Muzzer wrote: ↑Sat May 01, 2021 9:20 am
That's the underside of the ethernet connector that's burned up. Perhaps you have a voltage between the ends of the network cable. Are the power supplies 0V in your PC and Acorn at different potentials?
The damage looks typical of this. Measure the voltage between the PC RJ45 connector shell and the ACORN RJ45 shell. Do this with the cable unplugged or an unshielded cable. If there is AC or DC voltage, the grounds are not the same between the PC and ACORN.
Oh yeah.. just checked that and I’m getting 94v there. Problem is that pc I’m using is run from 19V psu through simple jack. How am I suppose to ground the computer? All the psu and acorn is plugged into same socket
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 10:23 am
by Muzzer
You'd hope for the 19V PSU to be floating WRT ground. 94V sounds rather a lot, so you'd want to be concerned about what's causing it, not least if it can frazzle your Acorn. If it has enough oomf to can damage the Acorn, it could be hazardous to you.
You should have good hard protective earth connections to the chasses of both the PC and your machine. Then the logical thing would be for both systems to be grounded on the 0V rail.
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 10:26 am
by LenelyWolf
Muzzer wrote: ↑Mon May 03, 2021 10:23 am
You'd hope for the 19V PSU to be floating WRT ground. 94V sounds rather a lot, so you'd want to be concerned about what's causing it, not least if it can frazzle your Acorn. If it has enough oomf to can damage the Acorn, it could be hazardous to you.
You should have good hard protective earth connections to the chasses of both the PC and your machine. Then the logical thing would be for both systems to be grounded on the 0V rail.
Yeah I just realised that.. i’m investigating it now.. it looks like there is something wrong with spindle drive. Still working on it
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 11:14 am
by LenelyWolf
Ok... so I get stuck here... I get 0v between ground and ethernet casing with everything connected apart from analog output from acorn to the dc drive. Once the analog output is connected I get 90V between ethernet casing and ground... I’ve checked all grounding and it looks ok. What else should i check?
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 12:59 pm
by LenelyWolf
I’m gonna buy a new beaglebone which burned and new signal conditioner to get isolation on analog inputs.
Can anyone please provide me with some links and video how to quickly flash and synchronise the beaglebone with acorn? I want to get ready for it so I’m up and running by next weekend again...
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 1:03 pm
by martyscncgarage
Look at KB Electronics KBSI240D signal isolator.
Flashing firmware instructions:
Re: Acorn burned down < strand of hookup wire on board>.
Posted: Mon May 03, 2021 1:08 pm
by LenelyWolf
martyscncgarage wrote: ↑Mon May 03, 2021 1:03 pm
Look at KB Electronics KBSI240D signal isolator.
Unfortunately not available in UK. Do u know any other option?
Re: Acorn burned down < strand of hookup wire on board>.