Amiga 600 repair - Boot problem
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- Опубліковано 15 вер 2013
- It's time for a June Bug repair. At power on, this motherboard first passed some of the self-tests only to then die to a black screen, which made it never reach the kickstart screen.
After I managed to get it to boot up again, I noticed there was an audio problem with it as well. I thought I would be done working on the board after repairing what caused this audio problem. But nope, the motherboard was stubborn and didn't want to cooperate with me on that point. Instead, it gave me a second audio related problem that I had to deal with...
As always, feel free to post comments and questions regarding the repair in the comment section. - Наука та технологія
King of Amiga Repair! You, sir, are highly skilled People just don't do this kind of repair anymore. Throw away and buy new.
Great videos. They show your love toward Amiga's. Please keep making them !!!
Awesome videos! You really have a talent for teaching things. I know 0 about electronics (I'm software engineer), but I feel like I really getting stuff from your videos. Keep up the awesome work!
I love your videos,They are so full of infomation and very interesting,I have Amigas too and will need to re cap mine soon. Keep up the good work..
Another great repair video. I enjoy the way you describe everything in detail and how the fault causes the behaviour as opposed to just repairing it.
Dooglesman
I'm glad you appreciate my approach to these repairs. I guess I could make my videos much shorter by just repairing the device and get it over with, but what kind of learning value would that have? It's always nice to get these machines up and running again, but I don't repair only for the sake of repairing. I also repair for the sake of learning new things and acquiring more information.
RetroGameModz I love the capacitor bypass trick. Simple and clever.
Indeed
This was absolutely BRILLIANT! I'm not an engineer, I'm more a user of computers (although I am a PC repair tech, we NEVER go this deep into repairs). If a graphics cars is broken, replace the lot is the way it works these days, rather than trying to find out WHY it's broken. Getting down an dirty like this is how I'd love to do the job, you just can't. I'd love'd to have seen you clean the connectors btw, maybe not all, but at least a couple, to see how it's done. Great vid. Subbed.
You're absolutely right. We now live in a 'throw away and buy new'-kind of society. Things are not what they used to be. I think this is sad, because it's almost as if people don't appreciate electronic appliances anymore. But that is from a user perspective. From an industry perspective, I think it also has to do with the more complex layout of today's PCBs and their components. If you have a graphics card that stops working and you still have warranty on it, they are not going to rework the GPU for you if that's in a BGA package. It's just too much work to do that, and it's also quite bit time consuming. And time is always money in the industry. So they will just make it easier for themselves by replacing the whole graphics card for you instead. It's probably much quicker, easier and cheaper for both the manufacturer and retailer to do so rather than repairing the board at component level.
Extremely interesting troubleshooting techniques, thank you so much for sharing this!
Wow what a climatic ending, very nice video. Learned a lot more about the effects of corrosion, cleaning, and what to potentially expect, it's not always BAD, but if it's bad it could be a broken trace bad... nice! And the RCA mono to stereo and how they work plus the little nipper at the end with the signal to turn on the left audio being a poor connection intermittently was a good find! loved it, if I ever get a chance to fix an Amiga and it has boot or audio issues I'll look right over everything I learned today. Much appreciated and great results man! thanks.
Forgot to add I really appreciate the demoing of amiga games/audio tracks for your videos, showing the scope and really going into high level of details which are fully appreciated. learning a lot from your videos! .
Learning a lot with your video!
Brilliant video! I've learned a lot about repairs. Thanks!
We must keep these historic functional addictive electronic works of art going for as long as we can,and with people like you around showing us how to..we will :)
10/10 for yet another excellent informitive vid and what excellent editing skills you have
Its a joy to watch and listen to your video's.Im even using them as background as im farming in wow or playing battlefield :-) Learned a lot, thank you.
Excellent video & repair job, I had a good time watching this for learning purposes :)
You have my sub, super professional and massively educational. Thank you for your excellent work and please upload more of your grate videos. Look everyone this is how it's done! ;)
Great detective work. Most interesting. You've got a subscriber. Thank you.
Thanks for the great video and lesson on repair.
Excellent video & descriptions.
Very nice video once again. It's becoming an habit with you ! ;)
Just my two cents about the corrosion: The Amiga could have been exposed to a localized source of humidity such as water spillage (obviously it's not coke or any other soda) which could have taken too long to dry if the amiga was still inside the case and stocked in a confined environment.
