Mega STE

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UnderTheRain
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Joined: 03 Apr 2021 02:08

Mega STE

Post by UnderTheRain »

Hi have a couple of Mega STEs, 1 in bits 1 complete, The complete one sometime flickers when I open the hard disk I thought the hard disk might be failing as its the original so I have put a bluescsi in and it does the same with that. I tried a ultra-satan and again the same thing. It only does it every know any then is likely to be a DMA issue maybe a PSU? (I have a third scrap mobo so I might have another DMA if its not damaged I might try it).

Thanks

Brian
UnderTheRain
Posts: 170
Joined: 03 Apr 2021 02:08

Re: Mega STE

Post by UnderTheRain »

I've read your extensive article on DMA so I would be looking at a PSU, CPY or DMA I'll check my scrap board on the weekend and see what the state of the CPU and DMA are and maybe try swapping them over failing that I'll go through the PSU. You put in a lot of work on DMA's thank you Mr Exxos.
Steve
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Joined: 15 Sep 2017 11:49

Re: Mega STE

Post by Steve »

Can you be a bit more descriptive, when you say 'it sometimes flickers when I open the hard disk' ... What sometimes flickers?
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rubber_jonnie
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Re: Mega STE

Post by rubber_jonnie »

Steve wrote: 21 Mar 2025 07:18 Can you be a bit more descriptive, when you say 'it sometimes flickers when I open the hard disk' ... What sometimes flickers?
I'm with Steve, what flickers? The screen is all I can think of, but if software is working, but the screen is flickering, I can't imagine it being something like DMA or CPU.

Power seems more likely to be the cause to me. Or caps.

A video of the symptom would help.

Usual steps apply, power, clocks etc & remove any socketed ICs clean the pins, tweak the PLCC sockets, spray with contact cleaner and reassemble.
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
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Badwolf
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Re: Mega STE

Post by Badwolf »

Is the Ultrasatan externally powered (ie. not drawing power from the MSTE)?

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