In the end, I had a change of heart for those working MT RAM chips and I reinstalled them in the motherboard. At least they are socketed so it would be trivial to change a failed one in the future.
@mikesilva3868
3 жыл бұрын
😎interesting
@catcam
3 жыл бұрын
thanks for that ... Happy Easter from Croatia.
@WilliamAndrewPhilipBodie
3 жыл бұрын
how can you write this a week before the video comes out ???
@catcam
3 жыл бұрын
@@WilliamAndrewPhilipBodie Patreons have video 1 week in advance ...
@ultrametric9317
3 жыл бұрын
That's the spirit :)
@herroncomm
3 жыл бұрын
I was working on a software problem for my job tonight, and I hit a wall and gave up and came down to my couch. I started watching your video, and how you kept powering through this troublesome motherboard's issues... and was inspired to go back up and solve my problem. I did. Thanks Adrian, you saved my company's deployment.
@MrSatellitehead
3 жыл бұрын
You need to start a One leg in the grave bin for those chips that still have a pulse.
@andrewsprojectsinnovations6352
3 жыл бұрын
Yes; it can be quite useful to differentiate between "marginal" chips from "completely dead" ones. The CG ROM from the first one produced glitchy artifacts onscreen but otherwise seemed usable. I'm not sure what you would do with a glitchy component if you have a fully working alternative, but maybe one day down the road it could be the only one available...
@OzRetrocomp
3 жыл бұрын
A Schrödinger parts bin, for chips that are both dead and alive?
@mrnmrn1
3 жыл бұрын
It would be interesting to see how a C64 works if it contains mostly or only marginal chips... :)
@andrewsprojectsinnovations6352
3 жыл бұрын
@@mrnmrn1 I'd love to see that
@DrakkarCalethiel
3 жыл бұрын
@@mrnmrn1 The G64, Glitch 64. The state of the machine will surprize you every time you turn it on! :D
@onetwothreefourfivesixlemo638
3 жыл бұрын
This channel is one of the few things keeping me sane recently. Only recently subscribed, so still got a huge amount of content to look back through.... Thank you!
@ikke1981
3 жыл бұрын
Not sure if the human malware situation is getting to you or something else, but hang in there.
@Okurka.
3 жыл бұрын
Looks at your username: are you sure you're sane?
@DrDavesDiversions
3 жыл бұрын
@@YoureUsingWordsIncorrectly The '040 @ 40MHz upgrade was the best part so far. Because of its clock rate, it beats my '040 Amiga/Mac Plus-based hackintosh that I posted a video about for #MARCHintosh. :)
@VenomStryker
3 жыл бұрын
@@YoureUsingWordsIncorrectly That was a great series. He just put a 68040 board in it. Thing is insane for an old Mac.
@disposablebasterd
3 жыл бұрын
“I don’t need another working NTSC board, I have enough of those.” ... Must be nice.
@laxr5rs
3 жыл бұрын
Key phrase, "falsely accused chip." We must fight against chip injustice!
@aphexteknol
3 жыл бұрын
Failed 6510 CPUs are very rarely seen in NTSC machines, and yet I've seen a handful of them on the imported PAL machines I've repaired over the years. I have a theory which could explain this; as over in PAL land the use of C2N cassette drives was far more widespread which connect through the CPU. Just like the famous theory of the exposed joystick port/joystick swapping being the cause of some failed CIA chips, its possible that over the years that something similar happens to PAL CPUs when cassette drives are plugged in/unplugged. Of course a cassette drive wouldn't be plugged in as much as joysticks, but its the only reason I can think of why PAL CPUs seem to have lead a harder life than our NTSC CPUs over here when they are otherwise the same. I've actually seen the bad zero page fault on a CPU before, as when they do fail (rarely) they tend to keep mostly working but glitch out on one specific test/function. Its strange.... -aphexteknol
@stephenwhite506
3 жыл бұрын
It is possible to determine bad RAM when you see different characters on the screen by looking up the character screen codes. In this case you could see $ in some places there should be spaces. The screen code for space is hex 20 and the screen code for $ is hex 24. So this indicates that bit 2 of the RAM is stuck high for some addresses.
