Guess what's wrong with my TS1000

[monzamess]

Attached is a picture of the image my TS1000 (US NTSC) makes on a TV. You can see the bottom of the screen tears and gives a hint of a "K" cursor. Maybe. The computer is non-responsive to key presses.

This is my original TS1000 bought in 1983 when K-Mart was clearing them out for $50 USD (and the 16K RAM expansions were still $50 USD, had to save up for that). At some point along the way I attempted a composite mod by attaching wires to and RCA jack, plugging it into a monitor, and touching the wires to various points on the motherboard leading into the RF modulator. It actually worked, briefly. I think I screwed up the keyboard ribbons during the process which could explain the current non-responsive keyboard. Hard to remember; it was 33 years ago.

I would like to fix this one if possible. Already tried buying one on eBay and I'm 0-for-1 so far.

I know it's silly to diagnose a computer from one image *unless* it's something that's very common and (crossing fingers) easily fixed... I appreciate any advice.

my_ts1000.jpg (90.8 KiB) Viewed 3517 times

[dessony]

First, check for any wears, cracks or breaks on its ribbons connecting to the keyboard. If so, then try to get a new keyboard for the TS1000. You can try a RWAP software's website or a Sell My Retro's website.

Is an ULA bearing "2C210E" label?

May I suggest you try 1024MAK's excellent video amplifier circuit? I tried it on my TS1000 and TS1500. It worked very good!

Thanks,

DesSony

[Lardo Boffin]

Assuming the computer is basically working then you could also get one of these:-

http://www.sellmyretro.com/offer/detail ... -zx81-3712

I have fitted one to my TS1000.

[monzamess]

I removed my questionable "composite mod" and re-seated all the chips. The ULA is the 210. Of course I obliterated the keyboard cable in the process, to be expected. But otherwise, my childhood TS 1000 appears to be alive! Now to shop for keyboard and real composite mod and... and...

ts1000 lives.jpg

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[sirmorris]

Like!

[monzamess]

I spent at least two hours (I console myself thinking it was only two hours) building a replacement cable (of sorts) for the keyboard. It's in the foreground of the picture. I used solid core wire thinking it would make better contact, and it did... but it was so inflexible that it was nearly impossible to control and keep aligned. I also "designed" it to fit through the keyboard cable slot in the TS1000's case and of course it did not. In the end, a small section of the keyboard worked with this monstrosity and that was it.

Luckily there was just enough of the original keyboard cable left uncompromised to plug it into the motherboard, so this setup will have to do!

ts1000 crapboard.jpg

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[monzamess]

Ok, one last picture and I'll quit littering this board with pictures of my mess.

I received my ZXpand+ today and it's pretty cool.

Having something cool on my TS1000 meant I had it turned on longer than when I've just been troubleshooting it.

The result is that the screen starts to become corrupted as shown in the image after 20-30 minutes.

The horizontal lines are like static or "snow" and flicker around randomly. The effect goes away once the TS1000 is turned off and cools down.

I have experienced a similar screen degradation once before when the computer was on for about 30 minutes without the ZXpand connected, so I don't think it really has anything to do with the ZXpand.

Is this a sign of a bad ULA? Would a heatsink help it?

ts1000 screen bad.jpg (104.86 KiB) Viewed 3392 times

[1024MAK]

The modulator can be the cause of some video picture distortion.

I can't really tell from the photo you posted.

Mark

[Moggy]

Hi Monzamess.

I would guess this is heat related as a turn off and cool down temporarily cures it.

My views on heat sinking a chip in an enclosed environment with no air movement through the case are well known here and suffice to say I find it a redundant exercise.
But seeing as you are working "open chassis" so to say a heat sink may be useful as there is ambient air moving over it so as to remove heat from the sink.

I use two of my 81's open chassis and have a PC case fan blowing down on the gubbins to keep things cool.

Should it be a heat problem with the ULA than it could be indicative of it being on its last legs and if it cannot function correctly in an open air environment then frankly when its enclosed it may fail completely.

[monzamess]

I would guess this is heat related as a turn off and cool down temporarily cures it.

My views on heat sinking a chip in an enclosed environment with no air movement through the case are well known here and suffice to say I find it a redundant exercise.

My intention is to put the case back together once I solve the keyboard problem. I had the same concerns about heat but wanted to hear it from someone else.