exxos's Atari, Amiga & retro forum

A quick report as to what happened after recapping the Mega STe PSU...

Using the dummy load resistors I quickly checked for each output rail and they were fine. Approx. the same values as before if I recall correctly, so I attached it to the computer and what do you know, the display output looked a whole lot better! The picture was "stronger" meaning more contrasty, perhaps even a little sharper looking. The white in the monochome display now looks more white (not slightly grayish as before), so I must have done something right by recapping the power supply

Time permitting I'll post a "how I did it" here.

Pacman wrote: ↑Fri Oct 13, 2017 6:34 am so I attached it to the computer and what do you know, the display output looked a whole lot better! The picture was "stronger" meaning more contrasty, perhaps even a little sharper looking. The white in the monochome display now looks more white (not slightly grayish as before), so I must have done something right by recapping the power supply

Fantastic news

Yes it just goes to show that looking after the equipment has its rewards

Pacman wrote: ↑Fri Oct 13, 2017 6:34 am Time permitting I'll post a "how I did it" here.

That would be good, as nobody yet has done any guides or anything about things, other than what I posted on my website of course which is just the basic information no guides or anything.

Saying that, I did acquire a box load of the MSTE/TT power supplies a few weeks ago, they are all un-tested, but at some point I will test them and add them to my store. I will also do a guide as well, but I probably won't get chance to do this until next year now.

Thanks!
Yes indeed, maintaining and looking after these dinosaurs sure has its rewards ...sooner or later!

You've already done several very nice guides, so this will be more of a "practical" guide on how I recapped the PSU, not explaining how it works etc.
I'll try to get it done sometime soon.

Pacman wrote: ↑Fri Oct 13, 2017 8:54 pm You've already done several very nice guides, so this will be more of a "practical" guide on how I recapped the PSU, not explaining how it works etc.
I'll try to get it done sometime soon.

I think it helps anyway for people other than myself to write these guides, at least from a more user's point of view of things. Of course all this electronic stuff I have been doing for around 25 years now. Stripping down something repairing and upgrading I could probably do in my sleep.

Though I also remember back in my younger days, trying to follow guides various electronic kits and things confused the hell out of me. Simply changing a transistor would be a week-long epic. So of course it does always help to have guides written by people who have actually gone through the upgrade steps as the problems and questions are more apparent to users than they are to myself.

I probably miss a lot of details out what I write my guides, but a lot of the time I mostly in a huge hurry trying to do a million things at once, so a lot of things do get greatly summarise which may ultimately confuse some people about some things. I do update my website when I get chance, as I do get emails by some people who get confused over what I have written, so things do get updated and amended over time to make it easier for people in the future

We all have our own perspective on things, and the great thing about these forums is that we can all share what we know. I'm in the midst of writing it now and will link to several of your postings which I think will, in total, give a more complete picture of what it's all about

One quick question: regarding the power supply dummy load resistors valued at 10 Ohms and 2.2 Ohms: how many watts are they?
The markings are a bit cryptic:

218-9 10R
202-7 5%M

and:

CGS SBCHE15
2R2 K TD HD

5V 2.2R =
5 / 2.2 = 2.72A x 5V = 11.36W

12V 10R =
12 / 10 = 1.2A x 12V = 14.4W

So I likely used 17 watt resistors.

Thanks. I found some suitable ones:

2.2 Ohms/17 W high power resistor (1 pcs) TE connectivity 2.2 Ohms/6.1V/17W/10% SBCHE152R2K
and
10 Ohms/17W high power resistor (1 pcs) TE connectivity 10 Ohms/13V/17W/5% SBCHE1510RJ

.... if they're not buying your dummy load resistor kit.

i'm almost done writing the "how to" guide but one tiny detail slipped my mind. I believe I attached the resistors to the following output pins as shown below, and leaving them there regardless which output rail I was testing. Does it look right?

Looks right yes. I've not checked the pinnout, so assume you have it correct.

Thanks for confirming. The pinout should be correct.
I've just posted the "how to" here. I hope someone finds it useful.

Pacman wrote: ↑Mon Oct 16, 2017 11:44 pm Thanks for confirming. The pinout should be correct.
I've just posted the "how to" here. I hope someone finds it useful.

Fantastic!