Title: Burnt Capacitor on cube motherboard question
Post by: Rob Blessin Black Hole on July 25, 2013, 11:18:32 PM
Post by: Rob Blessin Black Hole on July 25, 2013, 11:18:32 PM
Hello NeXT Community: I'm helping out Isaac, his dad had a cube in storage for 20 years. I walked him through replacing the bios battery and upon power up , she started to smoke: 
I looks like it burned a capacitor and maybe damaged the board and other components. I haven't seen this before outside of a lightening strike , anyone have an ideas on what caused it . Age of the components? Storage for to long possibly? Power supply?
Also can this be repaired ?
I'm leary about using another motherboard if it is a power supply issue, they want to sell the cube but not sure how to price it with the damage...
Any help appreciated as we all want to prevent this from happening to anyone else!!! I try to go through systems completely blowing dust bunnies out before powering them up but this was all over a series of phone calls just trying to help them out and I didn't realise she had been stored that long or would have had further advice. Best Regards Rob Blessin :? [/img]
Also can this be repaired ?
I'm leary about using another motherboard if it is a power supply issue, they want to sell the cube but not sure how to price it with the damage...
Any help appreciated as we all want to prevent this from happening to anyone else!!! I try to go through systems completely blowing dust bunnies out before powering them up but this was all over a series of phone calls just trying to help them out and I didn't realise she had been stored that long or would have had further advice. Best Regards Rob Blessin :? [/img]
Title: Burnt Capacitor on cube motherboard question
Post by: barcher174 on July 26, 2013, 02:24:01 AM
Post by: barcher174 on July 26, 2013, 02:24:01 AM
Hi Rob,
You should be able to use my PSU pinout to test if proper power is coming out.
http://asterontech.com/Asterontech/Next_ATX_Conversion_REV1/
It looks to me like the cap was over volted. It looks like a tough repair, but it's hard to say until the board is cleaned up. I would check the voltages on the board before just putting another one in.
--
Brian
You should be able to use my PSU pinout to test if proper power is coming out.
http://asterontech.com/Asterontech/Next_ATX_Conversion_REV1/
It looks to me like the cap was over volted. It looks like a tough repair, but it's hard to say until the board is cleaned up. I would check the voltages on the board before just putting another one in.
--
Brian
Title: Burnt Capacitor on cube motherboard question
Post by: mikeboss on July 26, 2013, 02:29:59 AM
Post by: mikeboss on July 26, 2013, 02:29:59 AM
Title: Burnt capacitor
Post by: Rob Blessin Black Hole on July 26, 2013, 03:12:12 PM
Post by: Rob Blessin Black Hole on July 26, 2013, 03:12:12 PM
Hello Brian and Mike: Thank you for your advice and for pointing out they put it up for sale on eBay . Everything else looks to be in good condition but I would be cautious about bidding . Testing the Psu like Brian suggests may unmask the problem , I think a replacement motherboard, powersupply and back plain would probably yield a nice cube as it was boxed for that long. Best regards Rob Blessin
Title: Burnt Capacitor on cube motherboard question
Post by: pentium on July 26, 2013, 08:01:49 PM
Post by: pentium on July 26, 2013, 08:01:49 PM
QuoteIt looks to me like the cap was over volted.The cap would be in much worse condition if that was the case.
Looks like a high resistance short happened between layers. Not really the fault of the PSU because the short would not of been enough to trip the internal protection.
Does the system still run or did the self-destruct take it out for good?
Title: Burnt Capacitor on cube motherboard question
Post by: Rob Blessin Black Hole on July 27, 2013, 01:03:17 AM
Post by: Rob Blessin Black Hole on July 27, 2013, 01:03:17 AM
Quote from: "pentium"QuoteIt looks to me like the cap was over volted.The cap would be in much worse condition if that was the case.
Looks like a high resistance short happened between layers. Not really the fault of the PSU because the short would not of been enough to trip the internal protection.
Does the system still run or did the self-destruct take it out for good?
It stayed on the login screen until he pulled the plug, understandably he doesn't want to turn it back on.
I know I'm going to make sure and open them all up when they come in and look everything over first before powering up.
Best regards Rob Blessin
Title: Re: Burnt Capacitor on cube motherboard question
Post by: cubist on July 27, 2013, 10:48:27 PM
Post by: cubist on July 27, 2013, 10:48:27 PM
Quote from: "Rob Blessin Black Hole"I walked him through replacing the bios battery and upon power up , she started to smoke:
The first photo looks like a typical electrolyte failure/internal short. Clean up the board, replace with equivalent part (perhaps with 105C temp) and test with disk/ND removed. Expect other electrolytics to fail in the future, they're getting to that age. The second facebook photo showing the failure in progress is pretty impressive.