I’m still not used to modem oscilloscopes. The new ones crack me up how thin they are. My dad was like you a tech and had all the gear so I grew up with the big mamma jammas!
Yeah, sometimes those are a b**** but I thought for you double check all the capacitor replacements that have been done to make sure they put them in the correct polarity and then lift the VCC from the CPU to keep it from getting hot and then start checking voltages throughout the rest of the board you got this Chris. You're one of the best tech out there for this kind of work
That 1200 is going to take a lot of work. With the board bowed and 4 other hands in it... Lots of potential problems come to mind and who knows what the original problem was before it had been repaired unsuccessfully 4 times! Someone is going to have to scope it and try to find what looks like could be multiple problems after botched repair attempts. I get these bastards occasionally and I throw them on a "when I get around to it" shelf. You do this for free and have "Freepairs" piling so it only makes sense that you should move on to another machine after already putting a good deal of time and money into this one. You still gave it a hell of an attempt Doc! I think this video could be informative and helpful to those who are shopping for an Amiga as this video demonstrates how much time and money goes into repairing these machines and how much it might take to repair one you purchase off of "E booger". P.S. Analogic can blow! I've spent nearly $2k in the last year on orders from them at rediculas prices and they have horrible support so I concure with your pronunciation lol! Best Regards
Nothing like a stack of parts boards from the period! I hunted high and low for an SMD version of the 74F139 to fix a 600. Whaddya know I have some old Motorola automation system whatever boards (68040 baby!) and under the CPU found one of the chips I needed to bring that 600 back to life for no money :-)
As a computer tech, the board may be good for parts. You did all base troubleshooting on the Amiga 1200. The board have look by four other people for repair.😲
Not having the history is a PITA. Seems to me there are not enough wobble pops to cover up the frustration of working on that board. My eyes are so bad that having a stereoscopic microscope turned out to be a great investment although it took a while to get used to soldering with it, but it comes in very handy for PCB Inspection. I only work on my own stuff these days except when at work and even then, I have to bring boards home to work on them from time to time which is where I can concentrate on the issues at hand without people bothering me for other issues.
3:21 wondering why the bodge wire on that photo is soldered to the 4th pin in that row of XJ2, instead to the 1st, like the board you have (and at my Rev 1D.1). But I doubt that this would make a big difference to the major problems you have/had with the board. 🤔
I found all sorts of added parts, glass, resistors where they shouldn’t be ceramic capacitors where they shouldn’t be. I don’t know what’s up with this thing.
internal damage to layers 2 and 3 bonded. replaced everything, and crystal too. gals, roms, cpu grounded internally somewhere. so shes a parts board now.
That is not what I do it would take me too much time and Holt production on videos for at least six months plus you don’t know if you’re transferring junk parts to something new, considering the cost of replacement parts that is beyond my scope
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I’m still not used to modem oscilloscopes. The new ones crack me up how thin they are. My dad was like you a tech and had all the gear so I grew up with the big mamma jammas!
The chip log looked like the Plessey Logo. It was a company that did defence work in the UK and was bought by BAE Systems in the late 90’s
Yeah, sometimes those are a b**** but I thought for you double check all the capacitor replacements that have been done to make sure they put them in the correct polarity and then lift the VCC from the CPU to keep it from getting hot and then start checking voltages throughout the rest of the board you got this Chris. You're one of the best tech out there for this kind of work
That 1200 is going to take a lot of work. With the board bowed and 4 other hands in it... Lots of potential problems come to mind and who knows what the original problem was before it had been repaired unsuccessfully 4 times! Someone is going to have to scope it and try to find what looks like could be multiple problems after botched repair attempts. I get these bastards occasionally and I throw them on a "when I get around to it" shelf. You do this for free and have "Freepairs" piling so it only makes sense that you should move on to another machine after already putting a good deal of time and money into this one. You still gave it a hell of an attempt Doc! I think this video could be informative and helpful to those who are shopping for an Amiga as this video demonstrates how much time and money goes into repairing these machines and how much it might take to repair one you purchase off of "E booger". P.S. Analogic can blow! I've spent nearly $2k in the last year on orders from them at rediculas prices and they have horrible support so I concure with your pronunciation lol! Best Regards
Chris you did all you can to save this A1200. 😢😢😢
Nothing like a stack of parts boards from the period! I hunted high and low for an SMD version of the 74F139 to fix a 600. Whaddya know I have some old Motorola automation system whatever boards (68040 baby!) and under the CPU found one of the chips I needed to bring that 600 back to life for no money :-)
Super Video but for example on the weakbit Video you can see more exactly what and how to solder 😊
What?
@@ChrisEdwardsRestoration the soldering process is not so good viewable in your video. The camera is far away from your doing and soldering.
Yea maybe one day I will have the advanced cameras that I can get close up. I try best I can I’m sorry I can always shoot every single thing.
but In my mind your Videos are cool!
One thing to try is to check for shorted caps
It’s likely a internally shorted cpu chip possibly due to reverse polarity on the power supply
Replaced it and still dead
You can run an A1200 without the on-board CPU, I removed mine to give myself an extra 0.5mm to fit in a clock port expander 😂
As a computer tech, the board may be good for parts. You did all base troubleshooting on the Amiga 1200. The board have look by four other people for repair.😲
You win some, you lose some. It's knowing when to stop that's the hardest decision to make.
Not having the history is a PITA. Seems to me there are not enough wobble pops to cover up the frustration of working on that board. My eyes are so bad that having a stereoscopic microscope turned out to be a great investment although it took a while to get used to soldering with it, but it comes in very handy for PCB Inspection. I only work on my own stuff these days except when at work and even then, I have to bring boards home to work on them from time to time which is where I can concentrate on the issues at hand without people bothering me for other issues.
I hope Alex told you to keep the beer money. You dropped real cash in trying to get it fixed.
He did
3:21 wondering why the bodge wire on that photo is soldered to the 4th pin in that row of XJ2, instead to the 1st, like the board you have (and at my Rev 1D.1). But I doubt that this would make a big difference to the major problems you have/had with the board. 🤔
I found all sorts of added parts, glass, resistors where they shouldn’t be ceramic capacitors where they shouldn’t be. I don’t know what’s up with this thing.
this one's for spare parts
Too bad..
Maybe somebody can take the time to transfer the custom chips to give life to another board.
yeah someone else.
i dont do that. mr hertell does that.
Amtech flux works well but man it's sticky!
Indeed, it flows like butter, but when it hardens up it is like molasses in January
I've just realised who the person on your channel logo looks like! 🤔 He looks like Kim Jong Un! 😅
Its me on my poster!!
@@ChrisEdwardsRestoration I shouldn't have said anything. 😓
You can't win em all Chris.
Sorry after all your time spent on this lemon.
"Never stop thrusting"
-Elon musk
Bad crystal?
internal damage to layers 2 and 3 bonded. replaced everything, and crystal too. gals, roms, cpu grounded internally somewhere. so shes a parts board now.
Israel or Uranus I don't know 🤣
A Doctor can not save all Lives🤕 Never give up 👍🏻
buy a remake board and transfer parts
That is not what I do it would take me too much time and Holt production on videos for at least six months plus you don’t know if you’re transferring junk parts to something new, considering the cost of replacement parts that is beyond my scope
Without knowing the exact problem, you could just end up with the same thing.
Disappointing, but you cant save them all.