Replacement PS for Mega STe, meanwell RQ-85

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jacolover
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Replacement PS for Mega STe, meanwell RQ-85

Post by jacolover »

Well, I have gone round and round with teh original supply, its pulsing its output and I have read/watched so many SWPS videos and tried testing and replacing every part on the input and output to no avail, can't get this damn supply working. The only thing left is the transformer, everything else is good and/or replaced, it's past time to move on. So I am looking at a compact Meanwell RQ-85B supply, it should fit with no changes, the only hiccup is there is no "PG" line on the meanwell, so I am left to ask if I need that to make this work in the mega ste. While I am new to SWPS, I have been working in analog electronics for years and am pretty comfortable with my skills and knowledge, plan to up my digital knowledge when the semester ends,. Really frustrating with the Phihong, but it's past time to throw in the towel. Thanks
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exxos
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Re: Replacement PS for Mega STe, meanwell RQ-85

Post by exxos »

You are testing the original power supply under load I assume ?
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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frank.lukas
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Re: Replacement PS for Mega STe, meanwell RQ-85

Post by frank.lukas »

Try to connect the PowerGood line to +5V ...

The Atari TT and Mega STE Power Supplies are really good !
jacolover
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Re: Replacement PS for Mega STe, meanwell RQ-85

Post by jacolover »

exxos wrote: Fri Apr 30, 2021 9:01 pm You are testing the original power supply under load I assume ?
No, haven't done that, didn't want to chance the computer. Any suggestions on what to load it with? And would I need to load all rails? Thanks!
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exxos
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Re: Replacement PS for Mega STe, meanwell RQ-85

Post by exxos »

jacolover wrote: Sat May 01, 2021 12:47 am
exxos wrote: Fri Apr 30, 2021 9:01 pm You are testing the original power supply under load I assume ?
No, haven't done that, didn't want to chance the computer. Any suggestions on what to load it with? And would I need to load all rails? Thanks!
Something like this https://www.exxosforum.co.uk/atari/store2/#0070

Just goes to show how bad information is on the internet if this basic step was never mentioned. There's probably nothing wrong with your psu.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
jacolover
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Joined: Sun May 03, 2020 6:40 am

Re: Replacement PS for Mega STe, meanwell RQ-85

Post by jacolover »

Well, I tried to load the supply with a floppy drive, still I am getting is the pulsing, the fan pulsing, the drive pulsing, the 5v rail pulsing, what s dog this has turned into!
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exxos
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Re: Replacement PS for Mega STe, meanwell RQ-85

Post by exxos »

A floppy drive is no where near good enough. Get a couple of 12v 21watt car lamps or something..

Its normal for PSUs to turn off when not under a proper load.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
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