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Another C-100F resto

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#1 caution

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Posted 21 September 2018 - 09:43 PM

This crusty beast has been waiting for over three years for its second chance on life. Finally!

The description mentioned that it was "totally rusted and beaten up... Buttons beaten up (consider them non-functional) ... Too much rusty and need heavy cleaning. Volume knob Need to be steady at some level to get output from both speakers."

I don't know about the busted up part, because it cleaned up really nice. I'll break down the problems by area.

Back panel:
Very dusty and dirty, and likely a smokers box with all the yellow nastiness on it. One of the aerials (and its retention tab) was broken, and the felt along the edges was starting to detach in places. Other than that, the back is free of any cracks or missing chunks, and no visible scratches, just some minor scuffs and paint marks.

The water damage was mainly limited to the lower front, but the main control panel trim is all pretty splotchy from corrosion too, and detaching in places. The bottom of the rims and crash bars have misssing/bubbling/flaking chrome and lots of blemishes and yellow gunk that took forever to remove. The LED meters are in better shape, but still have minor pitting. One of them had a chunk busted off.

The tape tray was missing the spring, the rear foam cushions, the guidepin was busted off, the trim was mangled and falling off, and there was a big crack on the left section of the bottom.

The tape door was missing the main spring, as well as the two springs for the door alignment piece, which was also broken into four pieces and missing the entire top edge and part of one side. The sticker behind the cassette window was destroyed.

Dial window cracked beyond repair.

The battery compartment and door were like new. Probably the cleanest part of the box. The paper sticker and coils were pristine, I don't think anyone ever used batteries on it.

The tweeters were completely dead, and the mids both had small holes punched in them, one of them with a badly dented dome. The full range drivers were intact but had been wet at one point, and very faded.

The lower deck trim, although corroded, was used on my other C100F restore, where I didn't even have a trim. So this box will get a new one I'm making.

The upper deck's direction arrow decals were scratched on the back side.

The tweeter chrome was all but gone.

All knobs and buttons needed a thorough scrubbing with a toothbrush to remove the yellow sheen on them, and although they do suffer from corrosion they don't look horrible.

The dial bulb was burned out.

The upper deck was very misaligned, in need of a new belt, and had a very dirty head switch.

The lower deck's belts had turned to goo (but not the counter belt, they never do) and the switches were very dirty. The read head is extremely corroded/pitted, and sounds muddled even at good alignment.

The beat cancel switch was fine, but I swapped it with one from my other C100F resto, which had melt marks on the tip. So, I have that one on this box now.

Most pots, switches and jacks suffered from some amount of crackling or corrosion.

FM stereo did not work.







#2 Fatdog

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Posted 21 September 2018 - 11:41 PM

This is going to be an amazing journey - I just know it!


:yes: :popcorn:


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Posted 22 September 2018 - 12:18 AM

Yup, looking forward to this one

#4 Northerner

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Posted 22 September 2018 - 01:16 AM

Needs a good bath :-)

#5 caution

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Posted 22 September 2018 - 02:54 AM

Well I hope your snacks are ready and plentiful because I'm about to bust out almost 100 pics!

This took almost six weeks off and on, and I didn't do a few other things I wanted like a recap, retrobrite, and light for the needles. I also didn't paint the case. I considered doing a hydrodip or just a new coat but I want to take it around and not care about small scuffs and such.

Extra special thanks to trippy for painting the grills for me, it made all the difference in the world. Thanks again bro! Also thanks to Dr. Dave for letting go of a set of chrome bars for the LED VU meters.

This thing had so much nasty stuff coated on it, but it finally all came off. If the surface was flat enough, you could scrape the stuff off in small flakes, but it was a lot safer to scrub it with a soapy soft brush for a while.








The first thing I worked on was the beat cancel switch. After not finding a close enough match on my stash of switches, I visited a surplus store and found a really close match. I sawed the tip piece off the sacrificial switch and filed down the sides to match the width, cut off the damaged part on the switch, made sure each surface was flat, and welded them with solvent. I didn't spent a lot of time filing it down to the exact length of the original, so it sticks out a tad more, but not much.









The rest of the pots and switches were not damaged, but were all taken apart for a deep clean and some Deoxit. After fixing the beat cancel switch, ten pots and switches were overhauled. In order below: upper deck head switch, phono/line-in switch, record bar, stereo mode switch, loudness switch, mode selector switch, the four main pots and some closeups of the balance pot getting some Deoxit D100L.


I forgot to mention - I tried using toothpaste and an old toothbrush to get the patina off of the switches and it worked better than anything else I had - just enough grit to bring back a nice shine. And they smelled minty fresh afterwards :-D
















#6 Stuzy

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Posted 22 September 2018 - 03:35 AM


#7 caution

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Posted 22 September 2018 - 03:52 AM

The next task were the decks. The first order of business was to install some jumper plugs for a couple wires so I could detach it. As it turns out, the decks were in pretty nice shape and just a little dirty. The worst hit was the lower deck's head, which will need to be replaced it's so damaged.

