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Old 01-15-2019, 09:49 PM   #1529
momaka
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Thumbs down Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU

I got five (5) old AS-IS power supplies off of my local CraigsList last summer. Owner said they were bad and/or failed bench testing many years ago. I haven’t tested them yet and don’t know what I will do with them either. But as always, I open up all used electronics I get to check for roaches / pests and clean up if there is dust. So while at it, I took some pictures. The unit I have for you today is an old Leadman.
https://www.badcaps.net/forum/attach...1&d=1547613992
https://www.badcaps.net/forum/attach...1&d=1547613992

I don’t know much when it comes to these old PSUs, but it looks like a unit for AT systems (please correct me if I am wrong.) To be honest, I also didn’t know Leadman was this old as a company. FYI, this is the same company that made many crappy PowMax PSUs later on in the 90’s and early 2000’s.

Model number, as far as I can see, is ALYWA-4-86-XT, at least according to this label on the case:
https://www.badcaps.net/forum/attach...1&d=1547613992

And here is the other label with all the voltage rails and their current capabilities:
https://www.badcaps.net/forum/attach...1&d=1547613992
The distributions seem pretty standard for an AT PSU, with the 5V rail being rated the most (15 Amps) and the 12V rail trailing far behind (4.5 Amps). Of course, those of you who’ve been working with computers long enough to know Leadman and PowMax PSUs, I’m sure you’re probably wondering if the ratings above are actually real. After all, one should never trust a Leadman unit, right?

So let’s have a look inside:
https://www.badcaps.net/forum/attach...1&d=1547613992
At a glance, this PSU doesn’t appear to be bad for an AT PSU. After all, many AT PSUs weren’t packed full like today’s high-power units. But taking a closer look revealed a few things that caught my eye…
https://www.badcaps.net/forum/attach...1&d=1547613992
As you can see, Leadman didn’t skimp on the input filtering just on their ATX PSUs later in the years. Even “back in the days” it appears they were cutting corners… if not outright driving on the bank. In particular, look at that Christmas candy-colored common-mode choke with its telephone-like wires! That’s a classic sign of a nasty cheap PSU. Capacitors C1 and C4 are installed across the Live and Neutral lines, so they should be X2-class rated. Yet, all we get is regular polyester and ceramic caps for C1 and C4, respectively. Then, next to the input caps, you can see some large and small diodes – this is the “bridge rectifier” of the unit… and a staple cost-cutting technique of Leadman / PowMax PSUs (the different diode sizes, that is). As if installing the same bigger diodes for the whole bridge would have been so much more expensive If you thought that’s all, look at the blue wire for the voltage selector switch up there – it’s some thin measly 22 AWG stuff. But the cheapness doesn’t end there, either:
https://www.badcaps.net/forum/attach...1&d=1547613992
Most of the input wires are actually 22 AWG, with ground being 24 AWG! Sure this is a low-power AT PSU, but corner-cutting like this is just silly!

Let’s move onto the secondary side:
https://www.badcaps.net/forum/attach...1&d=1547613992
https://www.badcaps.net/forum/attach...1&d=1547613992
https://www.badcaps.net/forum/attach...1&d=1547613992
Here, we have some interesting surprises – the output filter electrolytic caps are all Japanese brands, and I actually think they may be genuine (most likely because cheap Chinese and Taiwanese caps weren’t widespread back in the 80’s). The black cap is a Nippon Chemic Con SL 16V, 1000 uF (probably for the 12V rail) and the two big gray ones are “NTK” brand, 10V, 2200 uF (probably for the 5V rail). The lack of vents on these caps also suggests this is an old PSU from around the 80’s. This is further supported by the “LEADMAN 1985 PC-150” label on the PCB. Speaking of which, I don’t know if that’s the actual model number of the PSU or just an internal PCB model. But either way, it’s not a good AT PSU (save for the caps, perhaps.) Sure the output caps appear to be fairly large, but also note that there are empty cap spots on the PCB and that some of the output caps installed are smaller than the PCB markings. So I’m pretty sure Leadman was doing more cost-cutting here.

As for the components on the heatsink: I couldn’t get any part numbers off of those, due to them being covered by brackets (that I didn’t feel like removing.) They are all TO-220 parts, though - likely two BJTs for the primary side (can’t imagine this being anything else but an H-bridge PSU ) and two output rectifiers for the 5V and 12V rails. There is another TO-220 component on a separate smaller heatsink on the secondary, which I’m not sure if it’s a regulator or a diode for the -5V or -12V rails. However, that’s all there is to this power supply.

Next, a shot of the PCB solder side:
https://www.badcaps.net/forum/attach...1&d=1547614130
Yet another pointer for this PSUs vintage - the traces definitely don’t appear to be computer-generated, which wasn’t uncommon. The separation between primary and secondary traces appears marginal. It might still be better than some mid-2000’s gutless units of theirs, like the Sun Pro KY-480ATX I posted here a few years ago. And the soldering appears to be done with leaded solder and not that bad.

Last but not least, sharp eyes may have noticed from the case pictures that the fan is missing. Well, this is why:
https://www.badcaps.net/forum/attach...1&d=1547614130
https://www.badcaps.net/forum/attach...1&d=1547614130
https://www.badcaps.net/forum/attach...1&d=1547614130
It’s probably the only issue that is not Leadman’s fault. Looks like a decent fan, TBH. It is ball bearing type too. Brand is ALYWA (same as PSU?) and model number DFB-8A12M, rated for 150 mA @ 12V. Might be worth a short at fixing it, but will see.

Well, that’s all I got for this power supply. No detailed component breakdown again, but I think the pictures speak for themselves. Overall, it's not that terrible when considering this is an AT power supply. In fact, it's probably better than some of the gutless PSUs they produced later in the years. Nevertheless, I still think this unit belongs to this thread, mainly because of the corner-cutting. After all, I posted an Astec PSU of a similar vintage in the Quality Pictorial thread (link here), so I think that explains why I posted this Leadman here even better.

Anyways. I suppose that's yet another gutless Leadman added to my collection. Weeee
Attached Images
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (1).jpg (103.9 KB, 30 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (2).jpg (105.1 KB, 21 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (4).jpg (37.7 KB, 24 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (3).jpg (146.9 KB, 21 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (5).jpg (306.0 KB, 41 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (6).jpg (148.4 KB, 30 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (11).jpg (50.1 KB, 29 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (7).jpg (151.0 KB, 31 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (8).jpg (129.8 KB, 29 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (9).jpg (57.4 KB, 27 views)
File Type: jpg Leadman ALYWA-4-86-XT [Leadman 1985 PC-150] PSU (10).jpg (257.8 KB, 18 views)
File Type: jpg Leadman ALYWA-4-86-XT - fan (1).jpg (48.5 KB, 26 views)
File Type: jpg Leadman ALYWA-4-86-XT - fan (2).jpg (52.3 KB, 32 views)
File Type: jpg Leadman ALYWA-4-86-XT - fan (3).jpg (48.3 KB, 21 views)

Last edited by momaka; 01-15-2019 at 10:02 PM..
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