Might have zapped my 6128...

[JonB]

I think I just killed a 6128 


I was running it off a cheap power supply normally used for hard drives, and I accidentally short circuited the +5v / 0v lines. There was an explosion within the power supply, lots of carbonated parts (once I'd pried it open with a hammer). It's not the first time this happened - it's my fault, I have the +5v line attached to the 6128's trailing lead with a crocodile clip, temporarily.


Now, a short on the 5v line won't necessarily kill it, but an out of control voltage spike on the (still connected at the time) 12v line might. Is this likely, given the 12v circuit is only for powering the drive? (Or am I wrong about that?)


Anyway, when I have time I will do a bit more investigation. I need the 6128 to support my PCW efforts (as you'll know if you saw the post I wrote about how I transfer stuff off the internet to the PCW).


Hooray, I now have two dead 6128s... and they weren't cheap, either!

[Bryce]

If the short circuit happened between the CPC and the PSU then the 6128 will be fine, even if the 12V peaked (very unlikely), the drive probably survived too. Now fix the 5V connection properly before you connect a new supply!

Bryce.

[TFM]

Yes, and start thinking about insulation.

[Badstarr]

"pried it open with a hammer" I like it! Just don't use the same method to open up your 6128! 

[JonB]

False alarm, thank god! It's OK. Yay!

[robcfg]

Phew! Congrats, mate! 

[MacDeath]

OMG, you killed Arnold !!!


(you barstard!)

[JonB]

Yeah.... like... "close one, dude!"


Now I need to fix the other 6128 which has been dead for ages. i replaced all the RAM but no joy. Swapped out the socketed chips one at a time with my working 6128, no joy.

Something's busted and I don't know what...

[JonB]

If the short circuit happened between the CPC and the PSU then the 6128 will be fine, even if the 12V peaked (very unlikely), the drive probably survived too. Now fix the 5V connection properly before you connect a new supply!

Bryce.

Yessir!


These cheap supplies are very noisy though. Might have to stick a smoothing cap in there for good measure!

[Bryce]

As the CPC doesn't have any sort of internal regulator (the 5V goes straight to every IC on the board) you definitely SHOULDN'T be using any cheap unregulated supply!!! Only use a decent regulated 5V supply or you'll damage the CPC eventually. Adding a capacitor won't save you or the CPC.

Bryce.

[JonB]

I don't know that it is unregulated. It's a switched mode supply, intended for powering hard drives. It just seems it wants to be a fuse too.

[Bryce]

A regulated supply won't be noisy.

Bryce.