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TRS-80 Model 12 Service Manual

pski

pski

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A unicorn arrived today! Up until now I wasn't sure if this actually existed, because I've been looking for it for a long time. Not sure if I'll scan it yet, because there is nothing in it that you won't find in the already available Tandy 6000 Service Manual. In fact, the 6000 manual incorporates this one almost exactly, word for word and diagram for diagram. But, still cool to see.

IMG_1587.jpg

Now, where to find the 16B Service Manual? The quest begins anew.
 
Another unicorn arrived today! The 16B Service Manual.

IMG_2962.jpgIMG_2963.jpg

The only significant difference from the existing scanned 6000 manual is that this one covers the operation and specs of the second version of the 6Mhz 68000 CPU board found in the 16B.

Will put it in the scan queue. But I can provide pics or single page scans of relevant information if needed. Just hit me up.
 
My "new" Model 12

My "new" Model 12

Hi Pete,

I just acquired a Model 12 from Germany. The unit has type number 26-4004 and serial number 0000638. History unknown.
Unfortunately the keyboard is missing and the case has some minor damage.
Also missing is the panel that covers the access to the optional cage. Mine has no card cage.
At first I tried to open it following the instructions in the Model 6000 manual.
I found out that there is a major difference: The front and the top cover are bolted together with 8~10 screws. This means that in addition to the 7 screws that fixate to cover, you also have to unscrew the 3 on the front.
Is this difference shown in the M12 manual?
Then, when lifting up the cover, you have to rotate the whole thing in such a way that you do not stretch the video cabling. (Or have somebody else disconnect the cables)

The first thing I discovered was that all the nut clips that hold the mounting screws where broken off. Major repair required. Has anybody tried to replace these pillars? Maybe 3D printing could recreate them?
The other interesting thing was the character ROM on the video card being labeled as "EUROPEAN CHAR.GEN.U9". So definately a machine prepared for the European market.
The inside of the machine looks clean.
Inspection of the power supply showed 3 capacitors in bad need of replacement (C1 0.22 uF, C2 0.1 uF an C9 0.01 uF).
That will be my first priority.

Regards,
LaserVision

EuropeanCharGenM12.jpgclipsBrokenOff.jpg
 
LaserVision said:
I found out that there is a major difference: The front and the top cover are bolted together with 8~10 screws. This means that in addition to the 7 screws that fixate to cover, you also have to unscrew the 3 on the front.
Is this difference shown in the M12 manual?
Then, when lifting up the cover, you have to rotate the whole thing in such a way that you do not stretch the video cabling. (Or have somebody else disconnect the cables)
Click to expand...

Yes, that is one difference we have identified since I first created this thread. In the Model 12/16B, the cover and bezel are once piece known as the Cover/Bezel Assembly (even though they appear to be 2 separate pieces they will not come apart easily by unscrewing as there seems to be an adhesive involved). In the 6000, these were broken into 2 separate assemblies to make maintenance easier: the Top Cover Assembly and the Bezel/CRT Assembly.

I need to get the 12 manual scanned.
 
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