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Forum Index : Microcontroller and PC projects : Well, apparently I have killed my unit.

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yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 08:09pm 04 Nov 2020
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Okay, this has turned into a nightmare...officially!

Got the Retromax today...a day early. I wanted to try it out. You know, they say hindsight is 20-20...you can probably see where this is going...

Hooked it up, like the CMM2...and...it...did...the...same...thing....

Apparently, there is something wrong with that power supply. Why? How? This supply has 2 mains plugs and two USB ports. After much cursing...haven't thrown anything yet...what I found is that one port is apparently dead, I get no voltage on Pin 1 of the B connector. The other port, I get ~5V on pin 1, like 2.6V on pin2 and 2V on pin 3 or vice-versa. I've checked from a laptop and from a USB hub connection and I only get 5V on pin 1.

The Retromax will show up as a serial port, but it's not right...although I've never used this terminal connection before and don't know what is 'right'. I only sometimes get  the CMM2 'mast head' and no other activity except garbage or nothing.

I can't get the a-a connection to work at all, but this is a different beast and I may not be doing something correctly.

The power switch is different and I haven't figured out how to check those voltages yet. Checking the regulator I get 3.3V in 2 places and 4.8V on the other. I did get 5+ volts once...not sure why not now.

I'm definitely not working on this one...stuff is too closely spaced and smaller!

I think I'm going to try to solder the CMM2 now...regulators came today. I'm never using that other thing again....but I thought it was the fast charger...now...I really don't know.


Steve...the CMM2 destroyer (just call me killer!)
 
TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 6269
Posted: 08:31pm 04 Nov 2020
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  Quote   Checking the regulator I get 3.3V in 2 places and 4.8V on the other. I did get 5+ volts once...not sure why not now.

That sounds close enough to be all good.

The other odd voltages on the USB B connector data pins is OK. "Smart' power supplies can do that and the dumb one are much better to use.

With the system plugged into your PC and terminal program running, pressing the reset button on the CMM2 should give you a sign-on banner.

I won't be around today so all I can do is say "Good luck and don't give up"

Jim
VK7JH
MMedit
 
yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 09:44pm 04 Nov 2020
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Okay, soldered the regulator on to the v1.5 board...but not C5. With the a-b connected to a laptop and the jumper set to run:

a  b  C
|  |  |
=======
=======
 |||
  d

a=4.94v
b=3.31v
c=0v
d=3.31v

all checked to pin6. Center pin of power switch to pin 6 checks 4.94V. Activity light (red) is out. With power switch off, all pins of regulator check 0v, center pin of switch checks 5.11v.

If I plug a keyboard in and turn power on, red light stays on, signal lamp on monitor turns green (from amber), but no display and com3 show up on laptop. I get a some garbage characters if I press reset, in Teraterm. Port is set to 115200, 8N1. I played with parity settings...no change. A-A connection no longer connects as....whatever that connection is called. Voltages are more or less identical in flash mode.

Presumably, I need to re-install C5. I guess I will do so...not much good in this state.

ANything else I can check?

-the destroyer
 
yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 09:53pm 04 Nov 2020
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  yock1960 said  Okay, soldered the regulator on to the v1.5 board...but not C5. With the a-b connected to a laptop and the jumper set to run:

a  b  C
|  |  |
=======
=======
 |||
  d

a=4.94v
b=3.31v
c=0v
d=3.31v

all checked to pin6. Center pin of power switch to pin 6 checks 4.94V. Activity light (red) is out. With power switch off, all pins of regulator check 0v, center pin of switch checks 5.11v.

If I plug a keyboard in and turn power on, red light stays on, signal lamp on monitor turns green (from amber), but no display and com3 show up on laptop. I get a some garbage characters if I press reset, in Teraterm. Port is set to 115200, 8N1. I played with parity settings...no change. A-A connection no longer connects as....whatever that connection is called. Voltages are more or less identical in flash mode.

Presumably, I need to re-install C5. I guess I will do so...not much good in this state.

ANything else I can check?

-the destroyer


Just had an idea...I'm in flash mode jumper-wise, power on, checked from d on the regulator to the plus pad of C5...it connected the DFU thingy...Cube says it read the flash...firmware 0x011a...is that right? Anyway, seems like C5 is necessary.

-the destroyer
 
yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 11:26pm 04 Nov 2020
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Okay, I'm outta bullets!

Fixed trace, put in C5..dead bug style. DFU connects, flashes..FWIW. Serial port shows up, but doesn't appear to work. From what I've learned here so far, voltages look correct. I tested continuity from my trace fix. I have continuity from the - side leg of C5 to C17, I have continuity from the + side leg of C5 to the middle leg of the power switch. As best I can tell, nothing is shorted from my fixes. Still doesn't work.

I'm gonna wait for Mars to rise then go take some videos and try not to think about either of these bricks for the rest of the day!

-destroyer out!
 
TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 6269
Posted: 05:40am 05 Nov 2020
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I hope you have put the flash jumper back to 'run'
With that in 'flash' you will get the symptoms you are describing

Jim
VK7JH
MMedit
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9588
Posted: 05:47am 05 Nov 2020
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New regulator voltages look pretty much spot-on.  Everything should be working at this point, I would have thought.

I agree with Jim on the jumper - I did that once or twice myself when doing my QC before sending things out.....
Smoke makes things work. When the smoke gets out, it stops!
 
matherp
Guru

Joined: 11/12/2012
Location: United Kingdom
Posts: 10209
Posted: 07:58am 05 Nov 2020
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Assuming the chip flashes correctly then the processor is not completely dead. One difference between flashing and running is that the processor is using an internal clock rather than external. My next move would be to replace the oscillator/crystals. Also check the RTC battery.
 
yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 10:02am 05 Nov 2020
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Okay, this is really weird. Both units work....when I connect them to a different monitor! So, somehow, this oldish vga monitor took a dump...why....coincidence...and this intereferes with normal cmm2 ops? So, perhaps I lost some...hair...time from my lifespan...and...well, the voltages on my v1.5 unit were wonky...so maybe not.

Can someone attempt to explain why this could have happened, when connecting to a power source, that shouldn't have done this?

I'm still trying to diagnose the monitor, but it puzzled me that with the status light green...the menu button did not display the menu. Anyone know about monitors?

Steve- the confused
 
yock1960
Senior Member

Joined: 18/08/2020
Location: United States
Posts: 167
Posted: 11:18am 05 Nov 2020
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  yock1960 said  Okay, this is really weird. Both units work....when I connect them to a different monitor! So, somehow, this oldish vga monitor took a dump...why....coincidence...and this intereferes with normal cmm2 ops? So, perhaps I lost some...hair...time from my lifespan...and...well, the voltages on my v1.5 unit were wonky...so maybe not.

Can someone attempt to explain why this could have happened, when connecting to a power source, that shouldn't have done this?

I'm still trying to diagnose the monitor, but it puzzled me that with the status light green...the menu button did not display the menu. Anyone know about monitors?

Steve- the confused


And now I have come full circle! I unplugged the VGA monitor and to make a long story short, it works again. So, the monitor was...confused, something that wasn't being reset by cycling the front power button.

Live and learn.

Thanks for all the help!    Whew!  

Steve
 
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