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Roadrage 2014 gets hot...

Started by PhiloB, May 27, 2014, 01:16:31 AM

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PhiloB

May 27, 2014, 01:16:31 AM
And only puts out 8.9-9.2 V at the 18V pad.
I'm using the LT1054 IC.

I've triple checked the component values and solder points.  Any ideas?

PhiloB

#1
May 27, 2014, 01:35:54 AM
I'm not great with schematics, but should D4 be reversed (polarity wise)?  The document shows D3 and D4 facing the same direction.

PhiloB

#2
May 27, 2014, 02:01:05 AM
Looked at the schematic again and it looks like the diodes are oriented properly.  This really has me confused.

jubal81

#3
May 27, 2014, 02:08:54 AM
Lift pin 1 of the IC out of the socket.
"If you put all the knobs on your amplifier on 10 you can get a much higher reaction-to-effort ratio with an electric guitar than you can with an acoustic."
- David Fair

Matt

#4
May 27, 2014, 02:16:45 AM
I can't tell for sure from the picture but it looks like pin 3 and 5 might be connecting through the trace.
Matt

PhiloB

#5
May 27, 2014, 02:36:34 AM
Jubal, why is this not in the documentation?  I'll give it a shot.

PhiloB

#6
May 27, 2014, 02:42:01 AM
bent PIN 1 up and still gets hot real quick.  Voltage at the 18V out is still just below 9V

the3secondrule

#7
May 27, 2014, 02:45:12 AM
Quote from: jubal81 on May 27, 2014, 02:08:54 AM
Lift pin 1 of the IC out of the socket.

Shouldn't need to lift pin 1, as per the build docs the bst pads haven't been jumpered so pin 1 & 8 won't be connected...
"I have many leatherbound books, and my apartment smells of rich mahogany"

PhiloB

#8
May 27, 2014, 02:55:07 AM
Matt nailed it!!! When I transferred the image for etching there was an issue.  2 traces were connected that weren't supposed to be connecting PIN 3 and 5.  Little razor blade action and now have 18V!!!!!!
Thanks guys.

Matt

#9
May 27, 2014, 02:56:54 AM
Quote from: PhiloB on May 27, 2014, 02:55:07 AM
Matt nailed it!!! When I transferred the image for etching there was an issue.  2 traces were connected that weren't supposed to be connecting PIN 3 and 5.  Little razor blade action and now have 18V!!!!!!
Thanks guys.

good deal!  Glad to help!
Matt

PhiloB

#10
May 27, 2014, 04:02:31 AM
Don't think I ever would have caught that.  I'll be checking continuity on my Quadrovibe etch tomorrow before populating.  Lesson learned....hopefully;)

madbean

#11
May 27, 2014, 04:08:50 AM
Quote from: PhiloB on May 27, 2014, 02:36:34 AM
Jubal, why is this not in the documentation?  I'll give it a shot.

It is in the documentation on page 3.

QuoteConnect BST Pads? The two pads labeled "BST" on the PCB must be connected according to the list above. Failure to connect the BST pads correctly will result in an audible whine in your audio path. The LT1054 is the only one that does NOT need the pads connected.

Matt

#12
May 27, 2014, 04:29:53 AM
Quote from: PhiloB on May 27, 2014, 04:02:31 AM
Don't think I ever would have caught that.  I'll be checking continuity on my Quadrovibe etch tomorrow before populating.  Lesson learned....hopefully;)

It looked like those 2 traces were really close on the template. That's the only thing that drew me to it.
Matt
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