Hello, and welcome back to The 8-Bit Guy.
  So, in this episode, what I'm going to be  doing is a complete restoration of this IBM
  PC jr.
  Now, this was recently donated to me by Sean  Hafeez, and it's actually not in bad shape,
  but it actually does have a problem with the  monitor and the keyboard.
  So, let's see what we can do to fix it up!
  Looking at this system, cosmetically it is  in pretty good shape and just needs some minor
  cleaning.
  But the keyboard is noticeably yellowed compared  to the computer.
  It also has some nasty gunk between the keys,  which shouldn't be too hard to clean, but
  it is also missing the little silver badge.
  The monitor is a different story.
  As seen here in the original unboxing video,  the monitor doesn't work, even though it
  was working before Sean shipped it.
  Since the PCjr has a proprietary video connector,  there was no easy way to test this monitor
  on another system, so I plugged in a composite  monitor to the PCjr to verify the computer
  was working.
  After that, I took the monitor partially apart  to look for anything loose, but couldn't
  find anything.
  Eventually, I discovered that if I whacked  the side of the monitor, it would come on
  for a short time, but the picture was unstable.
  So we'll come back to the monitor later.
  For the moment, let's have a look at the  keyboard.
  This thing has a lot of black scuffs on it,  some that don't show up well on camera.
  So, I'm going to use one of my tried and  true methods, where I just put some baking
  soda on a paper towel and then wet it with  water until it becomes kind of a mushy paste.
  This works extremely effectively on this keyboard.
  Here's one on the side that wouldn't come  off easily with windex or alcohol.
  And it just wipes away in seconds with baking  soda.
  Once I'm happy with the exterior, I decided  I should open it up, for a number of reasons.
  For one, it will make it easier to clean the  keys, but also I want to retrobrite this thing.
  While removing the screws on the bottom, I  also noticed that it has these little rubber
  feet here, and one there, but it is missing  this one.
  So I will have to find or fabricate a replacement.
  Despite removing all of the screws, I couldn't  get the keyboard open.
  Feeling around on this label, it felt like  maybe there was a hidden screw under there.
  And sure enough, there it is.
  After removing that, it opened up easily,  and oops..
  I forgot to take the batteries out of this  thing.
  Ok, here's the circuit board, and here's  the little rubber contact mat, which appears
  to also double as a spring for each key.
  This thing is pretty filthy and will need  to be cleaned up as well!
  I wasn't sure how the keys came out at first.
  Looks like the space bar comes out easily  enough, as does the enter key.
  It appears the keys just pop off with some  force like this.
  So, I thought maybe I should get out my key  puller and use that.
  And while that does work, it occurred to me  that it might be easier just to push them
  out from the other side.
  And that works fine too.
  The easiest way to clean this mat was just  a good spray with the hose.
  Then I gave the keyboard a good spray as well.
  And here they are.
  They aren't fully dried off yet, but you  should already be able to tell a big improvement
  there.
  Although, it's interesting how it has this  discoloration now.
  And plastic seems much improved as well.
  OK, so this is a little bit of a mystery before  I start the retrobrite.
  If you look at the actual PC junior's case  color and compared to say, this space bar,
  the color matches perfectly already.
  I see no reason to attempt to treat these  keys at all.
  But, when you compare to the keyboard case  itself, the keyboard is noticeably more yellow
  than the computer.
  I think it may be less visible on camera,  but there is clearly a difference in person.
  But here's where things get interesting.
  The inside of the keyboard is essentially  the same color as the outside.
  This typically indicates that this may be  the original color of the keyboard because
  UV light damage willl usually just affect  the outside.
  So, I am not 100% sure if what I'm about  to do will change it any.
  But I do know I want to take some alcohol  and remove the residual adhesive from this
  little badge area here, because I plan to  fabricate a new badge.
  And it looks like alcohol did the job for  that.
  Now, all of the keys on this thing are dirty,  but 4 or 5 of them have this really sticky
  gunk on them like this.
  I tried using windex, and later alcohol and  neither one made a dent.
  However, I found that I could use my fingernail  to carefully scrape the gunk off.
  After that, alcohol removed what residue was  left.
  And this is the finished key.
  So, now just to do the rest of the keyboard.
  Since the keyboard is fairly small, and to  avoid any streaking, I decided to use the
  submersion method on it.
  I filled up a small bucket of water, just  deep enough for the keyboard.
  And one concern I had was that the back of  the keyboard had a lot of air pockets and
  I wasn't sure if it would sink or not.
  Fortunately, it did.
  I'll be using the clear salon developer  liquid.
  And then I'll let this sit out in the sun  for a few hours.
  And while that's going, I thought I'd  turn attention to the monitor problem.
  OK, so, for the CRT part of this problem,  I thought I would enlist some help.
  So, I know my way around a CRT a little bit,  I've done videos on CRTs before, but I am
  by no means an expert, and so I thought I  would ask DJ here, who lives in town, he also
  runs a YouTube channel doing all kinds of  old retro computer junk too, so I'll put
  a link down in the description.
  Anyway, he knows a little more about CRTs  than I do so he's going to help me out with
  this.