@OzRetrocomp
3 жыл бұрын
You should set up an online store and start selling off those dead chips as genuine Adrian's Digital Basement merch, along with Rammy t-shirts. :D
@adriansdigitalbasement
3 жыл бұрын
Haha! Like encase them in resin to preserve them forever?
@Aruneh
3 жыл бұрын
@@adriansdigitalbasement Could make keychains from them. :)
@theViomax
3 жыл бұрын
@@adriansdigitalbasement Ya know, that's a pretty cool idea. I both collect glass/resin paper weights and display outdated hardware all over the pad. This would be a great combo of the two.
@danilko1
3 жыл бұрын
@@adriansdigitalbasement Then you can still use the bad parts bin, as is... Sell mementos to make more space, and support the channel at the same time.
@kwanchan6745
3 жыл бұрын
I would suggest removing the epoxy from the dead chips to reveal the semi conductor underneath encase the whole lot in glass or clear plastic and turn it into a desk ornament one day, when mobile phone cameras are ultra-ultra-ultra high resolution, the grandkids can zoom in on the chips and see where the circuit failed LOLOL
@daveharris3384
3 жыл бұрын
Adrian, just thought i'd mention the weirdest CPU fault we had, it took ages to resolve, but we had a C64 which would never increment the score when playing "Paper Boy" no other faults and Diagnostics passed everything... eventually tried a new CPU and all was fine. So yep i've seen a weird CPU fault as well! Keep up the good work, Dave H UK
@Frank-Thoresen
3 жыл бұрын
Congratulations with 100 000 subscribers Adrian. It confirms that you are on the right track.
@joshuareynolds6958
3 жыл бұрын
You're repairing pieces of my childhood to release into the world. That's something even I have failed to do. Love the channel:)
@kovacsdavid4362
3 жыл бұрын
So I just got rickrolled by a tiny cute monitor... You know what? I'll allow it.
@laxr5rs
3 жыл бұрын
Hahah!
@angrydove4067
3 жыл бұрын
I hate the little monitor thing, I got rick rolled so many times, I can't take any more. I wish Adrian would take that thing back to the Goodwill store.
@Anacronian
3 жыл бұрын
You need a bigger broken chips bin, when you get a new you should call it "The X-box" due to all the red X's 😃
@catriona_drummond
3 жыл бұрын
He could build a nice new big box out of hot glue and RAM modules :D
@0toleranz
3 жыл бұрын
Bad chips box out of an ugly broken trashed yellow breadbin- that should last for the next 5 years maybe 🤔 - and call it the X- box still ;)
@DrakkarCalethiel
3 жыл бұрын
@@0toleranz With all those dead parts, he would transform a breadbin into a deadbin 64. 😂
@Laceykat66
3 жыл бұрын
I love your opening credits. It looks like you reposted an old VHS episode. You even have some color bleed. Great job as usual. Keep up all the fine work you do.
@Charlesb88
3 жыл бұрын
It’s sort of like the intro to a 80s cable public access program. 📺📼
@qwertyuiop-ke7fs
3 жыл бұрын
i know nothing about computer hardware but can't stop watching
@zenninom
3 жыл бұрын
Congrats on hitting 100k subs!!
@AdmiralHorror
3 жыл бұрын
I am looking forward to "Adrian is building a brand new computer from the Dead Parts Bin" video.
@adriansdigitalbasement
3 жыл бұрын
Would be like Frankenstein :-)
@katho8472
3 жыл бұрын
@@adriansdigitalbasement I know this is another very long shot of mine... But would it be possible to use some chips that are "dead"/half dead with those functions/legs that are still working? Say, an address line isn't working, design the system that it doesn't need that line and so on.
@highpath4776
3 жыл бұрын
@@katho8472 that is sort of cheating. but interesting
@jonnycando
3 жыл бұрын
@@highpath4776 and once a chip has begun to fail, it’s only a matter of time before the whole thing falls flat on its face.
@Alphonsefisheater
3 жыл бұрын
Your' patience and enthusiasm for olde C64s is inspiring . So much so , that I have now bought a few olde computers and am in there solderring and desolderring to my hearts' content .
@nubieslayerkaka
3 жыл бұрын
With working 50 HR weeks this is what helps me get thru it thank you so much for the great content!
