Broken IO6-G bought on eBay

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pentium
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Re: Broken IO6-G bought on eBay

Unread postby pentium » Wed Nov 22, 2017 9:50 pm

The missing component is indeed a fuse. It looks strikingly like a Polyswitch resettable fuse.
My guess is that it and the cap would of been part of the circuit for the voltage regulator immediately next to them.
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mosiniak
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Re: Broken IO6-G bought on eBay

Unread postby mosiniak » Mon Dec 11, 2017 1:32 pm

In http://www.sgistuff.net/hardware/system ... g-2200.jpg you can see the first digit (after manufacturer logo) on C0A8. It is "1"; other characters looks similar to D3H1. Marking "150" indicates 1,5A PTC fuse (http://uk.farnell.com/littelfuse/smd150 ... dp/1175875). Probably the fuse was chosen with some margin and uoy can try any value from 1A to 2A (1 as a first digit). Lower line marking is not important - probably manufacturing date code and may differ between components same components.
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GRudolf94
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Re: Broken IO6-G bought on eBay

Unread postby GRudolf94 » Mon Dec 11, 2017 2:52 pm

I might be echoing others' words here, but I'll say it with my own:

The module itself should still work without that daughterboard, provided you won't use the connectors affected. The issues I see/recommendations I have to make are that:

1) I'd check if the Vin of the regulator is not shorted to Vout (after removing that dead tantalum), and if there is a short, replacing components without fixing the short first is pointless. The short might be the regulator itself, or something else downstream

2) When C0A8 failed, it ripped off/vaporized the traces, and as such, in order to put another PTC there, you'll have to scrape off the varnish from the remainder of trace on the board to solder one side to it, and solder the other leg straight to the voltage regulator (or wherever else it usually went to, but from the pic, it looks like it's the regulator).
My bet is on it being this PTC (but I might be way wrong): http://www.littelfuse.com/products/rese ... 50f_2.aspx
You can substitute any other one with similar trip current and max voltage specs, not necessarily in the same packaging.

3) You can replace the tantalum with a regular electrolytic cap of close value (33uF or in the ballpark) and correct or superior voltage (at least 25V), minding the polarity (dark stripe on the tant is positive, whereas usually electrolytics have the negative side marked with a stripe on the side of the cylinder)

4) Always check your work for shorts (Vin to ground) afterwards, lest you risk toasting your whole system, or at least, the IO6-G

I think that's all. Having done that, and if nothing else failed, it should work just fine. Sometimes all old hardware needs is a little bodge for encouragement.
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