Great stuff. I recently lifted some tracks under the lower RAM during a rushed repair of an Issue 3. Watching this video made me realised that people have screwed up their boards far more than mine, and there's always a way to get them working again. :D
14:40 - this is an example for a lower RAM module; upper RAM chips are 4 times bigger (256x256 array, with upper OR lower half active). Good to see another speccy brought back to life 😀
What a wonderful restoration, congrats! I wonder if it is better, for boards so damaged like this, to just recreate them with a modern service as PC way, and move all the good components to the new one.
BTW for patching stuff, enamelled wire is well worth having... especially for repairing the tracks where the memory was. The enamel will only melt where it is heated with the iron, so you can make really neat joints without worrying about the hassle of plastic insulation melting. I salvaged most of my stock from scrapped CRT's but you can buy it easily enough. I hate seeing burned flux like that.. almost certainly the result of using a cheap plug-in mains soldering iron that doesnt regulate its temperature. Temperature regulated irons are so cheap nowadays there is no excuse for not having one!
@@HappyLittleDiodes I use enamel wire too, and bend it to follow the line where the broken track was. Once it is confirmed working, the apply green nail polish on top of it, which sticks it well enough to the board (has to be really cleaned with IPA before) and also restores the look of the solder mask.
looking at the state that board was in at the beginning of the video i don't feel so bad about my ham-fisted attempt at fixing my issue 2 board - lets just say that i learned how easy those traces can lift, especially if you use a stupidly hot iron and a vicious mechanical solder pump ... still, i got it working in the end though!
Hard work that, especially with the removed traces. Just bought 3 Speccies and 2 c64s to add to my working stock. Hope they aren't that bad. What make and model of oscilloscope is that and do I really need one (I have a RAM chip tester for those chips and a multimeter) ?
@@HappyLittleDiodes I have to wonder is it better to harvest chips off these boards and put them on reproduction motherboards ? Seems a ULA died in one of the repairs…. Still impressive to see the repairs and the hard work !
it really does annoy me when people try to do work like this when they clearly do not have the experience needed. Practice first - on junk, or cheap kits.. not something valuable like a Spectrum!
Great stuff. I recently lifted some tracks under the lower RAM during a rushed repair of an Issue 3. Watching this video made me realised that people have screwed up their boards far more than mine, and there's always a way to get them working again. :D
What an incredible rescue! I always enjoy spectrum boards being resurrected from the brink of no hope, fantastic job! 👍🏻
Thanks!
14:40 - this is an example for a lower RAM module; upper RAM chips are 4 times bigger (256x256 array, with upper OR lower half active). Good to see another speccy brought back to life 😀
What a wonderful restoration, congrats! I wonder if it is better, for boards so damaged like this, to just recreate them with a modern service as PC way, and move all the good components to the new one.
BTW for patching stuff, enamelled wire is well worth having... especially for repairing the tracks where the memory was. The enamel will only melt where it is heated with the iron, so you can make really neat joints without worrying about the hassle of plastic insulation melting. I salvaged most of my stock from scrapped CRT's but you can buy it easily enough.
I hate seeing burned flux like that.. almost certainly the result of using a cheap plug-in mains soldering iron that doesnt regulate its temperature. Temperature regulated irons are so cheap nowadays there is no excuse for not having one!
I have some enamelled wire but I haven't actually used it yet!
@@HappyLittleDiodes Once you try it you'll never make patch wires without it again ;)
@@HappyLittleDiodes I use enamel wire too, and bend it to follow the line where the broken track was. Once it is confirmed working, the apply green nail polish on top of it, which sticks it well enough to the board (has to be really cleaned with IPA before) and also restores the look of the solder mask.
looking at the state that board was in at the beginning of the video i don't feel so bad about my ham-fisted attempt at fixing my issue 2 board - lets just say that i learned how easy those traces can lift, especially if you use a stupidly hot iron and a vicious mechanical solder pump ... still, i got it working in the end though!
That's what I like to hear!
Another great video, excellent work.
That really is a good picture, that just the 100uf, composite mod?
Yes that's right
Hard work that, especially with the removed traces.
Just bought 3 Speccies and 2 c64s to add to my working stock.
Hope they aren't that bad.
What make and model of oscilloscope is that and do I really need one (I have a RAM chip tester for those chips and a multimeter) ?
Holy sh....! Whoever done the previous "repair" shouldn't be allowed to touch a soldering iron (or blowtorch?) for life.
Thanks for your detailed explanations can I ask what is the model of microscope your using.
This was a simple handheld USB microscope from amazon, just a generic cheap one
@13:20 aren't you missing one of the capacitors for the -5/12v voltage circuit. Isn't there 4 on the right side?
Yes :) I was waiting for some new 4.7uF caps. C74 improves reliability but as we saw the spectrum still runs and voltages seemed OK
@@HappyLittleDiodes I have to wonder is it better to harvest chips off these boards and put them on reproduction motherboards ? Seems a ULA died in one of the repairs…. Still impressive to see the repairs and the hard work !
it really does annoy me when people try to do work like this when they clearly do not have the experience needed. Practice first - on junk, or cheap kits.. not something valuable like a Spectrum!
Intermission..