Amiga 1200 Escom Floppy Fix quick tutorial RetroGameModz 2013-04-01 | This is a very quick tutorial on how to perform the Amiga 1200 Escom floppy fix.The fix is very simple and requires very little soldering.After applying the fix, it's possible to hook up an Amiga compatible shugart interface based floppy disk drive to your Escom Amiga motherboard, and use that floppy drive together with your motherboard while having it work in exactly the same way as it was first intended by Commodore.For any questions or thoughts regarding this floppy fix, feel free to let me know in the comment section.Happy floppy fixing! :)
Amiga 1200 repaired by recapping... or not? RetroGameModz 2013-10-04 | I first started working on this 1D.4 Amiga 1200 motherboard because of two reasons. The first being that there was some kind of instability in the picture while the hard disk was loading. The second problem was the RF modulator not producing any output signal.But as often during repairs, I ran into some other problems along the way that I had to deal with as well...Note:It looks as if there is a crack in the solder joint on the ferrite bead at 1:07:38. I thought it was a crack at first, but it was still there in the same shape and formation ever after resoldering the joint. I also did not experience any intermittency problems at that joint. I then realized that it must be some kind of light reflection from another component on the board. The USB microscope I'm using has very bright LEDs which, due to reflection, sometimes makes it "see" things that aren't actually there. This is most often not a problem, but it can be a bit misleading at times.Link to the Aminet archive that I mentioned in this video:http://aminet.net/package/docs/hard/flickfixThread on English Amiga Board about this motherboard:http://eab.abime.net/showthread.php?t=70334The ACA1220 accelerator problems mentioned in the thread on EAB was all due to a fault in the ACA1220 card and had nothing to do with the motherboard. Therefore, this accelerator issue is not being discussed at all in this video, since the main focus in this video is on the motherboard itself.More info on this accelerator issue can be found in the thread about this board on EAB.
Amiga 600 repair - Boot problem RetroGameModz 2013-09-16 | 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.
A1200 floppy drive repair - sensor problem RetroGameModz 2013-08-04 | Here is an A1200 shugart floppy drive that was claimed by the previous owner to have a problem with the disk write-protect functionality. The drive was given to me since the previous owner has already gotten himself another drive, and he felt that he didn't have any use for this faulty floppy drive anymore.As it turned out, there wasn't really any problem with the write protection functionality, but there was another problem with the drive instead. I took a look at the drive and found out that it was a very simple thing to repair.In the video, I'm testing the disk drive as far as I can using the drive tester program. It's of course possible to perform even more extensive tests, but that requires the use of test gear like an oscilloscope for example, which is way beyond what was needed in order to have this floppy drive fully working again.I would say that this type of failure is one of the most common ones on 3.5" floppy drives. And luckily, it's also one of the easiest failures to repair.Again, this is just a documented repair and is therefore not meant to strictly act as a tutorial. This video is also a little bit more off the cuff and more "real time" than most other videos I've posted so far.I've made some cuts to shorten the length of the video a little and remove some unnecessary things I said that really wasn't necessary for the purpose of the repair, but that's about it.As always, comments and questions regarding the repair are always welcome.The test program used in this video can be found on www.aminet.net as "DriveTest.lha".
LCD TV repair - Samsung LW20M21CP not powering up RetroGameModz 2013-07-08 | This is a documented repair of a Samsung LCD TV that I got for cheap. It was listed as not working, which is why I could get it for a really good price.In the video, I show you how I disassemble the TV as well as how I go along fixing it.This video is not meant to strictly act as a tutorial, but you might still be able to pick up a few ideas here since this particular cause of failure seems to be quite common on Samsung TVs and monitors.Disclaimer - If you attempt to do what I've done in this video, you can only blame yourself if things go wrong. I'm not responsible for any kind of personal injury or material damage as a result of trying to follow what I have done in this video. Neither am I responsible for you catching a cold, losing your job, or getting struck by lightning during a thunderstorm. I can also not be held responsible for any kind of nuclear war starting as a result of you trying to copy what I've done in this video. And I can not be held responsible if a meteor hits our planet earth and wipes out your neighborhood as a result of you trying to execute any kind of procedure that is being done in this video.So in other words, I am simply not responsible for ANYTHING! :)
A1200 repair - no audio & much more RetroGameModz 2013-06-01 | This Amiga 1200 motherboard first came in with an audio problem. It was easy to see during initial inspection that this motherboard had been "recapped" earlier. I was not very impressed by how the solder joints on the electrolytic capacitors looked like...In fact, the extremely poor solder job done on this motherboard by the previous recapper was the reason the motherboard had to come in to me for repair in the first place.In this documented repair, I go through the process of locating and repairing the audio problem. I also put some focus on the solder job, as well as a few other bits and pieces that I wanted to fix up before sending the motherboard back to its owner.I also present to you a rather stupid mistake I made during the repair of this motherboard in order to make it possible for you guys to learn from my mistakes as well.I then perform a lot of testing before finally packing the motherboard and sending it off.The message from this video