I used a needle dropper bottle to refresh all the leaf switches, cleaned the rollers and heads, aligned and locked the head screws, lubricated a few spots, removed the upper deck's head switch for a deep dlean, and went through a ton of Q-Tips and isopropyl removing the old belt goop. And just as a precaution I installed a centering washer to the tape run shaft, to make sure it doesn't add any unnecessary load on the counter belt later on in life.








The LED bar only had an issue with one segment, so I initially began to replace the bad one, but realized that the replacements were in about the same condition, so I just swapped one of them into place and glued it. I also had a small issue with the LED covers for the upper deck's direction indicators, but a little touching up with red and black markers did the trick.





I managed to score a window off ebay that was in really nice condition except for a pink mark left by what I'm thinking was nail polish or a marker with solvents, because nothing would remove it and the plastic had warped a tiny bit around the edges of the mark. A lot of rubbing with a pretty fine grit sandpaper took it out eventually and although I tried to work up the fineness scale with the micromesh pads, I could never get past one of the last couple of pads without ending up with un-removable scratches from the last grade. Looks good enough though anyway, where it began to give me problems.





The lack of stereo reception led me to check the adjustment pot right away, and it was not reading anything across the ends of it. I swapped it out with one from my stash and it started working fine again.



The dial guide was pretty nasty with all the dust and debris the grease had accumulated over the years, so I cleaned it all out and added some SuperLube.




I used my Silhouette Cameo to cut a set of tweeter trim decals on chrome-plated mylar. You can see the difference as I stuck them on. Some areas were completely missing the chrome paint and you could see the original silver paint coat underneath.




The control panel trim is not the best but it will do for now, so I glued down the detached areas.



After everything was done, I had to reroute all the wires and glue them back into place, with lots of temporary duct tape to keep wires pinned down as the glue sets and cures.


#8 metalhandbag

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Posted 22 September 2018 - 07:19 AM

Quality work .

#9 MyOhMy

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Posted 22 September 2018 - 07:26 AM

Dear, dear me what a state - and a half!  There's such a monumental task ahead butI can't help feeling that this will be an overriding success at every turn to the point a Masterpiece is to be presented to us.  One thing that I always look forward to on these projects is the level of detail captured explained as it makes the whole story much more interesting, provides for a context regarding the intricacies involved, allows us to share the strife as well as see ingenious solutions to some very awkward problems and.................will keep me on the edge of my seat - and out of mischeif - for the duration.


I'm rootin' for ya!  :thumbsup:



#10 Fatdog

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Posted 22 September 2018 - 09:28 AM

I was hoping to see at least one pic of a "Full Patron".  :-/   But, this thread is becoming the stuff of legends!!  :bow: :thumbsup:

#11 caution

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Posted 22 September 2018 - 10:32 AM

The speakers were pretty nasty but after a good careful and gentle brushing and cleaning, I blackened the cones and they looked pretty darn nice. The mids sound fine after a patch job did the trick, but unfortunately I was unable to pull the dome out completely, although it's better than it originally was. I thought about replacing them but couldn't find anything in my stash close enough, so I decided to just repair them since it was minor.

The Dayton tweeters soldered into place perfectly. I discovered that if I carefully twist the speaker terminals 90 degrees, snip off the inner section of the tip, and bend them inward a smidge, they drop right through the holes the original tweeter leads fed through without me having to carve away some of the plastic. A little glue around the edge and they went right in. Unfortunately it doesn't look like these are for sale anymore, but they are a fantastic replacement for these blasters.

Since the new tweeters actually have an impedance as opposed to the old ones, I had to add a crossover cap. I chose 2.2uF and replaced the stock 4.7uF cap on the mid to a 10uF, both of them non-polarized electrolytics.













I've already done a few of these dial bulb replacement boards using LEDs, but I always used resistors tied directly to 15V. This time I decided to try using a voltage regulator. I tried 6, 9 and 12V, but I ended up going with 6V because its input range, 8V-21V, covers wall-power levels all the way down to weak batteries, with the idea that it will take a lot of bass on low batteries before they start to blink. I used 560-ohm half-watt resistors, so if I chose to, I could use a 9V regulator, but it looks bright enough at 6V and probably will be more stable, and after an hour of use the regulator does not get warm.














#12 caution

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Posted 22 September 2018 - 11:14 AM

Next up was the tray, which was in need of a new guide pin and spring. I sifted through my stash of springs to find a close match and bent it into shape, using the original from my other box as a guide.

For the guide pin, I did another plate that glues to the back and holds a screw the acts as the guide pin. I bent a flange just as deep as the original ledge on the back of the tray, and then filed off the old ledge and glued it into place. I used a dremel to grind down the screw head to be 3mm like the original pin, and added solder to the tip so that the Phillips head edges wouldn't grind away the plastic on the cam. A little work with a couple of pliers to offset it to align more with the original position of the pin and we have a winner!