  Hey y'all, I'm DJ and I'm not an expert  with monitors either but I've had a lot
  of experience with them over the years and  I've learned a lot from one of the modern
  experts in CRTs.
  And there's only a few things that are probably  wrong with this thing given what its doing
  right now.
  And the one thing that I think we're probably  looking at here is something to do with the
  flyback transformer.
  This monitor was working before it got shipped  here and upon arrival it was intermittent
  or non functional.
  And typically what this means is that the  flyback transformer, which is a big heavy
  part mounted on top of a PCB probably had  some rough handling of the entire monitor
  during the shipping.
  It's a miracle these days that you can ship  a CRT and have it arrive in one piece.
  But, with that flyback transformer getting  jostled around it's quite possible that
  it's broken solder joints or possibly cracked  a trace on the PCB and so, what we really
  need to do is just kind of open it up and  see what we're working with and see if we
  see anything that stands out.
  So, DJ got to work disassembling the monitor.
  Of course, I had already done this myself  but hadn't gone any deeper than than just
  taking the cover off.
  So, let's turn it on here and see what happens.
  Hey!
  We got high voltage!
  So, we already knew that that was intermittent.
  But, what I wanted to turn it on for was to  check and see if we could tell that the heater
  was glowing.
  And I do see the heater glowing.
  Just faintly.
  I actually had to turn the lights out in the  room and make it completely dark before the
  camera was able to really see the heater glowing.
  Well, that tells us that the heater is not  the problem.
  I just wanted to see if the heater was going  to come on, but we got high voltage this time,
  so something changed regarding the orientation  of the machine, or us banging around on it
  trying to get it disassembled.
  All right, so when we had it face down and  we were working on it, we noticed it was turning
  on every single time that we tried to turn  it on and had a picture every time.
  And then, we flipped it down to this orientation  and it stopped having any high voltage.
  If I turn it on at this point, it kind of  goes whit, but it doesn't make any high
  voltage.
  But, if I flex the board, it comes on.
  And so I suspect we've got either a bad  solder joint or a broken trace.
  So, even though I don't think this thing  is charged any high voltage, I want to make
  sure the tube is discharged before we mess  around with it too much more.
  So I will hook onto the DAG ground there.
  So this screwdriver is now grounded.
  And we just get it up under the cup.
  And there was no curpaps.
  So, it's not charged.
  All safe.
  After discharging, DJ started to disconnect  all of the cables so that the boards could
  be removed and examined more closely.
  During manufacturing they had placed a big  blob of what looks like some kind of silicone
  like they use for windshield sealant.
  Anyway, we couldn't get it loose so DJ just  sliced it off with his knife.
  Finally, we had all of the boards disconnected.
  OK, so we noticed this from the other side  as we were disassembling it and we suspected
  that there was a crack, but here is a big  ole crack that goes clear over to here.
  And it cuts, it possibly cuts through this  trace, definitely cuts through this trace
  cuts all the way across this solder joint,  then there's this gap here, an air gap for
  this transistor, but on the other side of  it, it continues across here and cuts through
  this trace, and possibly this trace and maybe  into this one.
  So, we just need to investigate that and see  what we need to bridge out there.
  Since this crack might be hard to see for  some of you, I thought I'd get the magnifying
  glass out and let you see a bit more closeup  what we're dealing with here.
  And I created this little diagram so you could  see exactly where the crack is and how much
  of the board it covers.
  As bad as this looks, it doesn't actually  cross that many traces so, this could have
  been a lot worse.
  OK, so the first two that we're going to  tackle are this one right here, which we can
  actually, if you get into it with the magnifying  glass you can see that there's a crack right
  through the middle of that hole, but all we  need to do is reflow that joint to make it
  whole.
  This one here, though, we need to get in here  and scrape away some of the solder mask on
  either side of this crack, so that we can  make a bridge across the crack.
  I'm using a very high tech tool here, its  called my pocket knife.
  I just want to expose enough copper here that  we can do that bridge.
  Next, DJ added a little solder to the copper  he had exposed, then he bent a paperclip to
  an approximate size and soldered it right  across the crack.
  Then he just chopped off the extra paper clip,  and the joint is repaired.
  OK, so then I just want to make sure that  this joint that we just made has continuity
  so I'll go here and the meter says yes.
  After that, we worked to re-assemble the monitor,  which took about 20 minutes.
  The whole time we were crossing our fingers  and hoping this fixed everything.
  We had to cut several zip ties, so we replaced  those with brand new zip ties.
  We also used some hot glue to fill in that  area we had to cut away before.
  Well, let's see if we let the smoke out  or if it blows up or something like that.
  We've got it all put back together again.
  Hoping for the best.
  Hey, I hear high voltage.
  Look at that!
  I'm going to poke at it now.
  Still got high voltage.
  Alright!
  I'm calling that one fixed!
  OK, it's been a few hours, so time to check  on the keyboard!
  I've got to admit I can't see any difference,  but it's hard to say until I rinse it off
  and take it inside to compare with the PCjr.
  So here it is after rinsing and comparing  it with the other half of the keyboard, I
  can't actually see any color difference.
