Dynomotion

Group: DynoMotion Message: 4440 From: Troy Date: 3/29/2012
Subject: Fried Kflop

Hello

 

I am still trying to figure out what I did wrong, but in hooking up a breakout board I made, to the kflop, something went wrong and now the kflop doesn’t work anymore.

 

 

Now when I plug in the kflop nothing lights up and the 3.3v regulator gets piping hot along with R5.  R5 is a little black but it looks to be a 1ohm resistor.   

 

 

I was being super careful hooking everything up but towards the end of the day I got tired and I forgot to disconnect everything from power as I was plugging in my ribbon cable. 

 

What are the chances that I just shorted the 3.3v to ground somehow and if I replace the regulator and that resistor I could bring my kflop back from the grave.  (I have access to a hot air rework station so, I am sure I can pull it off)

 

Any other troubleshooting advice will be appreciated.

 

Troy
Group: DynoMotion Message: 4441 From: Tom Kerekes Date: 3/29/2012
Subject: Re: Fried Kflop
Ouch Troy,
 
More than likely the FPGA is blown and drawing high current.  R5 is like a current limiter/fuse between the +5V and 3.3V regulator.  We now populate it with 0.1 ohm.
 
Do you think you can change the FPGA (144 pin Quad pach 20 mil pitch)?  If so I will send you one.
 
Regards
TK 

Group: DynoMotion Message: 4442 From: Troy Date: 3/29/2012
Subject: Re: Fried Kflop

Hi TK

 

That would be great.

 

Sure I think I could handle soldering that fine.  I have done it before but it was just a fine pitched connector.  I put solder paste along all the traces then heated then dragged a soldering iron along them, then use solder wick to fix any bridges.  I can also borrow a rework station if that would work better, I will have to look into it.

 

Will the FPGA need any initial programming?

 

Let me know what I will owe you for it and how to pay.

 

Troy

 

 

 

 

 

From: DynoMotion@yahoogroups.com [mailto:DynoMotion@yahoogroups.com] On Behalf Of Tom Kerekes
Sent: Thursday, March 29, 2012 3:00 PM
To: DynoMotion@yahoogroups.com
Subject: Re: [DynoMotion] Fried Kflop

 

 

Ouch Troy,

 

More than likely the FPGA is blown and drawing high current.  R5 is like a current limiter/fuse between the +5V and 3.3V regulator.  We now populate it with 0.1 ohm.

 

Do you think you can change the FPGA (144 pin Quad pach 20 mil pitch)?  If so I will send you one.

 

Regards

TK 

 

From: Troy <groups@...>
To: DynoMotion@yahoogroups.com
Sent: Thursday, March 29, 2012 2:44 PM
Subject: [DynoMotion] Fried Kflop

 

 

Hello

 

I am still trying to figure out what I did wrong, but in hooking up a breakout board I made, to the kflop, something went wrong and now the kflop doesn’t work anymore.

 

 

Now when I plug in the kflop nothing lights up and the 3.3v regulator gets piping hot along with R5.  R5 is a little black but it looks to be a 1ohm resistor.   

 

 

I was being super careful hooking everything up but towards the end of the day I got tired and I forgot to disconnect everything from power as I was plugging in my ribbon cable. 

 

What are the chances that I just shorted the 3.3v to ground somehow and if I replace the regulator and that resistor I could bring my kflop back from the grave.  (I have access to a hot air rework station so, I am sure I can pull it off)

 

Any other troubleshooting advice will be appreciated.

 

Troy

 
Group: DynoMotion Message: 4443 From: Tom Kerekes Date: 3/29/2012
Subject: Re: Fried Kflop
Hi Troy,
 
ok, see if you can remove the FPGA.  A hot air nozzle shaped for the 144 pin device obviously works best.  Otherwise in a pinch you can cut each leg flush with the FPGA package using an exacto knife.  Then remove each pin from the board individually with a soldering iron.  Then clean extra solder with solder wick and resin - being careful not to damage pads.  Then clean resin with acetone. 
 
