DSO 068 Oscilloscope

[jeffgarwood]

I get proper power at the first check spot butlow voltage to Y1. I have verified all the solders are through the multi-layered board. I noticed that the brass inserts on the board between R1 and C4 are touching is that a manufacture error that is causing me problems?

[jyephpbb]

Can you please first explain what was the problem with the 068? Did you get any thing displayed on screen or none at all?

[jeffgarwood]

Nothing on the screen. The LED does not blink for the second step test. I cannot get it to pass the power up tests so I have not soldered in the screen at this point. should I solder the body of the crystal to the contact or just the leads as I have done?

[jye1]

For crystal soldering leads to the pads is ok.

Did you get normal power voltage at +5V test point (TP23)?

[jeffgarwood]

no low voltage after first +5 power check point for initial power-up test.

[jye1]

I'd like to suggest you first sort out power supply portion. To do this you can

1 ) By-pass the switch board (BOB3) by closing JP2 (short it with solder) so that you can focus on BOB116, the step-up converter.

2 ) You can even close JP1 if USB power is used so that BOB118 is also by-passed.

With JP1 and JP2 being closed you have only the BOB116 for the power supply circuit. Test the board with this simplified case first.

[jeffgarwood]

I am going to give you 2 scenarios both powered by the USB. first with J1 & J2 open the Vbus has 5vdc, 0vdc at +5 check spot left of sw12. .14vdc at y1 pin 23, .13vdc at c21 & 22.
.5vdc at J5 +5 check pt.

with j1 & J2 closed 5v at VBUS, 5Vdc at +5 chk left of sw12, .11vdc at Y1 pin 23, .11vdc at c 21 & C22, .54Vdc at J5 +5 test point .5vdc at LED.

There is no power when I connect to wall adapter. USB power only

[jye1]

With scenario 2 had JP4 been closed?

[jeffgarwood]

No JP4 is open

[jye1]

JP4 is for protecting the rest circuits in case power supply is abnormal. It should be permanently closed after power supply is tested good. Please refer to the schematic and assembly instruction.