@SimonZerafa
3 жыл бұрын
"Dead Test Redemption" followed by "Dead Test Resurrection" as T-shirt slogans? Keeping with an Easter theme at least 🙂 Perhaps good game titles? 😉
@chepossofare
3 жыл бұрын
I thought about a nice idea for a video: an excursus about all the viable replacement for c64 chips (with eprom or even modern replacements)!
@michaelcarey
3 жыл бұрын
My Commodore 64 is a made in W. Germany model. It came with all of the main chips (CPU, ROMS, CIA, SID, VIC, PLA) in sockets. Very handy as I killed more than a few CIA chips playing around with the User Port.!
@davidegalliussi1979
3 жыл бұрын
seeing these machines working properly is a wonderful sight ... and then when it's a Commodore 64 there is empathy
@inferno10
3 жыл бұрын
The dead parts bin had quite the feast on this episode
@tenmillionvolts
3 жыл бұрын
Woo. 100k subs. Well done Adrian. Keep up the great work and 200k will be just around the corner
@DavidPlass
3 жыл бұрын
Great troubleshooting, as usual. I always love your enthusiasm, even when things fail!
@StofStuiver
3 жыл бұрын
If i remember well, there never was a soldered RF shield on the c64's in NL/Europe. I repaired dozens at least, back in the day. They didnt have a real metal shield to begin with; it was just flimsy cardboard with a metal layer on it with the thickness of alu wrapper for food and that connected to the expansion slots metal casing with a sort of sliding clip.
@JoeMcLutz
3 жыл бұрын
I'm wondering if "cooking" that CPU could solve that marginal issue... Nice video as always, see you Adrian! 👍🏻😊
@jeromethiel4323
3 жыл бұрын
The thing about diagnostic software, is to get the most out of it, you need to know how it does the tests, and how it interprets the tests. If you do not know how the test is done, you cannot trust the output. I used to have a whole suite of testing software when i was an IBM PC repair tech back in the day. And you could run several different ram test, and some would pass bad memory, and other would not. In then end, because i didn't have access to the source code of the testing software, you just learned which tests were good for detecting specific problems. For example some were really good at finding "slow" memory chips. Just because it says 250 doesn't mean it actually works at that speed. While others were very good at spotting "flakey" or intermittent bit errors. In short, that dead test may be small enough to reverse engineer by hand, if the source code isn't available. If it is, then use that to determine why the tests are seemingly giving you bad information.
@mojoblues66
3 жыл бұрын
I agree. I'd trust a working game more than I'd trust that tester when it comes to the zero page.
@danieltufvesson1349
3 жыл бұрын
In this case maybe the marginal CPU have one or more bad op-codes that are used by the tests and not in the tested game. I had a flaky 6502 many years ago that could not alter the D flag with SED/CLD. Since D flag is undetermined on power-on sometimes things worked but mostly not. Took me a while to track down. Maybe something similar happened here.
@volkerking5932
3 жыл бұрын
Best spech Adrian: (15:18) "Look at that that looks a lot more normal!" hehe Super I like it!
@TheRetroChannel
3 жыл бұрын
Very entertaining as always Adrian. I have to admit I was a little worried about that thermal compound that was on the VIC, it looks like it could be conductive and some of it appeared to be bridging some pins on the VIC. But after looking up which pins they are (colour and luma output) it probably wouldn't make a difference anyway as the colour from these old machines bleeds into the luma anyway 😄
@adriansdigitalbasement
3 жыл бұрын
Heh yeah, that white stuff is safe and non conductive. It's usually gooped all over everything and I've never found it to cause any issues at all, even for delicate circuits.
@MandrakeFernflower
3 жыл бұрын
@@adriansdigitalbasement it's likely zinc oxide aka old timey sunscreen
@stefarossi
3 жыл бұрын
Take a shot every time Adrian says "bad" 😂
@electronicengineer
3 жыл бұрын
Great troubleshooting Mr. Adrian. You impressed me a lot during this video. Thanks for sharing your masterful repair skills with all of us sir! Fred
@joshm264
3 жыл бұрын
I was given an Atari 800XL with almost the same issue as what was shown at the beginning of the video, and all it needed was Deoxit!
@jaoswald
3 жыл бұрын
I was going to say that I didn't see any Deoxit this episode. I wonder if any of the massive and confusing failures could have had a bad connection involved.
