Blank Screen. After reset, the device is ready.

Anything about this unique oscilloscope DIY kit
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dkrasny
Posts: 2
Joined: Wed Dec 06, 2017 7:11 pm

Blank Screen. After reset, the device is ready.

Post by dkrasny »

1. When I turn on the device does not always go through a full load. Sometimes when I click on the Encoder button, the booting passes safely
(in the boot process on a screen booting, firmware versions are displayed, and this accompanies the speaker's sound and the D1 LED flashes
on the main PCB), and the oscilloscope is ready for use. And sometimes after turning on the device stop on an blank screen and no
sounds do not emit (LED D1 on the main board does not light up). But if you press the reset button SW12, the boot passes safely.
This effect does not depend: powered by an oscilloscope from an external source via a mini USB connector or from an internal battery.
In addition, sometimes the device hangs, the backlight goes out, the keyboard and the encoder do not respond. It only helps to completely turn off power supplies.
2. On the screen there are icons that are not activated in any way during the operation of the device. For example, the battery icon does not depend on
from the presence of a battery.
3. Charging does not appear on the screen. If I remove the back cover, then during charging on the board BOB2 the core is lit red LED.
4. The device without the battery in the off state does not consume current. In the switched-on - 0,2A. With the battery installed in the off state - 0,23A,
in the switched-on - 0,35А. I see: the process of charging the battery is in progress.
5. All stages of voltage verification and instrument settings were successfully passed. The main PCB is equipped with all 5 PCBs in the set.
The main PCB shorts jumper JP4 and JP7. The device as a whole functions, but for start-up it is often necessary to carry out a reset.
In the set of parts there was no quartz resonator of 20 MHz. To start the device, I purchased it separately at a local store. Resonator in a suitable housing
there was no, so I soldered the resonator in the dip-performance.
Questions:
1. How do I make the device go on ready when turned on without pressing the reset button?
2. How can I make the battery status (charge level, charging process) displayed on the screen?
Attachments
Quartz resonator in a dip enclosure
Quartz resonator in a dip enclosure
Icons on the screen
Icons on the screen
Blank screen
Blank screen
wwe432
Posts: 3
Joined: Fri Nov 17, 2017 5:23 am

Re: Blank Screen. After reset, the device is ready.

Post by wwe432 »

I was having the same problems at first. When I first completed the kit everything seemed to be working. Then it hung up when I tried to use the test signal to adjust the square wave shape. Then, the more I worked with it, it stopped responding to the rotary encoder and the buttons. It would boot up but go no further. The reset button still works, but now the boot screen no longer shows--just a blank screen with a low contrast grid and some symbols at the top of the screen. I have been trying to find out how to re flash the firmware for the control panel processor and the main system processor. I think the boot loaders for these processors are corrupted. I have some AVR programmers but not enough info on them to use them. My only experience with embedded controllers is with the PIC line.
dkrasny
Posts: 2
Joined: Wed Dec 06, 2017 7:11 pm

Re: Blank Screen. After reset, the device is ready.

Post by dkrasny »

I found a way to solve the problem. A crutch, but it works. Drilled the case against the SW12 "RESET" button. I completed the oscilloscope with a toothpick and now I can work ;)
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: Blank Screen. After reset, the device is ready.

Post by jye1 »

This appear to be that the system did not have a proper reset at power-up. One possible cause for such issue is the power up voltage rises too slow. It is suggest to test with different USB cables and/or power sources. If powered by battery please test with fully charged battery. Another possible cause is poor performance of BOB4 (the step-up converter). You can try powering up without BOB4 by closing JP3 when powered by USB. BOB5 typically draws large current. If BOB5 draws too much current it could cause the problem. You can test this by powering with BOB5 removed (of course analog circuit won't work properly in this case).
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