HS-81, anyone know part numbers?

[sneasle]

I was using an HS-81 as the tail servo on my heli. Part of my blade grip locked up which caused the assembly to fuse and the servo to burn out.

I opened it up and it looks like it got really hot inside, hot enough for 2 of the sot 23 footprint components to desolder themselves and for one of them to burn.


So.. that being said, I would like to try and find replacements for these components. There are 4 of them side by side on the top of the board. I am assuming (based their footprint) that they are either diodes, regulators, or a transistor of some kind.

They each have a 3 letter marking, 2 say UXR, one says UYR, and I can't make out whether the fourth is UXR or UYR, but I am leaning toward UYR.

Can anyone lend some input?

[Ron W3FJW]

Can't help with identification but,
A new servo is the easiest way out if you want to avoid headaches. Probably cheaper if you put any value on your time. Since it got that hot, I wouldn't trust any of the components on the board to be good.

[sneasle]

Ya, I don't plan on trusting it, but I love to tinker and would like to get it working again for the heck of it.

[AndyKunz]

It's probably the H-bridge that died. They're just transistors - either NPN or N-FET. I'm not about to open one of mine to fix it, but you should be OK to insert just about anything you find. The footprints are standardized.

Andy

[sneasle]

Thanks for the input.

ya, looking at the traces you might be right on the H-bridge idea.

I guess I'll spend some time on digikey and see if I can find some trxs in the correct series as these.