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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

OK, so the transistor Q1 tests bad. Unfortunately the can is corroded just where the part number is so I can only just see that it ands in "2A" which isn't very useful as many transistor numbers end in this combination.

Also, the PCB of the power supply is crumby. It's unsually double sided but the vias seem to be made of cheese. Just putting the Hakko on the legs of the component long enough to melt the solder lifted the pads.
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.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

Loks like the transistor was a simple 2N2222A. I have some so I can try it.
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.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

Nope. No change. Oh well.

I'd better order a Meanwell RT-85B as a replacement.
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.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: General Stuff(tm)

Post by rubber_jonnie »

stephen_usher wrote: 03 Feb 2024 12:00 It needs the PSU's 12V to power the display. I could potentially lash up a luminance+sync->composite sync cable but far better to get the PSU working.

It's quite possible that it's the Zener. I'll have to see.

I've had to go into work this morning as the virtual infrastructure lost connectivity to the new storage, on which all the VMs reside. The two Dell 10Gb switches had both reverted to an older set of settings for some reason and lost the new VLAN configuration I set six months ago and definitely saved.
Sometimes I really dislike modern technology...
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: General Stuff(tm)

Post by rubber_jonnie »

stephen_usher wrote: 03 Feb 2024 19:40 Nope. No change. Oh well.

I'd better order a Meanwell RT-85B as a replacement.
Power supplies, my other nemesis. Thank god for Meanwell.
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: General Stuff(tm)

Post by PhilC »

I think I’d ditch the old PSU as well once the tracks started lifting.
If it ain't broke, test it to Destruction.
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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

PhilC wrote: 03 Feb 2024 22:32 I think I’d ditch the old PSU as well once the tracks started lifting.
Well, it's not the tracks as much as the vias dying. As I said, it's a two layer board, which is very unusual for a power supply.
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.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

Hmm... Looks like the "power good" detection circuit in the OPD monitor's power supply is on the blink now. Need to investigate.
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.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: General Stuff(tm)

Post by rubber_jonnie »

stephen_usher wrote: 04 Feb 2024 13:57 Hmm... Looks like the "power good" detection circuit in the OPD monitor's power supply is on the blink now. Need to investigate.
Ahh Damn...
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: General Stuff(tm)

Post by PhilC »

The joys of owning retro computers. Broken, then
Fixed, shortly followed by broken again.
If it ain't broke, test it to Destruction.

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