Worklog Omega trim

[Customledmods]

This is my first attempt on this kind of trim everything was going great until I trimmed the AVE section, after that the board doesn’t boot and my LDO gets super hot.

So I desoldered everything checked resistance and it looks like I have a short on the 1.8v line resistance measured 0.03 ohms.

does anyone with experience on these kinds of trims have any tips on how to troubleshoot? any help is appreciated.

also excuse my dremel slip on one of the ram vias

 

[YveltalGriffin]

So you completely disconnected 1.8V and GND from the AVEflex, and the short was still there?

If so, take a look at the RVK Compendium to see where the 1.8V voltage plane crosses your trim boundary. That's the area you need to inspect / potentially sand more.

(Also, I'm eager to see whether the RAM bodge wire works!)

 

[Customledmods]

Yes also when everything was connected there was a short on the video out as well not sure why.

I hope it does work if not this is a good training trim, I need to master this trim for this year’s competition.

 

[Stitches]

Did you check that the NTC thermistor hasn't fused closed?

 

[Customledmods]

Did you check that the NTC thermistor hasn't fused closed?

No I haven’t I will in a bit I’m going to solder everything back up after sanding the board a bit more.

UPDATE

ok so after soldering everything my 1.8v short is gone and I get all the correct voltages and the NTC is fine, the only thing now is the short on the av out.

 

[Customledmods]

It works yesss also @YveltalGriffin the wire on the ram works so far who knows if it will later on since I haven’t tested a game.

also the real question is wether I’ll be able to use this trim in the competition

 

[CrazyGadget]

Nice!!!! I would assume it would be a no-go for using this trim in the summer competition, given how far out we still are. But hey, this experience will make the next one go by much faster!

 

[Customledmods]

Nice!!!! I would assume it would be a no-go for using this trim in the summer competition, given how far out we still are. But hey, this experience will make the next one go by much faster!

Thanks and for sure it will help a lot, also I really can’t believe how small it is lol for anyone wondering here’s a picture of trim next to my work AirPod case.

 

[LCandell]

View attachment 32763

The ol' reliable NAND bend

Awesome work! Congratulations for your first OMEGA

 

[Customledmods]

Thanks

 

[Customledmods]

UPDATE

I’m going to turn this post into a worklog because I’m working on some kind of a trim and didn’t want to make a new thread.

so I re re soldered my nand and moved it to a new location because I needed the space where it was previously.

 

[LCandell]

Can you explain me please your "wireless" U10 location?

I know I need to take 3.3V and send delayed signal to CPU, but I don't know if the pins of the other side are only soldered together or must be soldered to another place

 

[Stitches]

Can you explain me please your "wireless" U10 location?

I know I need to take 3.3V and send delayed signal to CPU, but I don't know if the pins of the other side are only soldered together or must be soldered to another place

View attachment 33100

There's a GND via directly beneath the blob

 

[subierekt]

It’s not a via, you scratch the solder mask off and there’s ground plane underneath. There is a via underneath the component you solder, you need to make sure it doesn’t bridge

 

[Wesk]

Thanks and for sure it will help a lot, also I really can’t believe how small it is lol for anyone wondering here’s a picture of trim next to my work AirPod case.

Nice work!, just a little pro-tip: you don't actually need a heatsink at all with the metal fan, if you mount the fan diagonally across both chips and use some thermal paste it will keep the temps well under control. Just an option if you're looking to save space.

 

[Customledmods]

Nice work!, just a little pro-tip: you don't actually need a heatsink at all with the metal fan, if you mount the fan diagonally across both chips and use some thermal paste it will keep the temps well under control. Just an option if you're looking to save space.

View attachment 33101

Ohh nice that’s really smart thanks for the tip.

 

[LCandell]

There's a GND via directly beneath the blob

Thanks a lot! For both @subierekt @Stitches