T/S 1000 help.

[Tupin]

Okay, so I got the AC adapter for my Timex Sinclair 1000 today, in the form of a 2600 adapter. I hooked it all up, turned it to channel 3, and plugged it in. I was encountered with snow, and the screen eventually turned up. However, it was not correctly colored, (black and gray, not greenish-blue and black) and sometimes it would fade away. The keys would not respond.

Is it a problem with the TV, the hookups, or the computer?

[channelmaniac]

The TS1000 was black & white. You'll end up with a single cursor at the bottom left corner of the screen.

It's common for the mylar keyboard leads to split and break which renders the keyboard unusable.

[Tupin]

So, should I open it up and make sure everything looks good and not broken?

I've always seen screenshots in green and black, not b/w.

[Tupin]

I opened it up, and I think I found the problem. A piece has appears to have fallen off, and I'm going to solder it back on.

http://i186.photobucket.com/albums/x28/TUPPYLUVER95/IMG_2322.jpg

[Tupin]

Still have no idea what could be wrong after soldering it and checking all the points on the board, but I don't know what else I can do.

I've never seen that metal piece in any of the pictures I've seen of it, but it has a voltage regulator on it.

[channelmaniac]

That's normal to have that piece.

[Tupin]

Hm, good. You know, as a passing thought, I was thinking that it was the Portuguese version with the PAL RF modulator. After all, it does say "Made in Portugal" on all parts of the computer.

Plus, the board has "SINCLAIR ZX81" on it.

[gokugohandave]

my timex has a blue screen, dont ask it just does.

[Tupin]

my timex has a blue screen, dont ask it just does.
Like I said, I think it's the Portuguese version because it doesn't work on my NTSC TV.

[Tupin]

Come to think of it, the ultimate evidence that it's a PAL unit is that instead of Channel 3 and 4, it has Channel 2 and Channel 3.

Any idea about what I can do to get this running, if anything? I can post pics of the board, if it's needed.

[gokugohandave]

Mine says made in portugal and has channel two and three. So they both might be pals, but ive never had a problem with getting it running.

[Tupin]

Here, I'll post a picture of the inside of the board. Excuse the blurry pic, but you can make out what the chips say.

http://i186.photobucket.com/albums/x28/TUPPYLUVER95/IMG_2347.jpg

Why that sticker is on there, I have no idea. That Toshiba chip actually looks like it's too small for the connection it's made to. Notice the board says "SINCLAIR ZX-81".

[Jimmy Yakapucci]

The fact that the board says Sinclair ZX-81 is not surprising. That is what the product was called before Sinclair teamed up with Timex to bring this to the "masses". I am sure that they just built the new versions with the boards that they already had on hand.

JY

[Tupin]

The fact that the board says Sinclair ZX-81 is not surprising. That is what the product was called before Sinclair teamed up with Timex to bring this to the "masses". I am sure that they just built the new versions with the boards that they already had on hand.

JY
Yeah, I think this might be an early version or something.

Is there any way I can test to make sure what's wrong?

[channelmaniac]

If R31, R32, and the Channel Select switch is installed then it's the US model.

Check for +5v out of the regulator IC. If you don't have that then the AC adapter polarity is wrong or the regulator is bad.

If you do have that then the only thing you can do is to replace the chips one by one to see which one is bad. There really isn't much more troubleshooting on such a simple system.

[Tupin]

Yeah, this is an American model, I guess.

I guess I'll need to get a multimeter, and measure the output in volts. Where exactly do I measure it from?

[gokugohandave]

If its a three legged regulator, with the system on,change the setting to 20vdc, looking at the regulator with the writing facing you place the positive on the third leg on the right, and the negative on the middle leg (ground) It should read 5v. If not place the positve on the left leg (leaving the negative on ground) and it should read 9v. If you dont get 9 its your power supply or the connection. If you do get nine but not 5 its the regulator, if you dont get either its not turned on or it could be the joint to the left leg ,the power adapter, or the power jack on the system.

[Tupin]

If its a three legged regulator, with the system on,change the setting to 20vdc, looking at the regulator with the writing facing you place the positive on the third leg on the right, and the negative on the middle leg (ground) It should read 5v. If not place the positve on the left leg (leaving the negative on ground) and it should read 9v. If you dont get 9 its your power supply or the connection. If you do get nine but not 5 its the regulator, if you dont get either its not turned on or it could be the joint to the left leg ,the power adapter, or the power jack on the system.
Thank you so much, now I just need to get a multimeter....

[Tupin]

Finally got around to testing it, now I'm even more confused...

I got around 5v with the positive on the third leg and the negative on ground, and I got around 9v with positive on the first leg and negative on ground.

Does it matter that I'm using a new-style CO1653 2600 power adapter rather than an old-style CO10472?

[Jimmy Yakapucci]

Finally got around to testing it, now I'm even more confused...

I got around 5v with the positive on the third leg and the negative on ground, and I got around 9v with positive on the first leg and negative on ground.


What you got sounds right for a working regulator, 9 volts in on the left leg and 5 volts out on the right leg. Sounds like your problem lies deeper within the unit.

JY

[Tupin]

One of the chips looks like it was installed weird, like it's too small for the mount it was soldered into, but that's probably normal.

[icbrkr]

If it makes you feel any better (and it won't), every Timex Sinclair 1000 and 1500 I've gotten over the last 10 years have been dead in pretty much the same fashion. That's about 12 of them so far.

[Tupin]

Thanks.

Who knew such a small computer (both internally and externally) could have such a high failure rate?

[channelmaniac]

I'll happily take dead ones. ;)