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TI-99/4a Modification Weekend.

mitsumi keyboard repair keyboard Reset Button Mod Tursis internal 32k mod

81 replies to this topic

#76 Sinphaltimus OFFLINE  

Sinphaltimus

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Posted Fri May 19, 2017 5:57 AM

 

No, you need to measure it out of circuit. Switch off the PEB, pull the resistor wires off those two pins you added, and measure across the resistor with it not connected to anything.

so when I set my multimeter to 2k ohms I get 0.10, when I set it to 200 ohm I get 10.0 - does that mean my resistor is 10 ohms and not 10k ohms? Or better yet, what does that mean? 



#77 Stuart OFFLINE  

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Posted Fri May 19, 2017 6:51 AM

Looks like 10 Ohms. Which is consistent with the pictures you've posted - a 10 Ohm resistor has colour bands brown-black-black-gold, and those last three bands seem to correspond with what's left on the resistor.



#78 Sinphaltimus OFFLINE  

Sinphaltimus

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Posted Fri May 19, 2017 7:04 AM

OK, looks like I'll have to order some spares. Thanks for your help.



#79 Sinphaltimus OFFLINE  

Sinphaltimus

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Posted Fri May 19, 2017 8:27 AM

So after measuring my resistor and ordering some spares I broke the weak connection in the corner of the board reinstalling it.

 

Attached File  20170519_093442.jpg   473.26KB   0 downloads

 

So I had to locate a new place to resolder a connection. I spotted an unused solder hole just to the left as I followed the trace.

 

Attached File  20170519_093707.jpg   642.22KB   0 downloads

 

I heated up a pin to push through the solder then clamped it into place.

 

Attached File  20170519_095104.jpg   493.86KB   0 downloads

 

Then some flux and solder - it's now secured better than before.

 

Attached File  20170519_095249.jpg   456.25KB   0 downloads

 

Now to understand what I'm up against. The solder point it on the back of the board, I am basically soldering blind - memorizing cell phone pictures to get my plan in place.

 

This is the top of the board after the work was done, the solder side is facing in towards the bottom of the PEB. 

 

Attached File  20170519_095325.jpg   449KB   0 downloads

 

Lo and behold. It lives! it hungers!
 

Attached File  20170519_100959.jpg   1MB   0 downloads


Edited by Sinphaltimus, Fri May 19, 2017 8:30 AM.


#80 digdugnate OFFLINE  

digdugnate

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Posted Fri May 19, 2017 10:06 AM

sweet!



#81 Sinphaltimus OFFLINE  

Sinphaltimus

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Posted Fri May 19, 2017 10:10 AM

In the middle of the PEB there are 2 switches. One RESET which is wired to a connector on the outside. It's waiting for me to modify the console with a reset header so I can hard reset the console when needed. The older console that used to have the header still does but I have my nano and other mods applied to that one.

The power switch is actually wired to my GoTek, it's the switch that loads the disk image after I select it with the two buttons on the GoTek. The displays are the GoTek image selection display and 3 temp probes for the PEB interface card, 32k card and disk controller card.



#82 Sinphaltimus OFFLINE  

Sinphaltimus

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Posted Sat Jun 24, 2017 9:15 AM

Here's the kit.

Attached File  20170624_103438.jpg   570.8KB   0 downloads

However; I lack the skills and possibly the tools to craft such tiny elements. I guess ilk have to find someone to assembly it for me. Or sell it and buy the preassembled kit.

Attached File  20170624_110311.jpg   530.86KB   0 downloads

Edited by Sinphaltimus, Sat Jun 24, 2017 9:16 AM.






Also tagged with one or more of these keywords: mitsumi keyboard repair, keyboard, Reset Button, Mod, Tursis internal 32k mod

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