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Osborne 1b PSU needed

Sharkonwheels

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Need a PSU board for an O1b, the grey 2nd edition one.

Mine went POOF! a few weeks ago. If someone can also tell me what the name of the part that says "0,1mF @X" on it, I can order the part too.

It let out the magic smoke, so I ran out of smoke.


On the side is says (I think) f0=4,9mHz 250V ~MP - so it has a capacitance value and a frequency.

BpkL9kqCYAEbmDz.jpg
 

Sharkonwheels

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OK - found them at mouser.
(2) .01uF have their cases starting to crack, found those, .01 X-type, 250v, 15mm terminal pitch.

However, the one that blew, .1uF X-type, has a 20mm lead pitch, which NOONE has.. Mouser has 15mm pitch.
Guess it'd be OK to have it a few mm above the board and solder the leads in? I can't find 20mm lead pitch.


UPDATE:

OK - found this, but they call it a Contact Suppressor RC network.
Same thing? It's listed along with the others...

http://www.westfloridacomponents.co...ressor+RC++Network+RS+Components+238-463.html
 
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Sharkonwheels

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Dang

Seems noone has a .1uF 250V unit with a 20mm lead pitch. It's mostly 15mm, or 22.5/25/27.5mm pitch.

Guess I'll keep looking...
 

SpidersWeb

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It's a through hole part with only two pins which should have long bendable leads - I wouldn't worry about the pitch.

15mm - bend leads outwards, then down, creating a 20mm gap, insert/solder/snip excess leads.
22.5mm - just install it as is - worst case it sits a couple of mm above the PCB which you wont even notice, insert/solder/snip excess leads.

I wouldn't go larger in case the new part doesn't fit.
 

tezza

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Yes, Spidersweb is right. You should be able to bend the legs a little if it doesn't quite fit.

By sheer coincidence I have only just now (like 30 minutes ago before I checked the forums) carried out this exact repair in my own Osborne 1b! While I had the PSU out I replaced all three of these types of capacitors that were there, even though two hadn't blown. Because I knew they soon would.

I suggest replacing all three. It will save you opening up the machine again.

Tez
 

ldkraemer

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If you download the PDF of Section F of the Digikey manual (or at least it used to be Section F) you can look through the
EMI section for the same sized Capactors.

Look in pages 1851 & 1852 (175 & 176) in PDF format from that section. Just make sure it is .1uF and Voltage is 250 or greater,
and physical size is close to same, within a few mm.

You likely could just use a Polyproplene type also as ChuckG has discussed in other postings.

Larry
 

Sharkonwheels

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Dang. I had totally forgotten Digikey...
And yeah, I had planned swapping the other two .01uF caps, as they are already cracking in the cases.

How's this, gents:

.1uF (blown one) - this item looks identical, even same color, 20.3mm lead spacing:
http://www.digikey.com/product-detail/en/PME271E610MR30/399-7472-ND/3459464



.01uF caps, 15mm lead spacing:
http://www.digikey.com/product-detail/en/R46KI21000001K/399-9644-ND/3724660

http://www.digikey.com/product-detail/en/R46KI21005001K/399-5457-ND/1930811

http://www.digikey.com/product-detail/en/PHE820MB5100MR17/399-7601-ND/3465773

http://www.digikey.com/product-detail/en/B81141C1103M/495-1656-ND/679519
 
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ldkraemer

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Yes, Digikey (www.Digikey.com) is my first goto place because:
1. Fast Processing & Shipping of order (I usually get my order 3 days from placing order, sometimes 2 days)
2. NO Minimum Order
3. Ships by USPS for cheapest rate
4. I've never had an order messed up, or been shorted an item
5. Orders are saved online, and I can go back through previous purchases if I need a duplicate part
6. Their PDF catalog (or section) let's me locate my part offline.

Don't forget about Mouser Electronics (www.mouser.com) either. They are next in line for things Digikey doesn't have in stock or carry.

And at times I use Jameco Electronics (www.jameco.com) or JDR Microdevices (www.jdr.com), for more computer specific items.


Larry
 

SteveH

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Dang

Seems noone has a .1uF 250V unit with a 20mm lead pitch. It's mostly 15mm, or 22.5/25/27.5mm pitch.

Guess I'll keep looking...
Those Astec power supplies usually have two sets of holes in the PCB for those capacitors, one at 20mm pitch, the other at 15mm. It may not be obvious until you remove the old capacitor. My experience replacing the caps on an Astec AC8151 psu - here.
 

Sharkonwheels

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I figured as much, as the pads were kinda large.
The small caps have 10 and 15mm pitch looks like... and the larger one has 15mm and 20mm pitch pads.

Makes it easier...
 

dwansmith

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I replaced the .1uf and the 0.01uf caps on both of my O1s in April per Tez's notes. I could not find one seller or vendor that carried both, but I purchased them both on ebay:
0.1uf: WIMA MP3-X2 Metalized Paper RFI Capacitors 0.1uf 250vac from http://www.ebay.com/usr/audiograde?_trksid=p3984.m1439.l2754
0.01uf: X2 Polyproplene safety capacitor 0.01uF/275VAC from http://www.ebay.com/usr/2012topdeal?_trksid=p3984.m1439.l2754

Both worked fine. The 0.1uf (larger) caps are 15mm spacing. The fine folks at Astek provide holes for both 15mm and 20mm so just suck out the solder in the unused holes and they'll fit perfectly.
 

Sharkonwheels

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I got 'em from Digikey. Soldered 'em in just fine. However, the O1 is acting flakey - when powered on, pressing ANY key it behaves like if I hit the reset button.

I'll look at it later... it was behaving wierdly before the PSU went out, hope it's just a kb, as I have 2-3 spares :)
 
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