  So, I think this is the original color after  all.
  That being the case, it is time to put the  keys back in.
  Fortunately, I do have a picture I took of  the keyboard before I started, which will
  make it easier to re-assmble.
  Popping keys back into a freshly cleaned keyboard  is always extremely satisfying.
  It's like you just bicycled up a really  tall hill and now you are coasting back down
  the other side.
  And here's the freshly cleaned rubber mat.
  And the logic board.
  And the back piece.
  And here's the finished keyboard.
  The color may not have changed, but it looks  a hundred times cleaner now!
  It looks almost brand new, except for one  problem, which is that missing badge.
  So I had an idea of how to solve this.
  Looking at the PCjr itself, I assumed the  badge probably matched this one.
  They are the same size.
  I think I can use my brother label maker to  print a replacement.
  I always keep several different colors in  stock for this sort of thing.
  I think I'll use the black text on clear  background.
  So, I'll pop this one into the label maker,  then I made a quick little design here.
  Since the labels aren't wide enough, I made  it as two separate parts.
  And now to print it.
  Of course to make this look right, I want  to stick the labels onto this aluminum tape.
  So I first had to cut a square that fit perfectly  in the hole.
  And once I was sure it fit, then I peeled  the backing off the label like so, and I think
  you can see where I'm going with this.
  I just stuck this right to the aluminum.
  And here's the finished badge.
  Granted, this is much thinner than the original  badge.
  But I think it will still stand up to scrutiny  in most cases.
  And there we have it.
  It's obviously not perfect, but it was easy  to make and I would imagine the average person
  would never notice that it wasn't the original.
  I went to the hardware store to find rubber  feet, but it's hard to know which one will
  fit.
  As I'm always needing rubber feet in various  sizes and I'm just about out of them anyway,
  I just bought one of each package.
  I'll likely use these at some point in the  coming years.
  This keyboard uses unusually small rubber  feet.
  I tried the smallest one I got and it was  still too large.
  What I'll do is order some smaller ones  on eBay, but for the moment I can just cut
  these down to size and they should fit just  fine.
  And so yeah, there you go.
  Fits fine now.
  However, there's still a problem in that  the new foot is slightly taller than the rest,
  especially this one on the opposite end.
  So what I'll do is go ahead and pull that  one out too, and replace it with another of
  the same kind.
  And then I'll turn it over and test it out.
  Yep, it is not wobbly anymore.
  As for the computer, it still needed to be  cleaned, but it was mostly just scuffs and
  dirt, so I just used my usual methods to clean  it up.
  Once I was done cleaning, I thought I'd  better go ahead and do some disk drive maintenance.
  I used some alcohol and cleaned the disk drive  heads.
  This one is double sided, so you have to clean  top and bottom.
  Then I used some lithium grease on all of  the moving parts, especially the rails.
  And now it's time for a final test.
  The computer looks good.
  And it appears to be working properly as well.
  This restoration project has been a complete  success, unlike some of my earlier projects.
  All right guys, I hope you enjoyed this episode  on restoring the PC Junior.
  This is one of my more successful restoration  projects.
  And I always want to give a thanks out to  DJ for helping me with this monitor.
  There is something that I want to mention,  though.
  First of all, this video was not planned,  I just needed to get it done because I am
  planning on doing an entire documentary on  the PC Junior here relatively soon.
  So, I just needed to get it working.
  The other thing that I wanted to mention is  because I am using a CRT display in this video,
  I just thought this would be a good opportunity  to mention a problem that pops up from time
  to time.
  I always get comments down in my videos saying,  "Hey David, can't you remove that terrible
  high pitched whine noise that I hear, it hurts  my ears."
  Well, here's the thing.
  Actually, I do.
  In fact, 95% of the time I get that whine  removed, but 5% of the time I don't.
  And you're hearing the 5% of the time that  I've missed it.
  The reason I missed it is because my 42 year  old ears simply can't hear the sound, at
  all.
  Now, I know what the sound sounds like because  I remember hearing it when I was younger.
  So, what I have to do is I have to look for  any scene where I'm using a CRT and then
  I can actually dump a high pitched filter  in there in the editing process to hopefully
  reduce or remove that sound.
  But, here's the thing.
  When I'm done with a video, I typically  watch it two or three times looking for spelling
  mistakes, or you know anything wrong with  like where something needs color correction
  or something like that and I can see those  things most of the time when I'm reviewing
  the video.
  But, I literally can't hear the high pitched  whine so if I've missed it then I've just
  missed it.
  So, all I can do is apologize for that, hopefully  I got it all in this video, I tried.
  I went back like three times and verified  every clip that has a CRT in it.
  I put the filter on there.
  Sometimes the filter doesn't always work  too.
  I'm not sure why, but I've been told sometimes  they can still hear it even when I know I've
  put the filter on there.
  So, I hope I got it all out, maybe I didn't.
  Anyway, I'll apologize for it in advance.
  And, I look forward to presenting the full  documentary on this computer.
  It's a really fascinating piece of computer  history.
  Until then, stick around and thanks for watching!
     
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