Awesome video as usual. Very interesting fault related to CS of CIA. Yet another Amiga saved from evil battery acid and leaked caps. Keep up the great work, it's always interesting watching your videos. Also learnt a bit about the audio mixing, I never knew Amigas did that.
That sounds like a very reasonable explanation to what might have happened to the board. A while back, I was also thinking about a possible case of the motherboard having been stored inside a cold and humid basement for a few years. But it then seems strange to me that the corrosion is very local and not spread out more evenly along the board. My thoughts therefore lean towards spilt water or any other substance that has some sort of corrosive elements in it.
Awesome video as usual!
Glad you liked it. :) Thanks for your support.
Everything is OK but you need to buy an ESR meter, I fix vintage audio equipment and this is the way.
Best Regards.
Super interesting.... awesome video
Thanks, appreciate it. :) Yep, you are right. Too many people are just throwing away electronics like if they were nothing but a pair of worn out underpants. Fortunately, most Amiga enthusiasts don't do that though because we all know that you can't just walk straight into your nearest local computer store and ask for an A1200. I think that's the reason why many enthusiasts of the Amiga systems still choose to repair their hardware, or choose to have the hardware repaired for them.
Good work!
Arrrgh I missed this video by whole two days ! What was I doing ! Great shame on me and my clan :( Great to see an A600 in your hands :) This video has some terrific things in it - a wiggle test and Bubble Bobble :D There is no way it can be anything less than exquisite :)
very great video to repair old computer :) thanks
I meant an expansion board with a clock - which apparently did exist in various forms. I think it's most likely that the Amiga was stored in such a way that the battery from the expansion leaked inside?
Hey! You are great and I really admire your job and knowledge. Awesome movie. Tell me just one thing, what kind of usb microscope do you use?
The mixing inside the RCA jacks is happening on several Amiga models. In fact, I think it's only the first Amiga models that doesn't have this feature. A600, A1200 and A4000 are all models that I know for sure has this feature, while A500 does not. If you compare the schematics between an A500 and an A1200 for example, you can see a difference between the circuits right at the RCA jacks, and actually see how this cross-connection works on the models that have it implemented.
i'm having the oddest issue with my A500 rev6 running Workbench 1.3 - When I turn on my A500 the green access light lights up and the floppy stays on trying to read a disk. When i place a disk into the drive it sounds like it grabs it and reads for a moment then it just stays making a click sound and every time the drive makes the click sound the access light flashes....?
Abit late to the video but people now are doing everything they can to keep retro gear going. Myself I have 4 Amigas 1 of which had issues on a board level and another had a dodgy floppy drive. All working now although cosmetically they need some love.
Great diagnostic skills, really enjoy following your projects.... I like your psu your using, I take it that the red terminal posts are set to different voltages? Can you do a video on converting a ATX psu for amiga use? Thanks again, please keep up the good work, very much appreciated.
Amazing videos. Nothing like it online. How do you film these things? I feel like I'm inside your brain!
Please make more of these.
well done tracking the fault on the pcb - nice video, do you think the corroded parts were from the rf shield which seems to rust? - I have just taken one to bits and the shield is totally rusty - and pcb brown with rust.
Thanks for the video. Great. Is it possible to do these things without a scope device you mention? I already have so much stuff in my room that I don't want to buy more things!
hi i own a amiga 500a and just wondering if you could help, when you turn it on the light flashes 11 times then on eleventh it stays on for a second then starts the sequence again. Screen shows light blue then dark blue any ideas would be greatly appreciated thanx scott
Hey @RetroGameModz ware can i find the probes you using in 02:14 i have a fluke machine.
I also wanted to ask with what exactly did you clean the corrosion and the traces, but saw that this one was already questioned/answered further below.
Did you use the USB "Salaelogic Analyzer" (24MHz 8CH) with the Software "Salae Logic 1.1.15"?
Brilliant with bypassing the capacitor and the furthermore investigation of the missing left channel...
Can you do a video on recapping Amiga A600 or A1200 and how you remove them,how did you remove the ones by the keyboard connector..?
I have 2 x 1200 Amigas,when i plug a flash drive into the IDE connector, it doesn’t seems to recognise it, normally the LED would light up, have you had any experience with this type of fault, or point me where i should be looking, many thanks john
Hello I have an Issue with my amiga 600 hard drive, suddenly stopped working, it seems that it's not powered, do you know where the amiga ide port gets power from?