stands clear - If you do not have the right tools and skills to solder, you might be much better off just leaving your motherboard alone. Because soldering without any knowledge of how to do it right means that there is a big risk of damaging the motherboard, which can actually make it work worse than it did before. This whole repair is a very good example of such a result, since the motherboard would never have come in to me for repair if it hadn't been for the horrible work performed by the previous recapper.It is of course not possible to learn how to solder without a bit of practice first. However, there are lots of electronic equipment out there to practice on, like scrap PC motherboards for example. In my opinion, Amiga motherboards should not be seen as solder practicing PCBs.We, the people of the Amiga community, need to take good care of the hardware in order to preserve it. Anyone who cares about the maintained existence of Amiga hardware should realize that soldering onto the motherboard without any knowledge of how to do it correctly will most probably destroy the Amiga more than it will preserve it.So if you have an Amiga or other piece of retro hardware that you want to have repaired, and if that repair requires soldering, I would recommend you to ask someone for help if you don't feel absolutely comfortable doing it yourself. This goes especially for hardware that you care about and want to preserve.If you choose to not follow this advice, it's possible that your motherboard will end up lying on my workbench one day... :)The transparent tape used in the video to attach the wire to the motherboard:Google for "Double Sided Tape with Red Release Paper and Transparent Foam".If you live in Sweden, you can buy it here:http://www.clasohlson.com/se/Monteringstejp-Super/31-1633The yellowish tape used in the video is called "kapton tape" or "polyimide tape".Ebay, amazon, your local electronics store... It can be found just about anywhere.Feel free to leave questions and comments in the comment section for the video.
Amiga demos on oscilloscope RetroGameModz 2013-03-29 | Here is some footage of a few Amiga demos displayed on my oscilloscope. The composite video signal coming from my A1200 is fed into a circuit which, with the help of OP-amp based constant current sources, creates linear ramps from the vertical and composite sync signals. Those two ramps are AC coupled and LP filtered before going into the scope in X/Y mode.The composite video signal is being inverted and amplified in an OP-amp which is set up as an inverting amplifier, then going through a negative unbiased clamp before going into the Z-input of the scope.With different trimpots, I can adjust the width and height of the image as well as the contrast. The brightness of the image is set by adjusting the intensity knob on the scope.I originally got the idea from this YouTube video:http://www.youtube.com/watch?v=5FYF5uhCzAMI decided to start experimenting on my own around this idea, which led me into an OP-amp based solution.Clips from four different Amiga demos are included in the video. These are:00:00 Andromeda - Nexus 702:30 Balance - Syndrome05:21 Sanity - Interference08:56 TBL - TintThe picture looks noisy in the video, but this is only because of the crappy low light capabilities of my camera. The picture on the scope is way less noisy in real life.Generally speaking, it was actually really difficult to capture this on camera in a way that makes it justice. YouTubes encoding process when uploading also changes the light conditions a bit, which makes it look even worse.But I wanted to share this with you anyway, just for the fun of it. :)
Amiga 1200 rev 1A audio fix RetroGameModz 2013-02-22 | Attention all owners of Amiga 1200 rev 1A!In the audio circuit on the A1200 rev 1A motherboard, the gain of the OP-amps is set very high. In fact, it is set so high that portions of the swing of the audio is reverse biasing the polarized AC coupling caps C324 and C334. Also, the high output coming out from the RCA-jacks at the back of the A1200 rev 1A might drive some amplifiers into distortion.The reason for this is that the feedback resistors R321 and R331 going to the inverting inputs of the OP-amps are of a too high value, which makes the OP-amps have a really high gain resulting in an audio output with a very high amplitude. The value of these resistors is 1.5 kOhms. Commodore recitified this mistake in later revisions of the motherboard. In revision 1D4, we can find 680 Ohms resistors in there instead, which sets the gain of the OP-amps to a more decent level.This is all being demonstrated in this video.Revision 2B and 1D3 are now also confirmed to have the 680 Ohm resistors on the motherboard. If you find another revision other than 1A that has the 1.5 kOhm resistors on the board, please let us know in the comment section.The motherboard in this video is the very same one as the one that had a color problem earlier, which I featured in another video. Feel free to have a look at that repair as well. The video can be found here:http://www.youtube.com/watch?v=8xlG9Ln5o30
Amiga 1200 color problem repair RetroGameModz 2013-02-21 | This Amiga 1200 motherboard had some sort of color problem. During some testing, I noticed that the only color that showed up correctly on screen was the green one. Both the blue and red color was behaving improperly as I was moving the color slidebars for each color respectively in ProTracker.I have here documented the repair process of this motherboard, including the steps of initial testing and problem observation, circuit analasis and diagnosis in order to track down the problem, futher testing for fault verification, and finally replacement of the components.On the very same motherboard, there was also a problem with the audio which I figured out was not related to this board in particular, but most probably a problem on all A1200 rev 1A motherboards. Later revisions are not affected.However, this video is dedicated only to the color problem. I made another video regarding the audio problem, so feel free to have a look at that one as well. :)http://www.youtube.com/watch?v=7sZ7vLcURK4Questions and comments regarding the repair of this color problem are always welcome.
