos]

If it wouldn't cost me more to get this fixed than just buying a new one, I would though, as I really don't like throwing this one out

Understandable of course. It could be more cost-effective to get another ST then at least you can swap parts around the desk they are good or not. Assuming another ST worked properly .

But how sure can I be that a diagnostic cart will find what the problem is?

The diagnostic cart can only do so much. But it will be rather difficult to diagnose problems on the machine without it.

It sounds like your system is booting. so I would assume you could at least test RAM properly. But it is basically the only way of diagnosing machines other than swapping parts around the second machine. But even that is not a surefire way of diagnosing problems either.

But in my experience the main chips don't generally fail. It is normally the RAM which dies first, aside from the PSU that is. Because if your power supply does not work under load, then things on the computer are not going to work properly. This is why the mandatory fixes exist. You have to start at the start of the repair list and at least have a properly working power supply.

Once you know your machine has good power then you need some way of diagnosing the RAM. Which if the machine is not running then the diagnostic cartridge is your only option.

Unfortunately these machines are 30-40 years old now. Pretty much all of them need some sort of repair or servicing or are just completely dead for one reason or another. It is always better to get a couple of machines and hope one of them actually works. And you can swap parts and they will help diagnose some problems that way.

My roommate also checked the psu with his multimeter and he said its outputs are acceptable and actually closer to what's promised than most measurements of Atari ST psu's he could find online, so it shouldn't be the problem either...

Simply checking the voltage isn't enough. You didn't mention if this was under load or not. To check a power supply properly needs to be under load and checked with a oscilloscope to see what the voltage regulation is actually like.

I have a huge page talking about power supplies and problems here https://exxosforum.co.uk/atari/last/psu/index.htm