QCX: top row blocks on display, but CPU responds to ISP #avr #display #troubleshooting


Andrea Massucco IZ1IVA
 

Hi,

I've given another look at my faulty QCX (see https://groups.io/g/QRPLabs/message/42064 ), which all of a sudden stopped booting up. I've had success hooking it up to a PC via an AVR programmer: the CPU responds and I was even able to upgrade the firmware from 1.03 to 1.07a!

Alas, the QCX still displays a row blocks on its display, so I'm again stuck...

Any ideas?

Cheers
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net


Gary Bernard
 

Just a long shot, have you adjusted for contrast?


-----Original Message-----
From: Andrea Massucco IZ1IVA <ml@...>
To: QRPLabs@groups.io
Sent: Sun, Jun 20, 2021 11:35 am
Subject: [QRPLabs] QCX: top row blocks on display, but CPU responds to ISP #avr #display #troubleshooting

Hi,

I've given another look at my faulty QCX (see https://groups.io/g/QRPLabs/message/42064 ), which all of a sudden stopped booting up. I've had success hooking it up to a PC via an AVR programmer: the CPU responds and I was even able to upgrade the firmware from 1.03 to 1.07a!

Alas, the QCX still displays a row blocks on its display, so I'm again stuck...

Any ideas?

Cheers
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net






Andrea Massucco IZ1IVA
 

On Sun, Jun 20, 2021 at 07:59 PM, Gary Bernard wrote:

Just a long shot, have you adjusted for contrast?
I have.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net


Jack G5JDA
 

I suggest to try the following:
- double check ATmega is properly seated in socket
- resolder socket pins in case there is a dry-joint
- resolder display pins in case there is a dry-joint

Fairly quick things worth ruling out


jerry@tr2.com
 

Second the motion on resoldering the display pins. I had this very problem yesterday,
and that was the cause. The plating on the pins does not eagerly accept solder, and you
have to insist a little.

- Jerry KF6VB

On 2021-06-20 13:17, Jack M7JDA via groups.io wrote:
I suggest to try the following:
- double check ATmega is properly seated in socket
- resolder socket pins in case there is a dry-joint
- resolder display pins in case there is a dry-joint
Fairly quick things worth ruling out
Links:
------
[1] https://groups.io/g/QRPLabs/message/67521
[2] https://groups.io/mt/83671700/243852
[3] https://groups.io/g/QRPLabs/post
[4] https://groups.io/g/QRPLabs/mutehashtag/avr
[5] https://groups.io/g/QRPLabs/mutehashtag/display
[6] https://groups.io/g/QRPLabs/mutehashtag/troubleshooting
[7] https://groups.io/g/QRPLabs/editsub/243852
[8] https://groups.io/g/QRPLabs/leave/10312280/243852/1190336630/xyzzy


Andrea Massucco IZ1IVA
 

Thank you gentlemen, unfortunately resoldering hasn't solved the issue. Since che CPU is working (as it's accessible via ISP), I'm tempted to blame the display assembly, perhaps the rubber contacts between the display and the PCB... if that's the case I fear I'd need a new display board.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net


 

Did you try swapping out the IC2 for one where the display is good? I did that and the display worked again as it also got the row of blocks on the top, but, the RX has also gone. Both RX and display were fine, this is a neewly constructed QCX-2017-v-2, all was good except TX which blew earlier. In its Baumatech case, running for weeks on RX with no issues (and not TX), from one day to the next on power up there was the blocks along the top. Normally this one required starting twice to get it to power up (old bug, which hasn't been fixed on this model), but this time no, just blocks on the display. Swapping out IC2 from another QCX brought the display to life, but no RX!

I'll try to trouble shoot it at some point with help from this list but for now just wondering if your problem might be similar. Presumably you can't hear the RX withouut being able to start it up with the display? And presumably you have tried putting in a different working IC2?

