I've been Coleco'd

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rubber_jonnie
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Re: I've been Coleco'd

Post by rubber_jonnie »

OK then, so one more RAM IC replaced and back to normal:

IMG20240930141256.jpg
IMG20240930141256.jpg (353.42 KiB) Viewed 141 times

Once again spotted using the thermal camera as it had gone cold. Getting quite tempted to replace the lot now, but I'll leave it doing a burn in this afternoon and see what transpires.

EDIT: Audio also works just fine.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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PhilC
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Re: I've been Coleco'd

Post by PhilC »

Nice spot there RJ, we all usually concentrate on ram chips getting too hot, so I'll have to remember that one.
If it ain't broke, test it to Destruction.
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rubber_jonnie
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Re: I've been Coleco'd

Post by rubber_jonnie »

PhilC wrote: Mon Sep 30, 2024 4:26 pm Nice spot there RJ, we all usually concentrate on ram chips getting too hot, so I'll have to remember that one.
What's interesting is that the 2nd one that died also went cold. Not as cold as the first one, but colder than the rest for sure.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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stephen_usher
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Re: I've been Coleco'd

Post by stephen_usher »

The bias voltages probably burnt something out so there was no more current going through. 4116 chips are really sensitive to the timing of the bias voltages coming up. They also seem to die if left unused for a long time, dying after seconds or minutes. The ones in the TI99/4A that passed through my hands displayed this... The machine worked ine for about 5 seconds and then one and later another 4116 just stopped working.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
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HigashiJun
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Re: I've been Coleco'd

Post by HigashiJun »

So far so good !

:D
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rubber_jonnie
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Re: I've been Coleco'd

Post by rubber_jonnie »

stephen_usher wrote: Mon Sep 30, 2024 7:13 pm The bias voltages probably burnt something out so there was no more current going through. 4116 chips are really sensitive to the timing of the bias voltages coming up. They also seem to die if left unused for a long time, dying after seconds or minutes. The ones in the TI99/4A that passed through my hands displayed this... The machine worked ine for about 5 seconds and then one and later another 4116 just stopped working.
Have to agree with you, and in fact at power on this morning I'm seeing some more issues:

IMG20241001090230.jpg
IMG20241001090230.jpg (148.72 KiB) Viewed 75 times

The writing, AFAIK, should all be black, at least it was yesterday, and it randomly changes when you reset or power cycle. I think I'll just go ahead and replace the rest of the 4116's, I think they are past their best.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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rubber_jonnie
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Re: I've been Coleco'd

Post by rubber_jonnie »

OK, so the RAM is all good now, at least I hope it is :) Even if it isn't, I have it all socketed now so swapping out will be a breeze.

I also managed to get the RF shields cleaned up and painted and I'm pretty happy with the results:

IMG20241001223810.jpg
IMG20241001223810.jpg (142.25 KiB) Viewed 50 times

So I can start to get things reassembled, though I may wait and sort out the video out first as whilst it isn't bad over RF to my LCD TV, it's not the best either.

Overall looking way better than it did though.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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HigashiJun
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Re: I've been Coleco'd

Post by HigashiJun »

:yay2:

Looks good.

Well done !
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rubber_jonnie
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Re: I've been Coleco'd

Post by rubber_jonnie »

HigashiJun wrote: Wed Oct 02, 2024 1:03 am :yay2:

Looks good.

Well done !
Thanks :)

Looks like the ColUSB power adapter has been processed in the export centre, fingers crossed it won't take too long to come.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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HigashiJun
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Location: Tokyo

Re: I've been Coleco'd

Post by HigashiJun »

And just hope it will solve some issues too.

8-)
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