Then apply +5V to the board.  You might use USB power because it is limited to 0.5A.  Then check if the 3.3V is normal and nothing is getting warm.  If other things are blown and shorted it is not worth repair.
 
The FPGA is configured by the DSP on power up.
 
Good luck
TK
 
 
 
Group: DynoMotion Message: 4445 From: Troy Date: 3/30/2012
Subject: Re: Fried Kflop

Hi Tk

 

Well I got the chip off the board, plugged it in and that little resistor is still getting hot.  

 

Unless you have another idea, I guess it’s time to put that board in the learning expense column and  buy a new one.

 

Troy

 

From: DynoMotion@yahoogroups.com [mailto:DynoMotion@yahoogroups.com] On Behalf Of Tom Kerekes
Sent: Thursday, March 29, 2012 4:18 PM
To: DynoMotion@yahoogroups.com
Subject: Re: [DynoMotion] Fried Kflop

 

 

Hi Troy,

 

ok, see if you can remove the FPGA.  A hot air nozzle shaped for the 144 pin device obviously works best.  Otherwise in a pinch you can cut each leg flush with the FPGA package using an exacto knife.  Then remove each pin from the board individually with a soldering iron.  Then clean extra solder with solder wick and resin - being careful not to damage pads.  Then clean resin with acetone. 

 

Then apply +5V to the board.  You might use USB power because it is limited to 0.5A.  Then check if the 3.3V is normal and nothing is getting warm.  If other things are blown and shorted it is not worth repair.

 

The FPGA is configured by the DSP on power up.

 

Good luck

TK

 

 

 

From: Troy <groups@...>
To: DynoMotion@yahoogroups.com
Sent: Thursday, March 29, 2012 3:24 PM
Subject: RE: [DynoMotion] Fried Kflop

 

 

Hi TK

 

That would be great.

 

Sure I think I could handle soldering that fine.  I have done it before but it was just a fine pitched connector.  I put solder paste along all the traces then heated then dragged a soldering iron along them, then use solder wick to fix any bridges.  I can also borrow a rework station if that would work better, I will have to look into it.

 

Will the FPGA need any initial programming?

 

Let me know what I will owe you for it and how to pay.

 

Troy

 

 

 

 

 

From: DynoMotion@yahoogroups.com [mailto:DynoMotion@yahoogroups.com] On Behalf Of Tom Kerekes
Sent: Thursday, March 29, 2012 3:00 PM
To: DynoMotion@yahoogroups.com
Subject: Re: [DynoMotion] Fried Kflop

 

 

Ouch Troy,

 

More than likely the FPGA is blown and drawing high current.  R5 is like a current limiter/fuse between the +5V and 3.3V regulator.  We now populate it with 0.1 ohm.

 

Do you think you can change the FPGA (144 pin Quad pach 20 mil pitch)?  If so I will send you one.

 

Regards

TK 

 

From: Troy <groups@...>
To: DynoMotion@yahoogroups.com
Sent: Thursday, March 29, 2012 2:44 PM
Subject: [DynoMotion] Fried Kflop

 

 

Hello

 

I am still trying to figure out what I did wrong, but in hooking up a breakout board I made, to the kflop, something went wrong and now the kflop doesn’t work anymore.

 

 

Now when I plug in the kflop nothing lights up and the 3.3v regulator gets piping hot along with R5.  R5 is a little black but it looks to be a 1ohm resistor.   

 

 

I was being super careful hooking everything up but towards the end of the day I got tired and I forgot to disconnect everything from power as I was plugging in my ribbon cable. 

 

What are the chances that I just shorted the 3.3v to ground somehow and if I replace the regulator and that resistor I could bring my kflop back from the grave.  (I have access to a hot air rework station so, I am sure I can pull it off)

 

Any other troubleshooting advice will be appreciated.

 

Troy

 

 
Group: DynoMotion Message: 4446 From: Tom Kerekes Date: 3/30/2012
Subject: Re: Fried Kflop
Too bad.  We can offer a 50% discount on a new board.  Send me or Dynomotion the appropriate email address and we will send you an invoice.
 
Regards
TK