Analogue Section Reference Voltages

[quango]

Hi,

As I'm trying to troubleshoot my 2nd x0x i thought i would map out the voltages on my other working x0x as a reference. I've done this as a new layer in the Freeware Eagle Layout 5.6 software over the ladyada Eagle mainboard layout.

Here's the modified file to load into Eagle layout

mainboard_with_analogue_volts.zip

(62.9 KiB) Downloaded 693 times

As I'm a total novice myself someone may want to go over this file to OK it but hopefully its fairly accurate. I set every working x0x dial to 0 except for Cutoff which was at about the 2o'clock position.

If you spot any glaring errors please pm me or post here.

I've noticed depending if you hit keyboard buttons when testing voltages this can alter volts drastically in the vco IC's and therefore other parts of the VCO. I believe I had my x0x in keyboard and pressed C to get 2.0V

[reedlaw]

Wow, this is awesome. It will help me a lot. I'm working on my 2nd x0x as well and I need this to troubleshoot. Thanks for the great work!

[mome rath]

stick-eeeeeeeeeeeed

thanks

[Gorx]

I have done some measuring of volts starting from J4 working my way up and found out that my xoxbox has 0 Volts at D25. Is there a switch I didn't turn right?

I suspected Q24, Q25, Q8 or Q27 could be faulty(?) but that's not the case, I changed Q24 and Q25, and swapped Q8 and Q27... nothing improved.

D25 @ 0Volts anyone...???

[MartinDidymus]

I have uploaded a png file for anyone without Eagle software.

[ClockLoop]

AWESOME

VERY useful, thank you.

(this helped me find a 1 meg resistor that was swapped with another resistor of incorrect value.)

[rarara]

is anyone able to flip the .brd supplied above??? i am following the doc and testing my voltages but doing it from the faceplate side for ease. would be much better if the board was flipped, but can't seem to do it with the (freeware) version of Eagle.

anyone help??