Hello. Which logic probe would you recommend?
I see that You're a big Turrican series fan :)
That’s nuts!
My friend excellent diagnostic ! greetings from Argentina. I´m into micro soldering and chip level repair as a hobby. But there´s something I don´t have quite clear when you use the logic analyser. The trace which was corroded was carrying the CS chip select signal right?. That signal should be low for the CIA chip to be active. You hooked one of the probes of the analyser to _ODD_CIA pin of the CIA chip right ? but, if the line is corroded how can you see a pulse there?. That´s what I don´t understand. You say you´re seeing pulses on _ODD_CIA line at around 3 seconds trying to select the chip, ¨But¨ there should´t be any pulse on that pin if the line triggering the high-low state is corroded and isn´t carrying any signal ( well logic state voltage) ?. This confuses me, Can you explain it to me ?. thanks. By the way I have an amiga a1200 rev 1d4 which I bought and has no composite output, impedance on the RCA connector is 75ohms. Can you guide me ? some say Z222 might be damaged. I have oscilloscope and LA handy. Also I have an A600 which has a strange behaviour it boots rom shows on screen.. I load a game, after some time then I reset with keys.. and baam, black screen, and green power led starts blinking in different green levels. Then I turn off the machine turn on again and it boots fine. Sorry for such a large message ! many greetings and excellent video.
i would like to know how an what you used to clean it with please
i am not having your hardware at all but i am just repairing "by sight" with a zoom optic. One problem i almost got is in fact the keyboard which traces are printed (the right word ?) on plastic. Excuse my bad english at all, please. are there any ways to repair the traces on the "copper - on plastic" traces ? i read something about "silver finishing" it, like "re-painting". Did you agree ? And anyway great ! Realy a great repair video at all.
Very interesting question. You know, I haven't really thought about trying that for some strange reason. Maybe you could try it out and report back about it? :)
Hi!!...Great job..could you give me any advice about the equipment you use / is required for the soldering / desoldering of smt capacitors / components?? Thank you I really appreciate your videos!!! Wallmaker
That's a big question. It would require a whole video in itself to answer that question thoroughly, but in short I would recommend two soldering stations with temperature feedback (or one station with two channels so you can connect two handpieces at the same time), a hot air rework station, and also a preheater as your main tools for surface mount soldering and desoldering (not including reballing). The two irons (or as an alternative, desoldering tweezers) is useful for when you want to desolder SM resistors, capacitors and other components that only have two connection points. For chips, it's common to use a hot air rework station together with a preheater for desoldering, although other methods are available as well. For regular hand soldering (not including desoldering), you will mostly find that all you need is one soldering station along with some common accessories to go with that.
RetroGM , do you know any good amiga technicians in Vastra Gotaland ? , im dusting off my old A600 and it needs a recap i recon :)
That magnifying scope you're using is amazing, what kind of model/brand is it? I need one as well for my repairs. :)
I really wish I learned something like this at college and university.
Depends how the Amiga was stored - angle stored at. I've seen 500 and 500+ dmg where acid has reached some unlikely places on the board because they've been sat on side etc
There are several things that can corrode electronics except clock batteries and capacitors. One thing that battery acid (which is actually a base) and electrolyte has in common is that they both contain corrosive elements. Basically anything that contains corrosive elements can corrode PCBs. Pour coca cola on it and it will corrode (phosphoric acid / citric acid / minerals), pour water on it and it will also probably start to corrode (minerals), etc etc. And yes, moisture is very bad too.
Haha, it's not a spoiler, there's a tonne of interesting stuff to watch and learn from your videos - they cannot be summed up in a few words ;) I just assumed it was battery acid, but now you mention it... Maybe it had one of the few boards with a battery and clock? There must have been one board for the 600 that had a clock?
Unfortunately we won't be able to get any answer to those questions, because the owner bought the board in a non-working condition if I'm not mistaken, probably from ebay or something.
I didn't mention much about the actual cleaning process in the video, but the way you are suggesting is exactly how I did it. :) Except that I also cleaned up the vinegar with distilled water and then with ipa in order to not have the vinegar/acid corrode the board. And then soldered with flux, of course.
what method/materials did you use to clean it so efficiently? A video on that would have been amazing.
Great work I really like your channel, very informative, keep up the great work.
RetroGameModz That video would be greatly appreciated!
