Question about Englander PU-CB04 diode

[fireworks]

Hi all,

I have a 25 PDVC which stopped working. The control panel does not respond when plugged in, but when it is unplugged the LEDs and the digital display flash briefly. Looking at the circuit board there is clearly a problem: at location D6 the diode is gone! It's like it just vaporized.

My question: Can someone with a PU-CB04 board tell me what *should* be at location D6 (what letters are on top of the diode)? There should be writing which you may only be able to read with a magnifying glass, such as "K44".

Thanks for your time!

 

[BackDoc]

Ssyko will give you an answer. If he isn't along soon shoot him a message.

 

[BackDoc]

I have an Englander PDV that was made in 2004. This is the board. Is this like yours? If so I may be able to help you.

 

[Ssyko]

Welcome to the forums Fireworks. unfortunately "D6" is only a designator for the board manufacturer without their crossover data we don't know what the component is.This is often done to make it more difficult to reverse engineer, or to make it more difficult to identify. It is an SOT-23 package but the designator on it (CBI) is not in any of my data books. being a 3 pin pkg it could be a voltage regulator or PNP/NPN transistor. most Zenner diodes don't use pin 2 and the board has a trace for all 3 pins so i don't think it is a diode.

 

[fireworks]

Thanks, BackDoc and Ssyko for your help. Yes, my board looks like the 2004 above (my stove is from 2008).

I was able to get another replacement board and noticed that the SOT-23 packages designated "CBI" on one board are designated "K44" on the other board (in the same locations). Does K44 mean anything or help define it? I don't know much about electronics, so I'm not sure if all SOT-23 labelled K44 are the same? Or would it be like thinking all Fords are the same because they say "Ford" on them?

The stove itself is so easy to work on (all mechanical parts) - it's too bad the electronics are so mysterious.

 

[Ssyko]

Well I stand corrected. It just may be a shottkey diode, guess i learned some more. I will pull one off my problem child and measure it and we will have that for a reference. I should just strip my board and figure out all the components. Lol

Sot-23 is just the package that it is made into. K44 is the code. Im glad you posted it. Mine is like your old one.

 

[fireworks]

Thanks very much for your time! I found a reference which indicates it is K44 = BAS40-04 ....(?)

 

[Ssyko]

Data sheet

 

[fireworks]

Cool! I can't wait to experiment! Here's an example of one for sale.

 

[Ssyko]

Just use a good temp controled soldering iron. SMD’s don’t tolerate high temp for very long (5-15 seconds).

 

[fireworks]

Success! I bought 100 BAS40-04 diodes for $5. (so, technically it cost 5 cents to fix the control board ). Soldered it in no problem and the board works perfectly. If it doesn't last I'll report back, but right now all looks good.

Thanks again for your help and the tip about soldering SMDs!