Brett's STE - Repair thread

[mikro]

Thanks @rubber_jonnie for the great writeup, I'm always quite disappointed by posts like "I fixed it, it was a missing wire!" without further details. The process is always great to observe, it gives me a lot of valuable information.

[rubber_jonnie]

You've done an exceptional job mate. I can't really put into words how excited I am to hear that the machine is actually working again.

I will be forever grateful to you for doing this. I can't wait to get it back and back in its case where it will stay from now on.

I see you've added the jumpers as well in place of the resistors. That was another one of things on my list to do. Like I say though, now when I get it back it can go in its case and be left alone. No way am I touching this or any other board again (well not without making sure I've got the proper tools to hand first and foremost). I think I'll leave this kind of job to the professionals in the future.

It kind of makes you wonder just looking at the size of that board, with the size of components rapidly shrinking and being surface mount components as well, just think how big the STE motherboard could be now days compared to that.

Kindest Regards and best wishes,

Brett

It might sound weird, but I do this sort of stuff for fun :)

As somebody who is not an electronic expert, being able to find and resolve problems using practical techniques and skills learned over time gives me a buzz, especially when it means I can revive machines like this.

Of course I do have an understanding of what various components do, and what 'scope traces should look like etc, and I have slowly improved my soldering (and other) skills over quite a long time.

But I have made my mistakes, similar to yours, and even with the right tools, things can go wrong, or at least be very difficult. For example, the 6850s have some pins that are particularly hard to desolder, even with a desolder gun, so then you have to employ other techniques, such as using hot air to soften the solder that didn't suck out, but of course hot air comes with it's own risks. It's a big balancing act between do no harm and do more harm!

As for STEs shrinking down if they were made today, look at the likes of the Mister and MiST FPGA machines, you have your answer right there.

I'll see what that FDD switch entails over the next few days, and will likely do it next week and then do a final wrap up. Once done I'll get it all packed ready for shipping and will let you know when to arrange collection :)

[rubber_jonnie]

Thanks @rubber_jonnie for the great writeup, I'm always quite disappointed by posts like "I fixed it, it was a missing wire!" without further details. The process is always great to observe, it gives me a lot of valuable information.

You're welcome, and it was always going to be the case it would have a write up for the very reasons you've mentioned.

Hopefully it goes some way to show that fixing these machines is quite a complex process, and that you need to have a lot of tools and knowledge at your disposal, and of course all of the people on this forum who have also made valuable contributions to the thread, it has been a great team effort.

[rubber_jonnie]

Ok, so I'm back from my parents now, so next up for Bretts STE is the floppy switch MOD to allow either the internal or external drive to be used as A:

I'll get on that this week hopefully.

Of interest, I looked at roughly how long it took to repair this machine, and it topped out at about 40 hours. Some of us discussed what we'd charge for repairs and it came out around £20 per hour, which would make for a repair bill of £800. You could probably buy 2 STEs for that.

So here's where it gets problematic. I like doing repairs, it gives me a buzz, probably more than using these machines, but I think charges like that would be very contentious IMHO.

This is one reason why I don't generally do repairs, and I have had several requests since doing this to look at other machines. It is hard to accept though as I seem to be quite good at it.

[PhilC]

@rubber_jonnie it's all about the fun value. When the fun stops ... stop.

[stephen_usher]

@rubber_jonnie its all about the fun value. When the fun stops ... stop.

I agree. It’s the puzzle solving. Having the pressure of the stuff not being your own would decrease the fun for me.

[exxos]

I hear'ya. I gave up quoting people to upgrade machines as even just £10 to install a kit.. Several kits, plus the cost of the kits could ramp to £200-£400. They would always go quiet. Then they try and fit themselves and trash the machine which then takes several times longer..

Builders tend to charge £200 a day minimum. Electronics is IMHO a more skilled job and more work. £25 a hour is peanuts for the sills involved. I've known IT people charge £2,000 a day!

OTOH for me, its like i sometimes diagnose peoples falcons for free ( still expect postage repaid) *IF* they have a problem like the guys did with my clock patch, it sparks my interest and it improves future kits as things have been learned . But dead falcons.. People must have deep pockets and patience. The last falcons I looked at I regret as they started to pester me and didn't listen to what I told them which caused more headaches and I ended up losing money over it all. Didn't even get a thank you. Just reasons I stopped doing such work.

IMHO do repairs which spark your own interest. I get people asking me to look at machines every couple of days. I tell 99% of people no! I just don't have time and with my RSI... Plus like you say, £800 to fix a £100 machine. Bonkers unless people have deep pockets. So IMHO £100 should be minimum for the work. It gives you something to buy more test gear etc

I'm not suggesting what you do or don't do its up to you of course. Just throwing out some thoughts as I've been through all this for 25+ years now.

[rubber_jonnie]

@rubber_jonnie it's all about the fun value. When the fun stops ... stop.

100%

[rubber_jonnie]

@rubber_jonnie its all about the fun value. When the fun stops ... stop.

I agree. It’s the puzzle solving. Having the pressure of the stuff not being your own would decrease the fun for me.

Yep, I totally get that too.

[rubber_jonnie]

I hear'ya. I gave up quoting people to upgrade machines as even just £10 to install a kit.. Several kits, plus the cost of the kits could ramp to £200-£400. They would always go quiet. Then they try and fit themselves and trash the machine which then takes several times longer..

Builders tend to charge £200 a day minimum. Electronics is IMHO a more skilled job and more work. £25 a hour is peanuts for the sills involved. I've known IT people charge £2,000 a day!

OTOH for me, its like i sometimes diagnose peoples falcons for free ( still expect postage repaid) *IF* they have a problem like the guys did with my clock patch, it sparks my interest and it improves future kits as things have been learned . But dead falcons.. People must have deep pockets and patience. The last falcons I looked at I regret as they started to pester me and didn't listen to what I told them which caused more headaches and I ended up losing money over it all. Didn't even get a thank you. Just reasons I stopped doing such work.

IMHO do repairs which spark your own interest. I get people asking me to look at machines every couple of days. I tell 99% of people no! I just don't have time and with my RSI... Plus like you say, £800 to fix a £100 machine. Bonkers unless people have deep pockets. So IMHO £100 should be minimum for the work. It gives you something to buy more test gear etc

I'm not suggesting what you do or don't do its up to you of course. Just throwing out some thoughts as I've been through all this for 25+ years now.

Yeah, a lot to take in from the overall experience. Right now doing regular repairs for others is just not possible, despite the enjoyment it brings, but I may well consider it down the line, but if I do there will definitely be conditions that need to be very well thought out.

We'll see....