@highpath4776
3 жыл бұрын
@@jaoswald I was thinking it could be as much connections as chips.
@leandrocosta3709
3 жыл бұрын
I get absolutely amazed every time there's a Commodore repair video. Feels like C64's grow on trees over there or something. Never seen a Commodore in front of me before, only in magazines back in the day and I always lusted for one. At the time we mostly had TRS, Sinclairs or Apple clones. When the human malware is gone I'll try to get my damn dirty paws on one of those c64 maxis to get close enough to fullfil my childhood dream. Love seeing those repair videos!
@highpath4776
3 жыл бұрын
My dad picked up a few C64s from a Charity shop in surrey. He had no idea what to do with them. I sold them for about £20 each on the internet, about 15 years ago.
@Stoney3K
3 жыл бұрын
IIRC all of the PAL machines only had a cardboard/tin foil RF shield because the RF emission standards in Europe were less strict than the FCC ones.
@jschirr
3 жыл бұрын
Subscribed because of the intro. Great vids too. Takes me back.
@steiniapproved
3 жыл бұрын
Have you tried the character generator in your ZIF-C64 too? It would be possible that there were problems with contacts in the old socket otherwise. Maybe the other two chips just worked because they scraped away some dirt/corrosion in the socket. I expected some Deoxid before throwing the chip is the bad parts bin ;-)
@mariusberger3297
3 жыл бұрын
Great, I've been waiting for you to upload all day! Thank you for your content and Greetings from Germany!
@nefaurora
3 жыл бұрын
Adrian, I've been following your channel for about 2 years now... I love what you do and how you present it. Don't change a thing buddy...! Tony K., Melbourne, FL :o)
@MagnaRyuuDesigns
3 жыл бұрын
that sneaky RAM. goes bad and tries to take others with it LOL
@Nguyen_Phuc08
3 жыл бұрын
I have one of those C64 board, made in ´84 rev B. Bought it as "Spares and Repairs", replaced the caps and reflow the pins of the modulator and worked. Just yesterday brought it out for a "test run" and "poof" fuse blowed on it, replaced the fuse and now black screen. Those MT RAM on the board are hot to the touch, not sure why the fuse blowed though.
@frankowalker4662
3 жыл бұрын
Strange that the diag cart led you a merry dance. BTW, Congrats on 100K subs. :)
@ajslim79
3 жыл бұрын
wondering.. how many hours of "testing and soldering" were condensed into this 39 minutes video?
@theannoyedmrfloyd3998
3 жыл бұрын
I think by now I would keep a locally saved copy of the Dead Test manual.
@kajyakuzonik9130
3 жыл бұрын
Love your videos - keep 'em coming!
@cbmeeks
3 жыл бұрын
R.I.P. six working RAM chips.
@EngineeringVignettes
3 жыл бұрын
Gratz on getting to 100K :D
@MrGtagangster
3 жыл бұрын
Yes! I can't wait to watch! (have to wait, but I can't). Thanks Adrian for the awesome videos!
@Natures_Intentions
3 жыл бұрын
Wow big congratulations on hitting your 100k subscribers milestone. Many more to come. Great channel great content. A lot to be learned from your videos. These repair series videos are some of my favorite on your channel.
@rager1969
3 жыл бұрын
Wow, that second board was tough. When you put the RAM on the scope, you had some that showed weird data waves. I wonder if those were the bad ones.
@hansoak3664
3 жыл бұрын
In this episode, ZIF 64 pulls jury duty.
@Sheevlord
3 жыл бұрын
I think that RF shields are a US thing to comply with the FCC regulations. Other countries didn't have such rules, so products made for sale there often didn't have RF shields even if everything else was more or less the same as in the US version.
@PeterK6502
3 жыл бұрын
Not all 6502/6510 cpu's have the same instruction set. There are "undocumented" instructions which are not part of the standard instruction set, but which can still be used. However these instructions are not available on every 6502/6510 out there. Maybe the test cartridge uses some of these instructions, which could explain why the test game runs fine, but the tests fails.
@the_kombinator
3 жыл бұрын
My NCR (GMbH) 386 was made in West Germany. I miss that thing.
