Sporniket's log on hardware stuff

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DoG
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Re: Sporniket's log on hardware stuff

Post by DoG »

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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

Thank you ! Well, it is exactly like exxos has explained : the schematics is wrong, and on my STE the caps is wired according to this faulty schematics...

It's like the DMA lmc mix fault, so I will leave a note at this place.
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

Following the feedback of @DoG about the reversed C415, I disassembled again my STE, checked the voltage of said capacitor, removed it to install it in reverse position, and checked voltage afterward.

Nothing changed much on the display, as my capacitor must still be ok until now, at least it will slow down its wearing. I have yet to do the video ghosting fix and the PSU recap.

2021-08-27--ste-c415-fix.jpg
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

This week I received my kits for repairing the power regulation circuit of my lynxes, so it was time to work on them today.

First, my definitely dead fried lynx as a training

2021-10-17--01-training-in-progress.jpg
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So far so good...

2021-10-17--02-training-is-successfull.jpg
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Now on the still alive lynx, one of the transistor had a catastrophic failure, the reason why the previous owner did a bypass mod that was slowly killing the console, mod that I had removed last time.

2021-10-17--03-dead-transistor.jpg
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But one of the pad did not survive the removing of the dead transistor...

2021-10-17--04-noooooo-no-god-nooooo.jpg
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I was fortunate enough to see that I could do with a bodge wire...

2021-10-17--05-bodge-wire-to-the-rescue.jpg
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This lynx is safe now :cheer: There is trouble with the directional pad, but that will be for a next time.

2021-10-17--06-i-love-it-when-a-plan-comes-together.jpg
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

My lynx is fully functional, after troubleshooting the flex pcb. I delicately rubbed the space between the half pads of the "down" direction, and then there was no more unwanted conductivity any more. (and now I have increased by one the choices I have when it's time to choose how to spend my very modest budget for retro stuff...)

Otherwise, these days I am playing/toying/baby-stepping with VHDL again, this time on eda playgrounds. I am doing simple stuff like that : N-bits Serializer - Big Endian - MSB first. Because writing a generic-pipelined-addition-logic-unit-with-mc68k-compatible-ccr (up to 64 bits) just after a tutorial was a bit much. (I did it with ISE and have a working 4bits test bench of that, but I feel the whole thing is "a bit" over-enginereed... :lol: )
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

Today I got some XP at : hand solder pump, desoldering braid...

got loot : DIN 13 video port, ACSI port

2021-10-18--looting-the-donor-machine.jpg
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frank.lukas
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Re: Sporniket's log on hardware stuff

Post by frank.lukas »

sporniket wrote: Fri Aug 27, 2021 4:30 pm I disassembled again my STE ...
Can you test a IDE Interface for me with your STE?

https://forum.atari-home.de/index.php/t ... #msg257819
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

frank.lukas wrote: Sun Oct 24, 2021 9:33 pm Can you test a IDE Interface for me with your STE?

https://forum.atari-home.de/index.php/t ... #msg257819
If I understand correctly, you need an STE with soldered CPU like mine ?

I believe that I can help, just be aware that :
  • I have no IDE device to test with
  • I have no practical experience on using/testing/troubleshooting such kind of devices and interfaces, so you will have to deal with a noob (I am willing to learn and do homework though)
  • I will have to apply the mandatory fix for dma (it's a good opportunity to do it :) )
  • My only tool for diagnostic is a digital multimeter. (I plan to treat myself with an oscilloscope, but it will be next year...)
  • If it's still ok with you, then I will do my best to do it during November, between the 6th and the 30th included, but no promise (each time I work on retro stuff, I have to unshelf and setup all my stuff and then shelf it and cleanup afterwards, so I need to find time ).
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frank.lukas
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Re: Sporniket's log on hardware stuff

Post by frank.lukas »

... the interface works, that's not the point.

https://forum.atari-home.de/index.php/t ... #msg257607

The same Interface works well in a Atari ST or Mega STE or 1040STE (PLCC Sockeat CPU). The question would be does it fit mechanically and is it all ok when the mainboard are in the bottom case. The main problem is the PLCC socket that comes overhead on the CPU. The PLCC socket will likely need to be modified. Maybe the floor from the PLCC socket has to be milled out a bit, no idea? Amiga guys had also some problems with the A600 ...
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

oh, I see. I do not read german, so most of the topic was lost to me.

I feel better at ease to help then. (I still will not be able to do anything most of next week, because of school holidays)
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