About the audio with the two channel mixing into one, i just discovered the same "feature" while restoring my playstation 1 SCPH1002 (the one with the RCA jacks) -> it was meant for the people only having the mono channel (it was quite common at the time for some TV to only have the composite + mono), so it mixed both channel on the rca. It's quite destabilizing when you find this the first time (and moreover there's no schematic whatsoever for this model). It had the same behavior with the RCA jack. Actually on this model i had an issue on the "echo" which was in fact done by recording the output mixed and put it back into the buffer with a delay. I fixed it by just cleaning / rethining the contacts on the RAM and audio chip. :-)
That broken trace is marked as "CS" on the "U7", maybe "Chip Selection" signal
/continued/
As I see it, these corrosion problems are located on the same side.edge of the board, it could have even "soaked" in water for a rather short time, but long enough to induce damage.
How was this Amiga stocked, how long and where? I think you will get your answer.
Regarding the repair and the corrosion cleaning, did you try the white vinegar technique ? It could help with dissolving the minerals which cover the insides of the vias and revealing the bare copper thus easing tinning
Ah, I see. Well, I guess it might be possible that the damage at 9:51 in the video is caused by a leaky battery on the expansion board, but I don't think it's very likely that the damage at 11:29 is caused by that since this area is very far from the expansion connector. The damage is also very local in different locations and not evenly spread out on the board. During battery leakage, usually only the nearby area is affected. To me this doesn't really look like a typical battery acid damage.
Tack för ditt svar
Du råkar väl inte bo i trelleborg :)
Tyvärr. Bor i Stockholm.
Also remember that even if the trace looks ok, it is very possible that the trace INSIDE the thru-hole could be corroded and open electronically.
Hmm... I'm not sure if there is a revision of the A600 motherboard that has a clock battery on board. I've never heard or seen such a revision anyway. But one thing is for sure at least; This particular motherboard doesn't have a clock battery, which means that there must be some other kind of underlying reason for the board having corroded. We will never be able to get a definite answer to what has happened to it, but LFO's suggestion about some spilt substance sounds very reasonable to me.
great video, you're a wizard :-)
I tried repairing a A500+ with bad damage from battery leakage - after adding lots of wire for bridging damaged traces on the PCB I get the bootscreen with the disk! :-) but it won't last: bootscreen crashes after some time (ranges from seconds to minutes, or sometimes I don't get a bootscreen at all) and Amiga shows "guru meditation addr: 8000 0004 task: 000 3e78" - does that behaviour sound familiar to you? any clues what to check next? (note: U12 received a lot of heat from soldering, maybe it became instable/damaged?) (note: power supply unit seems to be fine, tried different ones, same results)
As for my particular USB microscope, it's a noname cheap type from China. There is no brand written on the box. The hardware along with the drivers for it works surprisingly well, especially considering the price. The software that came with it however doesn't work at all and even crashes directly at start up. So I never use the software, I only use the microscope and drivers. Any photo or video editing program with capture capabilities will do the job as long as the drivers work.
Hej är du från sverige
Om så har jag en fråga som du kanske kan svara på
Jag har en amiga 600 när jag startar den så tänds power lampan caps lock lampan disk driven klickar till sen blir skärmen bara grå och caps lampan lyser hela tiden.
Undrar om du kan tänkas veta vad felet är den fungera för 2veckor sedan.
Mikael
Hej! Det är tyvärr omöjligt att svara på vad ett sådant fel kan bero på utan vidare felsökning. Det låter som ett systemfel, men exakt vad som orsakar det går inte att veta utan att genomföra några vidare tester, mätningar och undersökningar.
If you are curious about how disconnecting single wires can affect an amiga machine one diagnosis might be to use an FPGA model of the Amiga and artificially cut this wire in the Verilog model. The Minimig/MiST boards have cores which you can synth. You can then use logic capture techniques within the FPGA to produce traces of buses etc. Its alot of work to satisfy curiosity but it is possible. Since you're interested in early startup (usually) you could use Verilator rather than a real board. See my videos for whats possible.
All right. So there must have been almost any copper left on some of the most damaged vias then.
Good point that you underline: the vinegar is only the first step of the cleaning process.
I also read somewhere that a mixture of salt and white vinegar can be use to polish / deoxydise copper. I must admit I have not tried this technique myself... Did you heard about this ?
that is a really early revision of the A600 I have a Rev 2D a600 which i am restoring in a fantastic condition its had a kickstart rom change and isopropal is good if its corroding slightly from a little bit of water i dropped some water in a tv box and it did not work bit of isopropal and it was fine again
Hey you are still around!!
