Waz DAT ?

Sooo, a couple of days ago I heard a small snipped of a song on TV which I remembered that I liked a lot … then I remembered that I actually had a copy of it on tape … yes, TAPE.

Back in the olden days we used to record music on magnetic tape, but I ain’t taking about yrrr typical compact cassette, I’m talking about Digital Audio Tape. Sony introduced DAT in 1987 … it recorded 16-bit digital on magnetic tape and supported recording program numbers and ID’s, which is why it was most common in recording studios. Back in my yuut I had much money, and being a tech geek, I thought paying $600 (I was able to get it at cost price, and it was the lowest consumer model) was great for a digital recorder.


Sooo, back to the story … I rummaged around my tapes and found it … Panic in Detroit, by David Bowie. Great !!! I popped it into my Sony DTC-750 DAT deck and created an MP3 on my MacBook. Hmm, since I am here, lets look for some other songs … and that’s when the problems appeared. It started with not pulling the tape back into the cassette (a DAT loading is like a VHS tape … hmm, not sure how many of you remember those either … the tape gets pulled out and wrapped to a helical scan drum), so when it was ejected it left the tape exposed and crinkled. I realized that there was a problem with the pickup spools not being engaged by the motor properly … or the motor is dying, as FF and RW are very sluggish !!

Well, since I don’t have any cameras that I need to work on (actually, that is a big lie as there are two cameras that need the seals replaced, but I am stalling on that job) I am going try to get this thing working.


I did some presearch on the web to see if this was common or if anyone else had documented taking this thing apart … and I was in luck.

It was not too difficult to get the main part out.



DSC03994Looking over the gears, I did not see anything obviously broken.

Stuff turned, moved …

Hmmm, so I put it back together and seated it back in … powered it up, and started watching the mechanisms as it loaded, played, reverse play … ah, there seems to be a problem here.

When the reverse play is engaged, the drive motor does not move … so this causes the pickup spool not to turn … which in turn causes the tape to turn into a pile of spagetti.
DSC03993 Well, the motor does turn and the belt looks ok … so I am guesing the motor is dying (the thing is 30 years old).

I figured that it probably was not worth it to get a replacement part … so I just sprayed some Lighter Fluid into the openeings, and hope for the best. I thought it would clean out any gunge (even though it would flush any lubricant on any bearings).

Letting it dry, I put it back together and exersized it by FF and RW a tape over and over … well, it appears my bet paid off … now I can sit back, listen, and relive the 80’s.


Did some baking today …

Couple of weeks ago my old ASUS ROG G60Vx laptop started showing vertical red lines after booting into the Windows desktop … ok, lets try getting into the BIOS but I could not read anything on the screen … hmm, looks like the graphics chip is going kaputs. Time to look for a replacement video card.

Hunting around I realized that a replacement card is not going to come so cheap. Ok, not really a problem as we have multiple Windows laptops and MacBooks in our household.

I really don’t like disposing of things that could be brought back to life … so today I decided to try the old temp bake job. Typically the cause of graphics card failure is the soldering contacts between the GPU and the PCB. The technique of baking is to re-flow the solder and bond it back together.

I pulled out the PCIe graphics card, and preheated the oven. Solder typically has a melting point of 188C/370F, so I set it to 375F. I wrapped some tin foil to cover the surrounding parts, and also make some legs to elevate it. I placed this on a pizza plate ,that has holes in it, and left it in for 10min … then left it to cool with the door open. I noticed on the web about discussions concerning fumes from the PCB board … since my GPU is on a small board I was not too concerned.

Ok, so the baking is done … clean off the old thermal paste … get rid of some dust … boot up, and hope for the best … BONUS !!! I have a BIOS screen I can read, and no artifacts showing when I booted up into Windows.

Now for all of you others thinking of doing this … this is just a temp job, the soldering will fail again at some point in time … or you can over-heat the board too much and damage other components.

Canon … Canonet QL17 G-III … shutter, well almost.

Hmm, sticky shutter … seems to be a common theme with older cameras, at least the ones the I get a hold of.

Tools: spanner wrench

DSC00512 Unlike the Olympus that I worked on previously, the front lens plate is secured by an outter locking ring that is unscrewed.

The inner ring can be removed if you need to get in between the front lens group … this will not get you closer to the shutter blades.




DSC00511Under neath is a plate that changes the amount of light hitting the exposure meter.










Ok here is where you will need the special tool … welllll I don’t got one, so I am stuck with only going this far.

I tried using a rubber friction tool, but this front group was really secured … probably never taken off before.

Not much access to anything here.

So, how did I free the shutter? As is common with many shutters, the rear lens cell can be unscrewed. This allowed me to access the blades, and get some fluid on it to loosen it up.







Summicron-M collapsible

I got a hold of a Leitz 5cm f/2 Summicron-M collapsible lens … one that was in really bad condition, which was the only way I could afford grabbing this type of lens. I have to say (and I knew for a long time) Leica M stuff is EXPENSIVE (I thought the LTM was over priced).

I did not do a complete dissasembly … like getting at the focus helicoid.


The lens is actually not that difficult to work on, but just requires a bit of pre-info … since you really don’t want to damage a Leitz.

The front element is very soft so it is noted on being very easy to scratch when cleaning. This one has heavy haze and fungus.





DSC00531To get to the aperture blades you can just unscrew the entire front group off.

Getting between the elements of this front group is something I did not even attempt to do.







DSC00532You can remove the rear cap section, but you have to do one thing first. There is a small screw in the side of the lens barrel, loosen that first

It is a brass screw, so watch out !!!







before using your spanner wrench to unscrew the rear retaining ring.










The collapsible lens rides on two slots, and the rear focus ring has two bearings inside it … so try not to loose them … and when putting it back together you have to line up the slots.

You can see the two bearings (the left one is missing in this shot).





Here is a picture of the end cap attached to show how the slot should line up.

The encap goes on after placing the focus ring on … so you will have to eye ball it.

Then screw the retaining ring back on with the spanner wrench without turning the end cap … then secure the side screw.

Cron the destroyer …

The Leitz 50mm lens went through many different iterations since 1924, starting with the Anastigmat designed by Max Berek … the Summar was the first of the f/2 line in 1932, then Summitar, then finally the Summicron.

The Ernst Leitz Wetzlar Summacron 50mm (5cm) f/2.0 first production M-mount started 1954. The Leica part name for the m-mount version is SOOIC-M (don’t ask me about that). 7 elements in 4 groups … that’s a lotta glass !!! The original version started as a collapsible, later 1956 they also producted a rigid body.

Early 50mm Summicron’s had lens elements, made by Chance Brothers & Co., that had thorium oxide in it … very low radioactivity and it eventually turned the lens little yellow/brown over time … they quickly switched over to their own lanthanum oxide formula.

Marco Cavina has a great website about Leica, though it is in Italian … but I don’t think you will have any problems finding reading matrial about anything Leica.

Now I am not a Leica person, I was caught offguard when people use the suffix to talk about various lenses … and this one being the Summacron 50mm (5cm) f/2.0, it was refered to as a cron. It appears that a Summacron refers to the f/2.0 aperture size ? … obviously I am a Leica newbie … so what do I really know.





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