Instead of replacing the original foam pads, I glued a spring on the back of the new guide pin plate to give a more consistent back-force when it's pushed all the way in, to keep it closed more securely.

I also used my cutting machine to make a lining for the inside, which uses a custom vinyl pattern I found online a few years ago.












The door frame was a little more work than I expected, but it was a critical part that was worth it. I found some pieces of ABS from my stash of plastic parts and carved them into shape based on the good one on my other C100F.

I decided that I would weld the triangular piece into place first before Dremeling out the channels for the end of the spring. One end of the top bar woud not weld securely due to lack of a flat surface on the original frame, so I used some JB Weld PlastiWeld, and also applied a couple of drops of it to the internal corners of the bottom legs that the cassette rests on, to give the weld a little more strength.

I also found a couple of close matches in my spring stash and bent/cut to shape following ones on my other C100F.

Once it was all dried and carved into shape, it fell right into place on the first try and works great.












And, all done!









#13 MyOhMy

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Posted 22 September 2018 - 12:03 PM

Wowser, wowser, wowser!  I can just imagine all the time it has taken to prepare every tiny detail with the utmost diligence & tenacity, all the highs and lows, long hours and frustrations and then the moments of euphoria when it comes together.  If there was a Boomboxery Medal of Distinction, you'd certainly get my vote for a resto such as this.  :yes:  :hooray:  :rock:

#14 Fatdog

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Posted 22 September 2018 - 12:47 PM

That's it.  I quit.  :bang:   There's no way that's the same boombox!  :nonono:








:lol: :lol: :lol:


Seriously though, you remind me of the old man who restored Woody in Toy Story 2.  You can tell that a lot of love went into the restoration of that poor Conion.


That checkerboard tray liner is F-R-E-S-H!


I need to get with Howie again and see if he can get me that Conion label so I can replicate the artwork.  There are lots of naked Conions out there.

#15 T-STER

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Posted 22 September 2018 - 01:52 PM

Woooow this is quite a resto. In fact this is way more than an average restoration and the results are stunning. I swear that cannot be the same box.

#16 Northerner

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Posted 22 September 2018 - 02:44 PM

That’s the way to do it!...excellent stuff!

#17 hardmen

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Posted 22 September 2018 - 08:19 PM

Awesome as usual!!!

#18 caution

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Posted 22 September 2018 - 09:17 PM

Needs a good bath :-)


How could I forget the obligatory bathtub pic?!?




Thanks for the compliments guys and MoMs  :-D 

#19 moshenskmz

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Posted 23 September 2018 - 08:31 PM

Wow man incredible! I need to get on this level

#20 Hisrudeness

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Posted 28 September 2018 - 03:52 AM

Another amazing resto. You’re definately the C100 master.

#21 Van Presence

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Posted 29 September 2018 - 04:03 PM

Wow that's a sweet job. I have had to make a couple of parts for mine but probably not as good as this level.
Any chance you can enlighten me on the size of the rear case screws? Mine has completely wrong screws. Cheers

#22 caution

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Posted 02 October 2018 - 02:27 AM

Thanks Rudey!
Yes, the screws. All of them use the larger phillips bit. The smallest one for the upper deck has a 6mm head with a JIS dot on it, so a JIS screwdriver is going to help avoid having to press down to prevent camout. You can't put a lot of downward force on it because it screws into the upper deck's bracket and can bend. The shaft is the same thickness as a #4 (2.8mm) screw, but they don't want to go in. I ended up finding one that was 2.74mm or so, and went in with a good bite because I think its thread style was a bit different. You can always drill out the hole on the deck bracket a tad to open it up for one you find that's just a bit too big. The original screw is 13.5mm long, but I used a 12mm screw with a 5.5mm head and it still worked.

Looking at the back, the upper left/upper right/lower right are 42.5mm. The other three along the bottom and the two in the center are 69.5, and the upper center one is 19.5mm. All of these nine have 8mm heads and 3.9mm thick shafts with that highly angled, deep thread for plastics.



#23 mellymelsr

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Posted 02 October 2018 - 02:12 PM

Great work once again Eric. A true genius in this hobby.

#24 Van Presence

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Posted 02 October 2018 - 11:49 PM

Looking at the back, the upper left/upper right/lower right are 42.5mm. The other three along the bottom and the two in the center are 69.5, and the upper center one is 19.5mm. All of these nine have 8mm heads and 3.9mm thick shafts with that highly angled, deep thread for plastics.


Ah mate, you're a champion. Exactly what I needed. Cheers

#25 jays

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Posted 10 October 2018 - 07:54 PM

houuuuuuuuu!!! that is what I call a great job... nice work

#26 caution

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Posted 18 November 2019 - 09:43 PM

Thanks jays!

#27 BoomboxLover48

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Posted 18 November 2019 - 11:12 PM

AMAZING!!!!!! :jawdrop:  :thumbsup: