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G4 Cube Circuit diagrams Or.... power socket cap values ?

quantumDavey

New member
Hi All,

I have been working on my G4 cube. Mainly it was to fix the the sticky optical drive, but in the end, though I got the transport of the discs in and out working brilliantly, I must have broken something to do with the the head as it can't seem to read discs anymore. Anyway, I have a sata superdrive which I intend to fit, using a little ide<=>sata card and 3d printed mounting adaptor.

I made up a new ribbon cable with a box connector on the drive end as that's what it needs to be for the ide<=>sata card to plug in to, which meant having to take the cube almost completely apart in order to fit the new cable into the ide socket for nstead of tye existing cable. In the process of taking apart or putting the cube back together, the fan mounting bracket must have gotten bent, as the standoff that matches with the hole near the power input socket clashed with the two tiny smd caps (C140 and C141) which go between two of the socket pins and ground, breaking both caps in the process 😧.

I suspect these are decoupling caps and aren't essential and I that can get away with not replacing them ?
Or
Does anybody know where I can get Circuit diagrams for the cube ?
Or
Does anybody know the value these caps should be ?
Or
Can I get away with just fitting a couple of ceramic disc, say 1uf, caps ?

Anybody any ideas/authoritative knowledge on this ?

Many thanks in advance to anyone who can help. 🙏
 

quantumDavey

New member
I meant to say that the caps go between the two pairs of pins and ground.

I also did have one of the two caps on my table and was trying to see if there were any markings on it with a magnifier, took a break and when I came back to look again, somehow it was gone. Think it must have accidentally got brushed away somewhere - I was thinking of trying to measure its value. I even went as far as getting my mini-vac out, vacuumed all around the desk to a fair distance, emptied the cylinder onto a large piece of paper and did a fingertip search through the contents - no luck.

Just checking the on board caps in the area with my multimeter shows the other identical looking ones on the board to have (in -circuit) values of either 75nf (the most common) , 15nf (the next most common) ' 22nf (a couple) and 250-ish nf (one off). Checking directly across where the caps that broke off should be, I also get 75nf (and falling, like ya do).

Maybe I'll just go without them replaced for the moment and see or maybe just fit a couple of 100nf disc caps - it is the supply in socket after all.

Anybody have any views ?
Anybody think it wouldn't be fine without ?
Anybody think it wouldn't be okay with the disc caps ?

( I could end up with G4 Cube spares to sell, though - if it turns out not to be fine).
 

GRudolf94

Well-known member
I suspect these are decoupling caps and aren't essential and I that can get away with not replacing them ?
Maybe.
Does anybody know where I can get Circuit diagrams for the cube ?
They haven't been leaked.
Does anybody know the value these caps should be ?
A picture would help more than the designators, here. Presumably 100nF. Or maybe 1uF and 10nF, or some similar combo.
Can I get away with just fitting a couple of ceramic disc, say 1uf, caps ?
Assume you mean 0.1uF, but no. Thru-hole parts don't belong on SMD pads.
 
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