V5/TP7 Problem

[gregor]

Hello together,

I have done the DSO and I was on Test-Procedure 1. No LED Flashing, no Buzzer beeping, no Bootloader loading.
I have then testet all the voltages. All voltages are ok, expect V5 on TP7.
I have measured here about -3,6 V. AV- and AV+ are correctly, and all the others also. Then I have double checked the values from R20, R21, R22 an C19 - all OK. Then I have checked all the other parts and have soldered them again. No change.
Could it be a defective LM6172?

Can you please help me?

Thanks and best regards
Gregor

[jye1]

Did you see LCD backlight on? If it was did you see any display on screen?

[gregor]

Hello,

no, at the first start, the backlight was not lit. So i decided to connect C and E on Q2, then ist lit. I can adjust the backlight. But I never saw the red LED flickering or blinking. And I have never seen any things on the display.

I have changes in the meantime several things. The LED, Q2 the Y1 - no change. Q2 was definitely defective. The Y1, too.

Can the U2A also be defective, because of the wrong values von v5/TP7? I'm not able to change ist, because it is SMD.

Can you please help me for more debugging?

Merci and best regards
Gregor

[jye1]

Do you know how to flash AVR micro-controller? It looks the firmware did not run at all. This is likely caused by bad crystal or corrupted codes.

[gregor]

I can lend a programmer from a friend. I have no experience about it, but I will try it.

I there something special to know? Connecting the ISP, which SW do you prefer? Some special values in the SW?

Thank you and best regards
Gregor

[gregor]

USBasp and avrdude. No Chance. No Response from the AVR.

Can you please describe the way to program the boot loader?

Thanks and best regards
Gregor

[jye1]

To use a programmer please pay attention to the following

1 ) Make sure signal connections are correct.
2 ) Target board is powered either by programmer (if programmer can provide power) or by the board itself.
3 ) Correct settings/commands in software that controls programmer.

For USBasp you can refer to this website http://www.fischl.de/usbasp/. There are plenty of information there.

When you do programming please do not try to change the fuse bits. Only flash the bootloader with programmer and then use bootloader to flash the main firmware.

[gregor]

We have tried it several times. I have a friend here with a lot of AVR experience.
It seems the Atmega is defective, too. No response. My friend said: wrong fuses. No chance to change.
In sum: LED, Q2, Y1 and the Atmel are defective.
This ist too much trouble for me. I will not spend another few hours in trouble shooting to see what else is defective. So i give up.

For me it is a shame, it looked good - but costs a few money and a lot of time with no results.

Best regards
Gregor

[gregor]

Success!

The Atmega64 (U4) had a problem. I have changed it, reprogrammed the boot-loader and now it works! It was a hard work..

Thanks and best regards
Gregor

[John07]

Hello gregor! I have the same problem with DSO068. you couldn't write as stitched Atmega64? what fuse bits put?