@Pedro8k
3 жыл бұрын
I have seen all sorts of so called repairs I even had a cpu with a minty smell coming from it when it was warmed up some expert had used a blob of tooth paste instead of heat sink paste it did not do the cpu any good another was silver foil wrapped around a blown fuse and half a biscuit fed into a floppy drive lol always look forward to your videos
@RocketCityTech
3 жыл бұрын
Whipping out a "thingy of ram" chips is possibly the most bad A move in the tech world.
@lisandro3614
3 жыл бұрын
That PAL machine was all over the place. Nice work! At this rate, the C64 community will end up developing a full drop-in RAM replacement. You clearly can't trust 40-year old RAM chips, regardless of brand.
@danielmantione
3 жыл бұрын
It's no problem and has already been done: You can use a modern SRAM chip and some glue logic to make it compatible with the DRAM interface. However, because availability of 4164 is really good and it is cheap, it is pointless, it is much more elegant to use original 4164 RAM.
@jasonc3a
3 жыл бұрын
I'm hoping that one day, one of the solutions to one of these problems is just going to be "cosmic rays", and a shield will have to be installed.
@viktoruzhgorod
3 жыл бұрын
The "marginal" CPU has most definitely it's I/O port damaged by ESD (this IS the type of board, that doesn't have any sort of ESD protection), that's why it does work, but zero page (the I/O port is memory-mapped to $01) shows damaged. Try testing it with a datasette - it most definitely wouldn't work. Other than that, there is no CPU-related stuff in the zero page.
@mnoxman
3 жыл бұрын
I think I remember seeing that you had a chip burner. One of the functions is also testing chips. For your pile of ram chips you might consider 'pre testing' them and then putting the good ones in to the black static foam and then in to a chip box. It would be a interesting set of data to collect on how the population of ram chips vs how many MT chips failed.
@c128stuff
3 жыл бұрын
So the lesson with regards to the dead test cart and the diagnostics is this.. the ram test in the dead test only tests the first 4k of ram, and not very thoroughly. It does not need ram to do this test, whereas diagnostics needs at least part of the zeropage and stack to work in order to start up. Due to not being able to use ram to keep track of anything, and the 6502 cpu only having 3 registers, the ram test in the dead test cartridge isn't just limited to the first 4k of ram, but also is not very thorough in how it tests ram. Ram chips can fail partially, and fairly often do, the dead test cart will often not catch those. The diagnostics use a series of test patterns aimed at exposing errors which won't show with a trivial test, so will catch many errors not seen by dead test. So.. always run diagnostics, and use dead test only for what it is intended for, figuring out why diagnostics wont start. If dt says ok, it only means it should be good enough to try run diags, not that the component(s) are actually good.
@jtveg
3 жыл бұрын
Great work. 🔨🔧🔩 Thanks so much for sharing. 😎👌🏼
@alerey4363
3 жыл бұрын
0:55 Murphy's Law at its best: just when u put the pieces back togethe and screw them...fail
@SpearM3064
3 жыл бұрын
I have a feeling that the problem with that CPU was probably pin 27 (called "P2" on the pinout), which is bit 2 of the built-in 6-bit I/O port used for bank switching. There's three banks of RAM that you normally control: there's the RAM under the BASIC ROM ($A000-$BFFF), there's the RAM under the Kernal ROM ($E000-$FFFF), and there's the RAM under the I/O registers ($D000-$DFFF). The dead test cartridge doesn't require the ROM chips to be installed, and probably starts with them already disabled by setting P0 and P1 low (the same as typing POKE 1,52 from BASIC). It seemed to work just fine with the ROMs removed. My educated guess is that pin 27 (P2), which controls access to the RAM under the I/O registers at $D000-$DFFF, is stuck high. The entire instruction set probably works just fine, which is why that game worked; I bet Dead Test crashes when it tries to disable the I/O registers and starts testing $D000-$DFFF. It probably doesn't realize that the I/O registers are still mapped into that space. So I'm also going to guess that when the dead test cartridge writes to one of the registers that controls interrupts (like $DC0D or $DD0D), it's inadvertently "arming" an interrupt without first setting up the interrupt vector. So the next time the C64 executes that interrupt, it's jumping to some random location in memory, causing it to crash or get stuck in a loop, depending on what's at that memory location.
