Missing Capacitor, any ideas?

[grobda]

I think my ikari bootleg has a missing cap between the 12v line and ground;

I know some boards have missing components from factory but I'm pretty sure there used to be one there as the reverse of the board has small solder 'mounds' with leg shaped holes in them, as if its been torn out at some point.

There's a fair bit of buzz on the sound so im wondering if this could be the cause, any ideas?

 

[cliff_poole]

Try putting one in, can't do any harm. I'd go with something like 470uf.

 

[PaulSwan]

Should be OK, just make sure you put it in the right way round

Paul.

 

[guddler]

If it wasn't for you saying there's solder on the underside then I'd have bet all out that there was never meant to be anything in there. Must have been a really rubbish soldering job at the factory!

Yeah, try Cliff's suggestion, but given that PSU's can get quite high on the 12v rail as it's usually unregulated, I may be tempted to run with 470uF@25v (rather than the more normal 16v)

 

[grobda]

the soldering on this board is awful, a lot of the pads on the top are bare copper. I put a 470uF cap in and it made no difference so im going to replace the electrolytics in the sound amp area. which will probably make no difference either. then it goes back on the shelf

not a bad game though.

 

[grobda]

im going to replace the electrolytics in the sound amp area. which will probably make no difference either.

it didnt. i replaced the pots too.

 

[grobda]

im going to replace the electrolytics in the sound amp area. which will probably make no difference either.

it didnt. i replaced the pots too.

and the op amps and dac. i think its just shonky bootleg design.

 

[guddler]

doesn't overly surprise me to be honest. it's really not uncommon for bootlegs to suffer in the sound department.

 

[P-Man]

take a photo of the larger sound section, sometimes you can piggyback a ram and the sounds will jump into life or other stuff, but i don't know what is on this pcb to reccomend..