First Kamikaze, please criticize

[ghoul69]

First OLED mod. I would really appreciate any feedback. Is this a shitshow or an understandable first time?

Successes:

• I believe I've exposed DAT0.
• The point that I believe to be DAT0 measured a little more than 0.450 with the diode test.
• I don't believe I dremeled far enough to brick it.
• I don't believe I damaged the CMD pads.
• I have the tools to fix my mistakes.

Failures (what I've learned (what others told me and I ignored)):

• My dremel was too large. I do not know the size of the tip. It was not given in the kit. I will be getting an appropriately sized bit (0.2mm I believe).
• I completely tore through the adjacent trace because the tip was too large. I have enameled wire with which I can bridge the trace.
• I dremeled the CMD 4.7k resistor and I could not get a reading. I removed it from the board out of respect for the fallen. New ones are on the way.

Plan of action (in that order):

1. Replace the CMD 4.7k resistor.
2. Soldermask it up. Everything. Except DAT0. I'll try to leave the exposed copper of the damaged trace uncovered. If I can leave DAT0 uncovered I can probably do that.
3. Put some solder on DAT0
4. Scrape/dremel to expose copper on the trace I wrecked if needed. Probably scrape since we're so close to the CMD resistor now.
5. Bridge the trace by soldering down 38 AWG enameled wire.
6. Solder mask it up again.
7. Do the rest of the mod.

 

[slimeinacloak]

Firstly its not the worst attempt at a kamikaze mod I've seen so theres that lol
0.2mm grinding tip size is correct (I buy these ones)
I'd recommend masking the area before solding the new CMD resistor to the board (dont want solder getting on the ground layers and being a pain)
With reconnecting the trace you tore I'd recommend using these then masking over the new trace afterwards
Remember when doing the masking you can always just clean it off with isopropyl and try again if you get it somewhere you dont want it or scraping with a new exacto blade works very well

 

[ghoul69]

That is really helpful, thank you very much

 

[TheStonedModder]

Hmm this gives me an idea

If it’s only 0.2mm I wonder if this could be automated with a CNC or even modified 3d printer

Just make a bracket to lock the board down, and micro steps to accurately get your 0.2mm bit where you need and move back and forth a few times

 

[ghoul69]

I have found a thread on reddit where this was discussed. Someone in the comments also claimed to have done this. I've also seen discussion of a jig within which to dremel.

 

[linuxares]

I mean in theory some one could make a plastic holder that only allow it to go down to 0.2 mm. Then also make it so you can fit it around things so it won't move around.

 

[l7777]

A jig should be relatively easy, to be honest there's quite a bit of margin for error if you have the proper tool. The OP's biggest problem was that the grinding bit was too big making it hard to be precise. If you have one of the low speed grinders and the small bit it's a matter of going slow and letting the tool do the work instead of trying to force it with downward pressure.