A DIY repair win and a DIY question!

[Khao]

Let's start of with the DIY repair win! I had a really good pair of Sony MDR-V500 headphones that I loved very much until the little plastic hinge thing that holds one of the speaker broke. I kept the broken pair in a drawer at work and forgot about it for a couple months until a coworker had the same thing happen to an exact same model of headphones. He was about to throw them away and I asked him if I could take his broken headphones to see if I could repair it and he said sure. I took both headphones home and went to work, salvaging one part from one of the headphone to put it on the other one. It ended being way more easy than I had imagined and the result is a working pair of headphones that looks like nothing ever happened!

I uploaded a quick album of the taking apart and repairing process here : http://imgur.com/a/QRi3b but here's the important part :

Broken : Not broken anymore! -> VICTORY!


So that was a pretty good day considering this pair of headphones is worth 100$ on amazon, I was pretty pumped up and decided to attack something else that I had been slacking on : changing the bathroom fan timer. Should be pretty damn easy but my bathroom fan is actually just a timer to tell my heat exchange ventilator to turn to maximum power for 20 minutes. It's a new condo that I bought last year and I don't know a lot about heat exchange ventilators other than it moves air around and that's what my bathroom fan is hooked on. I thought the switch on the wall was a normal switch like you could install for any light or fan, but apparently it's different.

Here's what's currently installed : http://i.imgur.com/VqNTGrS.jpg back and http://i.imgur.com/onN7toD.jpg front

I tried to install a standard 2-wire light/fan timer and after turning the breaker back on, it wouldn't do anything at all : http://i.imgur.com/ze4v1xN.jpg

I don't know if I need to buy a special timer switch for my unit and I tried looking at the manual and couldn't find anything. I found the manual online here : http://ecomfort.com/PDF_files/Fantech/vhr704r_installation_manual.pdf and what I have installed is on page 12 called the 20-minute timer. On page 14 there's an electrical connection guide that shows that there's only two wires that connect the timer and that's it. That's all the info I could get. Does anyone have any idea why a normal light/fan timer wouldn't work in that case? I specifically bought one that was 2-wire and didn't need a neutral wire so I don't know why it's not working.

[Greg]

Pexsupply.com has the switch for pretty cheap:
http://www.pexsupply.com/Fantech-RTS2-RTS2-20-Minute-Pushbutton-Timer-LED

If touching the two wires together doesn't make the HRV kick into high gear then the switch must have some fancy circuitry to it that a standard switch doesn't.  I suspect if you looked at the front of the PCB of the original switch there's a chip soldered on. 

[Khao]

I JUST HAD AN EPIPHANY IN THE SHOWER THIS MORNING!

So the current timer switch that's in the wall, it's not a normal light/fan switch because it's 2 wires that goes directly to the ventilator unit. So it's very likely (I mean, I'm 99% sure) that it's not 120VAC that's coming from those wires, must be 12VDC or something like that. Also, the fact that the current pushbutton-style plate is a tiny little PCB with no bulky component makes me think that it's not handling high voltage and that it probably works off of DC instead of AC. Now I bought a wall timer swith that's made for 120VAC so there's no way it can work with my heat exchange unit. So I'm out of luck for now... I'll have to look for something else completely.

Pexsupply.com has the switch for pretty cheap:
http://www.pexsupply.com/Fantech-RTS2-RTS2-20-Minute-Pushbutton-Timer-LED

Forgot to specify but I'm not changing it because it's broken, but really because that pushbutton is so damn cheap it feels like it's going to break everytime you turn the timer on! I wanted something nicer and I figured spending ~20$ for a better wall timer switch was worth it.

[Greg]

Most AC switches will work for DC as well, so that's unlikely to be the problem. 

The problem is more likely to be that the switch is more of a little added circuitry than just a switch.  If you can find the wiring diagram for the switch and/or fan it may reveal it.  It could be as simple as a momentary switch and a capacitor, but more complex as well.