@danielmantione
3 жыл бұрын
Dead Test disables the ROMs by means of Ultimax mode. The cartridge statically forces Ultimax mode, but in Ultimax mode only 4KB of the C64s RAM is enabled. Therefore Dead Test can only test the first 4KB of the RAM. In Ultimax mode, there is no way to access the RAM below $D000..$DFFF. (See www.c64-wiki.com/wiki/Bank_Switching )
@SpearM3064
3 жыл бұрын
@@danielmantione Interesting information. Testing the first 4KB will detect any stuck data bits, but it really doesn't detect if address bits 12-15 are stuck (since that memory isn't even mapped in Ultimax mode), so I was assuming that a full RAM test was actually a _full_ RAM test. Evidently not. I still think my theory is a strong one. We'll never find out unless Adrian runs more tests on the CPU, and what would be the point in that? We know it's _obviously_ got something wrong with it, even if the full instruction set works.
@danielmantione
3 жыл бұрын
@@SpearM3064 I'm not sure what you mean with "full test". There is no logic on the Dead Test cartridge to get out of Ultimax mode, this means that from a software point of view there is absolutely no way to access RAM outside the first 4KB of memory as long as the Dead Test cartridge is inserted. For a "full" RAM test, you need the Diagnostics Cartridge.
@MD_il_microcanale
3 жыл бұрын
good job Adrian!!!!
@MadManDarkJedi
3 жыл бұрын
I love the see happy ending, both C64 fixed.
@micahcowan
3 жыл бұрын
Seems like you'll have trouble getting the lid back on the"bad parts" tub. Perhaps that's why you resocketed those borderline ones? 😄 Might be time to start a new tub (or just start throwing things out, or using them in creative crafting projects)
@alanharkleroad4376
3 жыл бұрын
Congrats on 100k subscribers. Now you need to get a bigger bad parts bin.
@chadhartsees
3 жыл бұрын
Is there any chance of bad chips causing good chips to go bad? IE: is there a risk of putting known working hardware in danger whenever you're troubleshooting? Love the channel BTW!
@DanielBartholomew
3 жыл бұрын
Excellent video as always. Sad there was no working 8-bit Dance Party due to the bad sid.
@adriansdigitalbasement
3 жыл бұрын
I am pretty sure one is coming up in the next part :-) (Or was it in part 4?)
@cheapasstech
3 жыл бұрын
Adrian, I have a bunch of SIPP memory in my parts bin; I’ll check which ones they are. The pins look like the Greek letter mu from the side, ie they clip onto the pcb on both sides
@The_Wandering_Nerd
3 жыл бұрын
MT RAM? More like "empty RAM!"
@repetto74
3 жыл бұрын
Hi Adrian. Always watching your videos packed with interesting informations on Commodore machines :-D. I have a question for the VIC-20 character set used on the Commodore C64. Is this just the binary for the Vic20 chr rom or is that something special? I would like also to burn a 27C64+adapter to have the VIC-20 font.
@knaperstekt7953
3 жыл бұрын
If the reference ZIF-board would develop an intermittent issue for any reason, Adrians sanity would probably plummet when checking for faults on new C64:s. Lol. I need to make myself something similar.
@kevincozens6837
3 жыл бұрын
Good work on diagnosing the problems on the PAL machine and bringing it back to life. f you have a TL866 why don't you use that to do preliminary tests on some of the ICs instead of always testing in a machine?
@stevencarlson5422
3 жыл бұрын
seems like you going to have to try some chip baking again with all those dead parts, im curious to see if the sid would come back or even if that bad cpu could be revived lol
@ultrametric9317
3 жыл бұрын
So probably a bad power supply zapped the RAM and partially zapped the CPU, would you say?