Amiga HD floppy drive repair - Chinon FB-357A RetroGameModz 2013-02-08 | This is just a quick and simple repair of the Chinon FB-357A high density floppy disk drive. This drive was inside an Amiga 4000 that I was working on. It had intermittent problems with the 'disk in drive'-detection.I also cleaned the heads with a little bit of alcohol while I was at it, which is not included in the video.
Amiga 1200 repair - Video problem RetroGameModz 2012-11-02 | I'm here taking a look at an A1200 motherboard that suffers from two problems, both related to the video output. One problem is that I'm not getting any picture from the RGB output. The other problem is that even though I am getting a picture from the composite video output, the picture that is coming out from there is distorted in some weird way.Blog #4
Video response - Amiga Floppy Strangeness RetroGameModz 2012-10-23 | I am here analyzing a certain problem that a YouTuber is having with all his floppy disk drives (internal & external) connected to his Amiga 1200. I am also giving him a few ideas of what can be done in order to fix this problem.The person whom I am responding to has made two videos about his problem. Those videos can be found by searching for "Amiga Floppy drive strangeness" or by following these links:watch?v=1WhPm_HK9Vwwatch?v=tLKsNiVDiUMThis YouTuber is experiencing a problem with the write operation. When formatting a disk in Workbench, it appears as it is being formatted, but after the screen with "initializing disk" is displayed, the disk icon will just pop up on screen as before, with the same content still on the disk.I hope this video will be helpful to the person having this problem, and that he will be able to fix his A1200.If you have any questions about this issue, feel free to let me know.Blog #3
RetroGameModz channel introduction RetroGameModz 2012-07-20 | This is just a little introduction video to my channel here on YouTube.I am often doing a lot of repairs and modifications to different retro consoles and computers, so I thought I might just as well start a video blog about it so that people who are interested will be able to follow me on what I'm doing.Some of my videos might be a bit technical, while others might just contain a very simple modification. It all depends on what I'm working on at the moment. My goal is to make a video about every retro repair/modification I do, regardless of the difficulty of the task at hand, and regardless what kind of repair or modification I'm working on. If it's about retro computing or retro videogaming, it will fit in this blog. :)The reason for making this video is actually not just to introduce my channel, but also to learn and get some practice with the video editing software that I'm using.The length of my videos that I'm going to upload on this channel will completely vary depending on how complicated the repair/modification is that I'm working on. So for those of you who prefer to watch quick 4 or 5 minute tutorials... Well, don't subscribe to my channel, because some of my videos might become a bit long. ;)I am not aiming for making tutorials in this channel, but if you have any question that has to do with retro computing & videogaming repairs/modifications, you can always ask me if I can make a video about that. I might as well do it, if I find the question interesting enough. :)I am not yet sure about the future of this blog. That depends on what kind of response I get from the viewers, and if there will be any interest in my videos.-------------------------------------------------------------------------------------------------------------By the way, depending on your browser, the audio and video might be slightly out of sync, due to YouTube processing the video after upload. Although I managed to compensate for this in my video editor to some degree, the results after uploading are still slightly different from the original video. The intro text is in perfect sync when I play the clip locally on my computer, but is unfortunately not on spot in sync anymore after uploading it to YouTube. I also experience the sync to be slightly different depending on which webbrowser I use to watch the clip.And I thought it would be cool to have the intro text sync with the music and all. Oh well... :)-------------------------------------------------------------------------------------------------------------Disclaimer:This disclaimer is valid for all videos that I upload to this channel on YouTube.If you apply any kind of information or technique that I present in my videos to your own repairs or modifications, I will not be held responsible if your motherboard (or whatever you are working with) catches on fire and your whole house burns down to the ground. I will not either be held responsible for any harm caused to any person as a result of watching my videos, like for example your head exploding violently causing a fatality. If that happens, in the unlikely event that you are still alive after your head has exploded and you feel like trying to sue me, keep in mind that you are responsible for your own actions and that you don't have the right to blame me or anyone else for any kind of damage or harm you have caused to any equipment, material or any living thing.Your head will probably not explode if you try to copy anything I do in any of my videos on this channel, but if it does it's not my fault and I can not be held responsible. :)
