Troubleshooting Electric Blanket

[Pensioner83]

Re: Troubleshooting Electric Blanket

Thank you budm, there was a white substance on the surface of the fuse which I presume was thermal compound. I cleaned it and found printed on the fuse 102C 2A 250V. I ordered a replacement fuse via ebay Thanks again.

[budm]

Re: Troubleshooting Electric Blanket

Do you have that thermal fuse in hand?
I can see it is rated at 102C but cannot read the rest of the prints on the body, you need to remove it and see. Does it show open circuit?
https://www.badcaps.net/forum/attach...8&d=1586021712

SET THERMAL FUSE:

[Pensioner83]

Re: Troubleshooting Electric Blanket

What is the electric value of an Electric Blanket thermal fuse?
Also, where can I buy a such thermal fuse?

[Pensioner83]

Re: Troubleshooting Electric Blanket

what value is the thermal fuse

[R_J]

Re: Troubleshooting Electric Blanket

Good to here it's up and working, I wish I would have noticed the missing resistor earlier, It was'nt untill I was tracing the low voltage circuit that I noticed it.

[stj]

Re: Troubleshooting Electric Blanket

103 and 1002 are the same part,
the current/wattage is not printed on them but is implied by the physical size!

[DanFen]

Re: Troubleshooting Electric Blanket

I've installed the 103 resistor and the LED is now on. Haven't checked it properly with the blanket element yet.

I still have the 1002 on order, so I'll replace with that as soon as I have it

[DanFen]

Re: Troubleshooting Electric Blanket

OK, I'll give the 103 a try later on and post feedback.

It will be fine to try, that way you will know if it is going to fix it or not.

[R_J]

Re: Troubleshooting Electric Blanket

It will be fine to try, that way you will know if it is going to fix it or not.

[DanFen]

Re: Troubleshooting Electric Blanket

Thanks for your help I'll just place the order and then update this thread when it's installed.

The 103 will likely be ok, but being smaller the wattage is likely lower so it could just open up after a while.

[R_J]

Re: Troubleshooting Electric Blanket

The 103 will likely be ok, but being smaller the wattage is likely lower so it could just open up after a while.

[DanFen]

Re: Troubleshooting Electric Blanket

I can order a batch of 100 for 81 euro cents from Aliexpress. It's just a matter of waiting and having 99 other resistors sitting there.

It should work to test, I would try and find the correct type. The original must have fallen out at one time, too bad it was'nt still in the case.

[R_J]

Re: Troubleshooting Electric Blanket

It should work to test, I would try and find the correct type. The original must have fallen out at one time, too bad it was'nt still in the case.

[DanFen]

Re: Troubleshooting Electric Blanket

Would 103 work? It's 10k, but smaller in size.

look for a couple 5k and put them in series, it does'nt need to be exact, as long as it is close to 10k, 15k would likely work as well.

[R_J]

Re: Troubleshooting Electric Blanket

look for a couple 5k and put them in series, it does'nt need to be exact, as long as it is close to 10k, 15k would likely work as well.

[DanFen]

Re: Troubleshooting Electric Blanket

My luck says not today, I couldn't find any 1002 resistors on any PC/Laptop board.

[DanFen]

Re: Troubleshooting Electric Blanket

Yes found the mechanism, when it's 0 it moves a plastic underneath them and stops the contact. Thanks for the explanation

Hope I'll find a 1002!

R2 should be a 1002 (10K) The contacts could be making connection now, but I suspect there is a slide (power on/off) or something in the case that causes them to open.

[R_J]

Re: Troubleshooting Electric Blanket

R2 should be a 1002 (10K) The contacts could be making connection now, but I suspect there is a slide (power on/off) or something in the case that causes them to open.

[DanFen]

Re: Troubleshooting Electric Blanket

Yeah I'm extra careful with that 240V thanks for the reminder

To be honest, those contacts seem to be making contact already, and there's no device that pushes them. Not sure what the idea behind it is. Tried to take a photo using a magnifying lens.

Now I see the missing resistor. I'll try to find an equivalent one from a laptop/computer motherboard. Should have done a better visual inspection! You've got a good eye

Yes I am, I also mentioned a missing R2 resistor, it likely fell off at one time and is missng which may be causing the problem

[R_J]

Re: Troubleshooting Electric Blanket

Yes I am, I also mentioned a missing R2 resistor, it likely fell off at one time and is missng which is likely causing the problem. It seems to be for the low voltage that supplies the ic. Check if it is still in the case or on the surface where you opened the case.

This is why it's not working, R2 is part of the 4 resistors that drops the ac voltage that feeds D1, which is then clamped to around +5v by ZD1 (N8). That feeds D2 and capacitor C1