77 de Lou

On 23 Jun 2021, at 19:58, Andrea Massucco IZ1IVA <ml@...> wrote:

Thank you gentlemen, unfortunately resoldering hasn't solved the issue. Since che CPU is working (as it's accessible via ISP), I'm tempted to blame the display assembly, perhaps the rubber contacts between the display and the PCB... if that's the case I fear I'd need a new display board.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net




--
Love 30m and CW?
http://www.30cw.net


Andrea Massucco IZ1IVA
 

Il giorno 24 giu 2021, alle ore 05:03, VK5EEE <vk5eee@...> ha scritto:

Did you try swapping out the IC2 for one where the display is good? I did that and the display worked again as it also got the row of blocks on the top, but, the RX has also gone. Both RX and display were fine, this is a neewly constructed QCX-2017-v-2, all was good except TX which blew earlier. In its Baumatech case, running for weeks on RX with no issues (and not TX), from one day to the next on power up there was the blocks along the top. Normally this one required starting twice to get it to power up (old bug, which hasn't been fixed on this model), but this time no, just blocks on the display. Swapping out IC2 from another QCX brought the display to life, but no RX!
Dear Lou,

I’m in that EXACT, WORD-BY-WORD, XEROX-COPY situation: same year, same case, same sudden death, same silent RX, same blown and replaced finals!
I believe we’ve found a pattern, but unfortunately I’m unable to test a second IC2, as I haven’t got one.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net



--
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net


va3rr
 

Andrea;

I had a QCX 'classic' sitting in the drawer for a year, and one of the inductors providing VCC to the 328p processor became open. I was able to upgrade the firmware, even though the 328p would not boot up...

I can't remember now if it was L5 or L6, but check both...


 

We'll keep each other posted, I'm following this topic. You can try ordering IC2 replacement from the shop at QRP Labs 6 USD or 4 something Euro. if you will need that, I'm hoping to get trouble shooting help at some point, and will let you know what happens, when I can get around to it!

On 24 Jun 2021, at 14:56, Andrea Massucco IZ1IVA <ml@...> wrote:

Il giorno 24 giu 2021, alle ore 05:03, VK5EEE <vk5eee@...> ha scritto:

Did you try swapping out the IC2 for one where the display is good? I did that and the display worked again as it also got the row of blocks on the top, but, the RX has also gone. Both RX and display were fine, this is a neewly constructed QCX-2017-v-2, all was good except TX which blew earlier. In its Baumatech case, running for weeks on RX with no issues (and not TX), from one day to the next on power up there was the blocks along the top. Normally this one required starting twice to get it to power up (old bug, which hasn't been fixed on this model), but this time no, just blocks on the display. Swapping out IC2 from another QCX brought the display to life, but no RX!
Dear Lou,

I’m in that EXACT, WORD-BY-WORD, XEROX-COPY situation: same year, same case, same sudden death, same silent RX, same blown and replaced finals!
I believe we’ve found a pattern, but unfortunately I’m unable to test a second IC2, as I haven’t got one.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net



--
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net




--
Love 30m and CW?
http://www.30cw.net


Andrea Massucco IZ1IVA
 

Il giorno 24 giu 2021, alle ore 17:12, va3rr via groups.io <va3rr@...> ha scritto:

I had a QCX 'classic' sitting in the drawer for a year, and one of the inductors providing VCC to the 328p processor became open. I was able to upgrade the firmware, even though the 328p would not boot up...
You actually made me realize I did remove L5 a long time ago to reposition it under the PCB as per the modification appeared on https://qrp-labs.com/qcx/qcxmods.html , only I somehow failed to complete the mod and I’ve lost L5! So I’ve replaced it with a Schottky diode as per G3JRH’s modification. Voltages to the CPU are correct, but still no joy…

Cheers

--
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net


Andrea Massucco IZ1IVA
 

Il giorno 24 giu 2021, alle ore 18:44, VK5EEE <vk5eee@...> ha scritto:

We’ll keep each other posted, I'm following this topic.
Definitely!

You can try ordering IC2 replacement from the shop at QRP Labs 6 USD or 4 something Euro. if you will need that, I'm hoping to get trouble shooting help at some point, and will let you know what happens, when I can get around to it!
I’d do it, but first I’d like to know whether it’s possibile the CPU might be partly damaged, i.e. ISP is simply accessing its internal memory but the part that should actually run the code is shot. I don’t even know if that’s possible, as I’m completely oblivious of the inner workings of a microcontroller!

Cheers

--
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net