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Tandy 3800 HD Repair/Restoration

.... and yet I have an HP EXTERNAL SATA drive that has that cap...

Okay...

JUST FOR YOU,
I have destroyed a corner of one of the other power supplies, removed the screw, and have taken some pics of it...
I hope they are useful.


picture008.jpgpicture009.jpgpicture010.jpgpicture011.jpg

Taken with my Surface RT... :p
 
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It is one weird screw, that's for sure. Out of the 100+ screw types I looked at online, the only one that appears to be a likely candidate:

http://www.instructables.com/id/Whe...r/step93/Tamperproof-System-Zeroreg-Security/

Here is a better pic:

http://www.securityfasteners.net/co...ge/product/System_Zero__Sec_4c8254aa5a80f.png

If so, we're probably boned, since it is a proprietary screw

It's a machine screw, right? So that would make it, probably, an M3, M2.5, or M2.

Leeb, can you measure the diameter of the entire head of the screw?
 
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That security screw looks similar to the one's used
in old Nintendo carts or similar. Try looking for security
tools on ebay to disassemble video consoles/carts or
electronics.
 

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Im going to limb-climb and say yes...
It looks slightly wider than the belt(s) Ive been putting on the floppies...

:D
 
Im going to limb-climb and say yes...
It looks slightly wider than the belt(s) Ive been putting on the floppies...

:D

Yeah, I think it will be close enough, the ones in the power supplies are about one size larger than the ones in an SNES cartridge. As such, if the 3.8 is too small, the 4.5 should work. Apparently what people have been calling "gamebit" is actually a System Zero tamperproof security bit...
 
'Just the right' belt...

'Just the right' belt...

Finally got the shipment of 10 floppy belts today. As it just so happens I had kept a 'bad' one lying around, and the new one does seem a tad shorter, so I suspect that they ARE going to be good...
I will open up one of the waiting drives and see how well it fits.

**fingerscrossed.jpg**

:D
 
I look forward to hearing how they work.

If you sell any of those you have, I'll probably buy one. I would really like to get that second drive up and running again, or least even see if it's running. I don't know if it has any more issues other than a bad belt since the belt itself is a dead end to functionality.

At least I was able to reformat the 5 out of 6 Windows 3.1 disks (Tandy version) I had into useable blank floppies. Gotta love a set of disks with one missing disk, pretty much good for nothing except as blanks.
 
I'd be happy to sell you one, but be aware that I intend to make 'a few pennies' on those I do sell!
(NOT $25 worth... that is outright theft...)

It seems to fit very well, but it will be a while before I can test it...
The mainboard side of the ribbon cable is trying to lose its conductors... and until I figger out how to reglue them I cant run it.

... unless I take a control board off a different drive to spin it up with... :rolleyes:

Might do just that. Will report back once it has been tested.
:D
 
Alright finally could get into that 1500 you gave me Paralel!
What was rattling around was one of these.
UPA1523H_NEC_IC.jpg
I have NO idea how the leads broke but they did and it was loose in the case.
I will have to look for either another one on one of the 100 random scrap circuit boards I have or try to solder it back on.
But right now I have two Tandys no hard drives and a floppy drive I still haven't tested so heh it may be rough to see if I can get it working but I should be able to at least boot off a DOS floppy right? If the drive works that is!
So yea this is odd to how that chip broke off the board just at the leads but it should be saveable... Lets hope!
 
That IC does NOT belong on the board!!!!

Dunno where it came from, but MY 1500 has NO SUCH PART installed ANYWHERE!!!



:huh:

EDIT: Well, Im VERY SURE it does not belong...
BUT,
to ensure accuracy, I will check my 1500 tonite after work...

Joy. Another Tandy to disassemble! :p

:D
 
Well it did not look exactly like that but it reads as follows.
NEC
UPA1523H K049A
It was to the right of the power plug...
It looks like it broke off from there and it fits so...
I am unsure to as why this one has it and yours doesn't...
 
Like I said... lemme take a look to confirm...

... before I start chewing on my foot again.:D


Oh... can you snap a pic of the spot you believe it came from?
... something to compare to mine when I get home... :)
 
Alright... Also its amazing the difference in the boards from the 1500 and the 3800...
I never researched the 1500 and or its specs... Care to clear up this for me?
Which one is newer and such... specs of say processor speed and such? I could look it up myself but if you are wiling to spurt out what you know that'd be great!
 
Okay... here it is...

1500 HD (250-3506) Specifications Faxback Doc. # 1901

Dimensions: 12 3/16 x 1 5/8 x 10"
Weight: 5.99 lbs. w/battery
Processor: uPS70108-10 (V20)NEC
CPU Speed: 10 MHz
# of Slots: (1) Modem Slot
Std. Memory: 640K
OP Sys: MS-DOS
Max. Memory: 1.64 Mb
Video: LCD (CGA) 640x200, Full Backlight
Power Supply: 120 VAC 60 Hz DC Output: 9.5 VDC 2.1A
Keyboard: 84 Key
Std. Ports: Serial-(DB-9)
Math Co.: N/A
Parallel-(DB-25)
Floppy: 3.5" High Density 1.44 meg

CURRENT BIOS ROM Version: 02.52.00 Utilities Version: N/A

Yep... copypasta. :p

If, for some reason there is ANY doubt... the 3800 is newer. :D
 
That's what was rattling around in the case? According to the datasheet for a similar part number, it's a "Compound Field Effect Power Transistor". So, it's apparently part of the power regulation subsystem.
 
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