I've never heard about mixing salt and white vinegar as a means of deoxidizing copper, but I think it sounds extremely risky as I have noticed during a few tests on scrap boards that salt is very corrosive to PCBs, and if any grain of salt eg gets stuck inside a via... Well, it's quite easy to figure out what the consequences will be. I would only use such a method as a last resort if a board was so corroded that it was almost beyond repair. But generally, salt on a motherboard is a big no no.
If I was to guess I would say that was the Chip Select signal that tells the chip that it should wake up and listen to the address + data bus.
I need to fix my audio on my A600,it's the same but it's my right thats low
I guess you could say that, yes. I mean, what is there not to like about them? They are all great platformers with awesome music by Chris Huelsbeck. :)
However, I have to say that I don't like Turrican 1 as much as I like Turrican 2 and 3, and I have actually never completed Turrican 1 although I have played through Turrican 2 and 3 several times. But they are all really great game titles nevertheless.
My Amiga A600 only displays a purple screen.
Cool, I guess I remembered it correctly then.
Sorry, can't tell you what is coming next. That will have to be a surprise. ;)
My A2000 does the same thing! Self test 1 dark gray, test 2 light gray then boom black screen.
IPA! Does that work better than say a stout, or a lager? :D
How can anyone let there Amiga get like this,I guess it was stored for a long time.it looks like water damage.
You still fixing these
Isopropyl Alcohol Bath Time..Put a Little Wire thru the Hold and Solder it up Done, Now Long Wire..
Oh no, spoiler in the comments! Now everyone will already know what was wrong with the motherboard before reaching that part of the video. Just kidding, it's ok. :)
Yes, I also thought the symptom was rather interesting and kind of figured that others would think so as well. One thing that I'm still wondering about is how the corrosion got there in the first place, since there is no clock battery on A600 motherboards as far as I know, at least not on this one.
Hi, another great job. If you don't mind I need your miracle help to repair my A600, have corrosion over all ports. An unfortunately i can't find any seller who have DB23 Pins Male and Female to sell :/
Ian Stedman sells them here:
www.ianstedman.co.uk/Sales/sales.html
However, the problem is just that the ones he is selling are probably the regular ones that are to be mounted in a plastic shellcase. If you want to replace the ones on your motherboard, then you would need D-sub connectors that have a 90 degree angle on the pins so that they can be mounted on a PCB. Such D-subs, especially 23 pin ones, are nearly impossible to find these days. If that motherboard is to be saved, I think the best course of action would be to try to clean the board and get the corrosion off the connectors. I'm curious about how severe the corrosion on the connectors is. Maybe you could take some pictures of that and upload it somewhere, and then give me the link to those pictures?
Thanks for the quick response. I found one seller who have 23DB ports (www.pimfg.com/Product-Detail/2100-023P), but I don't like the aspect of the port, it's not similar to the original's find on the Amiga. Maybe I need to find one board for spare parts.
About the images please check this link imgur.com/a/VgR2t. and this one imgur.com/a/Ka2VP.
I wonder if you possible can repair my Amiga?
1NOM155 I have good and bad news, I was able to turn on my A600 and it works :), but the bad news I can't put my keyboard working, I'll already clean the contacts on the mother board and the green flat cable and underneath the keys with Isopropyl alcohol and also put a bit of tape on the back of the contacts to give a bit of force. but no luck, only get some keys working.
Also I notice the audio it's not great, I need to change the capacitors.
If really don't mind, I like your repair my Amiga.
BTW if you check the images I share the links, you will see i did some working on the back metal cover. :)
1NOM155
I can see that you have some metal oxidation on the connectors there, but the motherboard seems to be fairly intact otherwise judging from the pictures. It's probably worth trying to clean the connectors since the oxidation is not that severe.
I have a lot of repairs waiting in line already, but where do you live? Are you in Europe?
1NOM155
The metal cover looks nice and shiny btw. How did you treat it? I suppose it had some amount of corrosion earlier?
Sabotage in production procedures. Envy corrupts and actions can corrode. Namasté
Är du svensk? :)
Się gościu helu nawdychał??
Hehe... "ting tan ding dang"... :) Jakiś dialekt. :)