@pipschannel1222
3 жыл бұрын
Yep, the German PAL Rev. C C64s had the ugly cardboard heatshields. I always toss them in the bin :-)
@coleeau
3 жыл бұрын
Just a quick note. MT usually stands for micron technology or micron
@EwaldBurger
3 жыл бұрын
Great troubleshooting as always. I do enjoy these repair video’s although i never owned a commodore 64. In the early 80’s i had my home made Acorn Atom that came as a kit. Learned so much of that machine. Back to the repair: I wonder if there could be a slight chance that the bad SID could cause the original microprocessor to behave seemingly abnormal. You only tested the supposedly bad uP in combination with the bad SID in both the ZIF machine and the #2 machine. Indeed you did test the combination of bad SID and a known good Microprocessor from your ZIF-machine in the #2 machine, but did not test supposedly bad uP with known good SID. Might e.g. be drive tolerance that makes one uP experience issue with bad SID and the other not. Again, i have no experience repairing C64 and don’t know in which way the SID is connected to the uP (i did not search for schematics) so maybe i am totally wrong here. Just a suggestion out of curiosity and because the failure mode of the uP seems very odd/marginal. Keep up your interesting repair video’s. Regards, Ewald
@EwaldBurger
3 жыл бұрын
Ok, i admit i am stupid. Just started watching part #3 and see the first thing you do is removing the SID before you start testing. Went back to part#2 and of course you did the same thing there. Missed that for some reason. Regards, Ewald
@station240
3 жыл бұрын
The 65xx CPUs have zero page specific opcodes, some of which are rarely used. Your average game isn't going to be doing fancy stuff in zero page, but RAM test certainly would be. Others mentioned the 6510's six extra IO pins (which control memory bank switching and other things) could be bad also, guess that could be be a cause. Should be easy to write some code that uses all the different zero page opcodes, figure out what's bad.
@christianhansen3590
3 жыл бұрын
This is wholesome content!
@JonathanBastienFiliatrault
3 жыл бұрын
I think I saw cracked ceramic bypass capacitors on the RAM chips, might explain some of the wonkyness.
@jazbell7
3 жыл бұрын
You have to get a bigger "bad parts bin" or maybe "empty the trash".
@AureliusR
Жыл бұрын
At around 22:41 I count FIVE flashes, not six, which was odd.
@mohinderkaur6671
3 жыл бұрын
Check for damage from overvoltage - looks like that was the cause. 5watt zener diode 5.1 volt or a crowbar should prevent further issues
@doktor6495
3 жыл бұрын
Hey Adrian! Waiting for the 100k subscriber video! ;-) CONGRATS! Greetings, Doctor64!
@MrHeem94
3 жыл бұрын
TSK TSK TSK...Oh the bad machine doesn't know its a bad machine....Wanna know how Adrian knows? He's from the factory, he makes the machines.
@GummyGruffi
3 жыл бұрын
Semiconductors shortages are so bad in 2021 people have to repair and use Commodore64 computers.
@Eyetrauma
3 жыл бұрын
We have a saying here in Derry, Maine: don’t look into the DeadTest
@ImaginationToForm
3 жыл бұрын
I was thinking of buying a C64 for nostalgic purposes but seeing what you do to have to make one run puts me off. I don't have an oscilloscope at all.
@chriswatson2407
3 жыл бұрын
"Dead-test Redemption"
@SimonZerafa
3 жыл бұрын
That's another T-Shirt slogan along with the others 🥴🤷♂️
@tubeDude48
3 жыл бұрын
At 13:20, those are called Pinned sockets.
@dr.ignacioglez.9677
9 ай бұрын
I REALY LOVE MY C64 ❤❤❤❤ FOREVER ❤❤❤❤
@Okurka.
3 жыл бұрын
Viewers send special pens to write on the dark ICs; Adrian keeps using a black Sharpie.
@DavePoo
3 жыл бұрын
26:10 - Yes i am watching!
@Jody_VE5SAR
3 жыл бұрын
Great video! I enjoy watching your mind at work - I literally ask a question in my mind about "why not try this?" and you do it as the very next thing. But you left a cliffhanger for me - I wanted to hear an actual working SID in the repaired machine - just to prove out everything was fine in the audio cct. :-)
@mutetus
3 жыл бұрын
Inspired by this video, I finally decided to burn that diagnostics rom chip for C128 and find out why nothing works in 128 mode. Guess the manufacturer of the broken memory chip (which the "function rom" version of diagnostic rom got spot on). And that was the third one I replaced in the same computer. I'd rather swap them all, but these boards are painful to desolder without the vacuum desoldering pump... thingy... Especially because the components' legs are bent just a tiny bit. I use a separate manual pump, it does the job but it takes so much time. I have the same job ahead of me with rev 4 Amiga 2000 board, which also has 16 memory chips, and doesn't even boot with diagrom.
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