Control board for Thelin Parlour 3000 pellet stove.

Thread Starter

v-8 volvo

Joined Mar 29, 2011
5
Hello,
I am in the process of troubleshooting the above mentioned circuit board. The pellet stove operates on 120VAC and 12VDC. There is a simple step down transformer and full wave bridge rectifier mounted in the base which supplies 16 VDC to the control board. There is a green LED on the board which indicates that power is present. It is also supposed to flash.
With the line cord plugged in as well as a battery connected to the 12 v terminals, the "heartbeat" light on the board is barely illuminated (can only be seen if room lights are off). The switch board with LED indicators for off, low, med, high and clean settings light up when you select a function. Also, when you first plug the unit in, the convection/combustion blower runs for a few seconds and shuts off as it should. I tested the large filter capacitor on the board with our Sencore Cap checker and it's ok. That's about as far as I got so far. I will post pics of the board and wiring diagram later.
Does anyone have any experience with these?
Thanks
 

Thread Starter

v-8 volvo

Joined Mar 29, 2011
5
I'm truly overwhelmed by all of the great "replies". o_O;).
I made a test harness out of a DB37 connector with ribbon cable from a video matrix switching bay I had laying around, and a connector with a pigtail from a PTZ camera. As soon as I applied 12 volts to the thing, the green LED on the board lit up and started blinking! PFM, as they say.
I did notice the pins on the 28 pin microprocessor had some corrosion, so I pulled the chip and cleaned them. I will replace the socket when I get a chance.
Can anyone tell me what to use as a conformal coating on the circuit board?
 

wayneh

Joined Sep 9, 2010
17,153
I'd not bother with conformal coating. Maybe enclose the entire board if you think it needs protection.

Did your cap tester look for ESR? That's the criterion by which electrolytic caps fail first. It's not a bad policy to simply replace all the electrolytic caps on a board you're trying to fix.

Are you saying everything works fine off the battery but not on AC power?
 

tranzz4md

Joined Apr 10, 2015
310
Well, V8, other than the predictability of a rogue wave, perhaps your "anybody have experience" wording kept some of us bored surfers riding in alternate directions. ... or maybe not.....
 

Thread Starter

v-8 volvo

Joined Mar 29, 2011
5
I'd not bother with conformal coating. Maybe enclose the entire board if you think it needs protection.

Did your cap tester look for ESR? That's the criterion by which electrolytic caps fail first. It's not a bad policy to simply replace all the electrolytic caps on a board you're trying to fix.

Are you saying everything works fine off the battery but not on AC power?

I suppose you are right about the coating. A pellet stove belongs in a reasonably dry climate, not the shed it lived in for 2+ yrs.
I did test the ESR, and it passed. This was the only electrolytic on the board. Everything else was chip caps.
The stove works fine now on AC and DC modes. I just need to replace the missing cleanout plates, get the low and high fan settings optimized and install the stove.
Thanks
 

Thread Starter

v-8 volvo

Joined Mar 29, 2011
5
Well, V8, other than the predictability of a rogue wave, perhaps your "anybody have experience" wording kept some of us bored surfers riding in alternate directions. ... or maybe not.....
I wasn't attempting to bore anybody. Just reaching out for help. I want to become proficient in component level troubleshooting, instead of looking for pregnant caps, etc. I thought the Avionics class I took many moons ago would have given me that. Instead, they put my sheet metal and wiring skills to work doing installs on aircraft at the school. I probably spent less than a week doing actual bench work with an oscilloscope.
Fast forward to present day. I recently picked up a Tektronix TDS410 with a bunch of bad electrolytics on ebay (yeah, I know it's a dinosaur), but it'll be good to learn on.
For my next trick, the inverter from a Kipor 3500 watt generator. I have at least 10 hrs into this, just removing all of the potting compound with heat gun, exacto knife blade, pick, etc.
20171116_123017.jpg In it for the long haul.
Why? Because I want to learn.
 

tranzz4md

Joined Apr 10, 2015
310
I wasn't attempting to bore anybody. Just reaching out for help. I want to... .
Not at all Amigo, I refer to an omnipresent factor amongst so many regulars on these types of forums. I know that my own participation, or even lurking, here increases when my life presents me insufficient excitement to occupy me elsewhere. Had other factors not already triggered or overloaded boredom responses, I'm sure others and I would've lent our help, or vented our opinions sooner.

Best wishes.
 
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Thread Starter

v-8 volvo

Joined Mar 29, 2011
5
Not at all Amigo, I refer to an omnipresent factor amongst so many regulars on these types of forums. I know that my own participation, or even lurking, here increases when my life presents me insufficient excitement to occupy me elsewhere. Had other factors not already triggered or overloaded boredom responses, I'm sure others and I would've lent our help, or vented our opinions sooner.

Best wishes.
Thank you kindly.
 
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