Fried heatermeter board?


 

Mark-Ontario

New member
If anyone could help me out it would be greatly appreciated.

Attempted to do a 4.3 build and after plugging my pi 2 b into the heatermeter board it started to smoke; the pi's LEDS are now solid and from what I can tell from reading online the pi is friend (not to worried ordered a replacement).

That being said I don't know if I fried my heatermeter board; I tested the voltages (from this link https://tvwbb.com/showthread.php?69974-New-Build-(First-Time)-Problem-with-start-up) and I a few different readouts, notably the Mosfet FQU11P06TU middle prong has zero reading and a few of the capacitors have zero voltage).

As well, when I plug in the heatermeter with the LCD screen the green and yellow LED light up (red does not) and the top row of the LCD displays solid bricks (bottom row nothing).

Anyway to tell if I fried my board at this point in time?
 
Kinda hard to guess at that condition of the HM board at this point, did you determine WHY it started to smoke? Was the rPi mated wrong, is there a part on backward? Do you have a massive short somewhere?

I would start the troubleshooting as simple as possible, testing the HM base board only (no rPi or button board). First examine the board for solder bridges or bent over leads that are shorting, next check the polarity on the diodes, electrolytic (can) capacitors, make sure your transistors are installed to match the printing on the board (all this stuff is clearly marked on the board). You can also check the ATMega is installed in the proper orientation.

If all that looks OK (or has been corrected) then I would connect the base board to the 12v power supply. Then use a voltmeter to check your power supply. 12VDC at the jack, +5VDC at the output of the OKI regulator board, and 3.3VDC at the output of the 3.3V regulator (next to the OKI) (all measurements can be taken with the black lead of your meter on the power jack ground) If you have all three voltages then it would seem your board is ready to move forward, if missing any voltage then troubleshoot power supply.

Your HM will not truely come to life until the rPi connects to it and programs the ATMega, which I assume didnt happen with the smoke and all!
 
Thanks; I've double checked the polarity of the diodes, re checked the transistors and made sure the ATMega is installed in the proper orientation (that being said I don't have the proper voltage readings on the ATMega).

I do have 12v at the power supply, 5VDC at the output of the OKI, not sure where on the board the 3.3VDC regulator is though.

I guess I'll keep my fingers crossed and wait for the new pi.

Regarding determining the smoke, no idea unfortunately; once I saw the smoke I immediately unplugged and disconnect everything. I'm guessing I had it mated wrong. That being said, when I plug my pi into the HM now, I do only have 5V running to the pi so I guess thats good.
 
Right above the OKI voltage regulator (where you measure the +5V) there is a voltage regulator (that looks like a BS170 transistor), the center leg is +5 in, the bottom leg is +3.3V out, the top leg is ground. Make sure you've got 3.3v there, if not, make sure you didnt mix up a BS170 with the MCP1700-33 regulator (again, they look exactly the same except for the printing on them)

If you have 3.3v there then I would carefully mate a new/working rPi and hope for the best. BTW, I would suggest going with a rPi zero-w, works great and is really cheap with built in wifi.

After that you should go through the same inspection process with the LCD board before you plug that in.
 
Thanks, those are the voltages I have (I thought that was a transistor).

And thanks re the Pi zero w, that's the one I ordered; wish more stores sold them physically, paid more in shipping than I did for the board.

Out of curiosity, will the voltages change to the ATMega once its mated and the firmware is installed?
 
I wouldnt worry too much about the voltages on the ATMega at this point, right now the atmega isn't programmed and functioning, so VCC is about all you can predict (which should be 3.3v) I have no way of telling you if the ATMega smoked or not during the mishap, so you have to play that by ear. It may well have fried, or may be fine. If you dont want to take a chance then replace it before you mate the new rPi.

PS keep in mind you probably have to solder header pins to the zero-w before you can use it, so make sure you have those.
 
Thanks for all your help. Realized I need header pins for the zero, thankfully those I have.

I don't think I fried the ATMega, the smoke (from where I saw it) was at the opposite end (seemed to be coming up from the Pi or where the MOSFET area). If the ATMega is fried would it cause damage to the new Pi or just not work?
 
Hard to say, without knowing what caused the smoke in the first place. The highest voltage on the ATMega should be 3.3v, chances are it wont fry the rPi, but what fried the first pi???
 
Highest voltage on the ATMega is 3.3.

Re the smoking: I don't know...I'm guessing I foolishly mis alligned the pins when I mated the boards. After the smoking I re-did some soldering but I didn't see any bent leads or any leads touching which could cause shorts.
 
Pi zero came in, mated it to the heatermeter board and used the pi's power source to power the heatermeter and same issue, top row of LCD is solid and no response.
 
Your HM will not function until the rPi programs the ATMega, maybe your linkmeter build isnt booting properly?

I just powered my HMv4.3 via power from my rPi zero-W and it worked fine. I also powered the rPi zero-W without being connected to the HM board and I could still access the web interface. So I would disconnect the HM board from the rPi to eliminate it as a cause for malfunction and boot the rPi, try to get connected via web interface. If you get the web interface loaded at least you know the rPi is booting the HM OS properly.

Have you ever been able to log into the HM web interface?
 
Tried booting just the pi with the HM OS and I cannot connect to the HM web interface.

Trying to double check to make sure the pi is logging into the wifi network.
 
You could try an Access Point build and connect with a wireless device like phone or tablet, if you dont see the HEATERMETER hotspot then the rPi probably isnt booting. If you have a mini hdmi cable you could connect the rPi to a monitor to watch what is going on. Otherwise, you might try another SD card in case this one isn't programing for whatever reason. I had a microSD lock up on me and no matter what I did I could't undo the digital write protect, tried another card and it worked fine.
 
So When downloading the OS I've been selecting "Client" and inputting my wifi credentials. Should I use the default heatermeter AP?
 
Client download is fine, works great for me now, but I did once have a router that was funny with the HM and took some coaxing to connect. If you have tried client mode, and know you put the right SSID and passphrase and it isnt connecting an AP mode build might be worth a try. At this point you are just trying to prove that the rPi is actually booting the HM software, so far no signs of life... With an AP mode image you should see the HEATERMETER hotspot, if you can't see that then maybe you have an issue with the rPi, SD card or the way you are writing the image or something.
 
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weird, if I do an AP build can't locate the hotspot...the OS when I download is only 28mb; is that the correct size?

Using win32disk imager as suggester.
 
so weird...the led was never booting on the pi, tried another ap build and heatermeter popped up on network. gonna try installing the client on it and seeing if i can access the web OS. thank you again for all of your help and input, it is greatly appreciated.
 

 

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