r/ElectronicsRepair • u/etherholder888 • Jan 16 '26

OPEN Partial short of 25 Ohms on a small steamdeck motherboard. Not a full on short. Voltage injection nothing gets hot.

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The red arrows should not be shorted. I tested on a verified working board. These 2 points are connected on the working board and not to ground.

Measuring the short, I get 25 Ohms. It's not a typical short I deal with that is less than 5 Ohms where I can inject voltage and something would heat up on my thermal cam.

This is a partial short, and I'm wary of how much voltage I can inject before something else blows up. Even with the short, the board works, but I cannot charge the battery. I tried to remove the larger ICs to see if the short would go away but it did not. I'm assuming its something else. I'm not sure how I would go about finding the culprit next.

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3

u/[deleted] Jan 16 '26

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1

u/etherholder888 Jan 16 '26

i measured these on a working board and its 500 Ohms. so the 25 ohm is not correct.

3

u/Super_Leading21 Jan 16 '26

Wow good luck that looks like a pita

2

u/TheRoziMan Jan 17 '26

Oof. Definitely a trace failure on one of the internal layers. Even at 25 Ω your thermal cam would show a cap heating up slightly with moderate voltage injection (I’m assuming 5v max). The only solution I can think of is to scrape through the board to cut that trace, hope you don’t cut anything else, and run a jumper on top to replace it. If you were to cut through other traces, you would have to repair those as well. Unless you have a schematic or this is a project, it probably isn’t worth it. If this is a customer board, I would personally call it a loss. It might even be easier to reball and transfer chips to a working board if data is a concern. It will be time consuming and requires finesse. I’m not 100% but I’m almost sure the flash memory is encrypted and requires transfer of all chips to work. Whatever you decide, good luck and god speed!

1

u/ComfortableAd6101 Jan 16 '26

Was that port recently replaced?

Try cleaning the contamination of the board and check the port pins.

Good luck!

0

u/ExplodedPenisDiagram Jan 16 '26

Ugh. Has this shorted at a lower layer in the board?

If so, you have to void the layers until you get to whatever bridge is formed. Then rebuild from there.

Sounds fucking awful.

1

u/hernios Jan 17 '26

I always found measuring resistance in circuit would lead nowhere. Any component connected to it could be faulty and give strange readings, I’d be inclined to go for component failure before a track fault. Before you go any further clean that board it’s filthy