Error on Thermistors

weput

@dc42 Thank you.

I've seen that... unfortunately with this covid-19 lockdown i assume i'll have to install and run on 8 bits for a while.

dc42

In the UK at least, the major component distributors are still shipping components. What country are you in?

weput

@dc42 said in Error on Thermistors:

In the UK at least, the major component distributors are still shipping components. What country are you in?

Panama.

dc42

If you have a resistor with a value in the range 2 to 10 ohms, you could temporarily connect that between VSSA and ground instead of the fuse. Space it well off the board, because it will burn up if you get a short between VSSA and VIN - which may be what caused the VSSA fuse to blow.

clearlynotstef

Personally I used a tube fuse and little holder thing, but you could even solder directly to the fuse if you could get one of them. There's gotta be someplace still selling standard fuses online near you

https://www.amazon.com/dp/B00X7B6FPI/ref=cm_sw_r_em_apa_i_TyFIEb1C2DN29

https://www.amazon.com/dp/B00VLBAF84/ref=cm_sw_r_em_apa_i_bFFIEbQQWNZKN

weput

ok guys...

we are still in lock down so no luck to getting the fuse or the resistors...

(im fine as i have another printer running...)

Anyways, I'm thinking on breaking one of those x-mast decoration light cords (the ones that comes with like 150 small bulbs wired in series) to use one incandescent bulb... its a low resistive lineal load and if something happens it should manage the power by emitting light...

.,.. then i recalled i have a few small led's laying around... technically the same principle with the 0.7v drop.... anyways,

here im asking.. what do you think?

is there not a gas station or anything like that you can get a fuse from? (they might not have very small values though, but might for motor cycles)

weput

@bearer said in Error on Thermistors:

is there not a gas station or anything like that you can get a fuse from? (they might not have very small values though, but might for motor cycles)

the smaller they had was 10 amps... the fuse should be rated for 100mA... max 200

way too much current.

weput

Just to let you know guys (assuming you care)

i pull out a potenciometer from my electric guitar... so the printer is going to be running soon.

dc42

@weput said in Error on Thermistors:

ok guys...

we are still in lock down so no luck to getting the fuse or the resistors...

(im fine as i have another printer running...)

Anyways, I'm thinking on breaking one of those x-mast decoration light cords (the ones that comes with like 150 small bulbs wired in series) to use one incandescent bulb... its a low resistive lineal load and if something happens it should manage the power by emitting light...

.,.. then i recalled i have a few small led's laying around... technically the same principle with the 0.7v drop.... anyways,

here im asking.. what do you think?

The incandescent bulb should work.

weput

@dc42 (y)

weput

funny...

i was about to place the fuse... but because i had to remove the cables i had fro the potensiometer...

... checked the continuity and happens that the original fuse has continuity.

weput

stupid question...
what is the actual resistance i should measure between vssa and gnd?

the thermistors are oscilating way too much...

@weput pretty much 0, single digit omhs at most.

weput

my small ohmmeter is a cheap old analog type...10ohm and 1k selector...

resistance was 8~9 ohms if this is ok.

I'm leaning towards to replace the fuse.

@weput said in Error on Thermistors:

8~9 ohm

datasheet for the replacement part suggest 0.6 to 2.5 ohm, but early boards could use a different part.

do you get a 0 reading if you touch the probes together?

weput

@bearer said in Error on Thermistors:

touch

let me check...

do you want me to measure the resistance on the thermistor connection?

by the way, this is the temp reading i have.

@weput said in Error on Thermistors:

do you want me to measure the resistance on the thermistor connection?

no, just measure the resistance from the red probe straight to the black probe, to check if the meter will give you a reading of 0 when the resistance should be 0.

weput

the ohmimeteris fine.

I'd expect a larger value for it to be the cause, on the other hand if it worked with the workaround (lightbulb or resistance?) then the fuse is what remains - if you have the spare then just replace it.

(OR solder the new on top of the old, should be less risk of damage to the board)