diyrebel
@diyrebel@lemmy.dbzer0.com
- Submitted 3 days ago to askelectronics@discuss.tchncs.de | 3 comments
- Comment on Does it make sense that a fridge relay start winding would get only 20 volts from the thermostat? 2 weeks ago:
A better test may be to forcibly energize the relay so it closes.
By this, I assume you mean to hotwire the relay. I was actually planning on that. But then when I saw that the thermostat was sending 20V to what seems to be ultimately the start winding pin, it triggered me to first start this thread.
I am confused because I would expect there to just be two wires going to the relay. I believe it’s the relay’s job to break that into 3 pins. The relay has a connection that clearly goes to the common pin, which is the load. There is also a connection marked “N” for neutral, which goes to the run pin. The voltage across those two pins (coming from the thermostat) is 230v. So far, that’s all expected.
But then there is a 3rd wire from the thermostat going to (what I think is) a line that ultimately leads to the start pin. There is 20V across that and the load. So how do I hotwire that? I would obviously connect the load to and the neutral wires to their respective inputs, but I don’t know if it’s safe to jump the neutral to that 3rd input (which I think is the start pin). There is like ~54 ohms between the start and run inputs on the PTC relay.
- Comment on Does it make sense that a fridge relay start winding would get only 20 volts from the thermostat? 2 weeks ago:
Is there a step-down transformer anywhere?
I doubt it… unless that’s something we would expect to find in a fridge? I see no big coils. There are also no fans on this fridge. No start capacitor either. The YT videos I saw do not correspond well with this. There is no freezer→fridge damper either. There are coils in both.
The thermostat should be easy enough to test - you know where the supply is, and which wires energize this relay. Test voltage at the relay when the thermostat closes.
I cannot easily remove the thermostat… hard-wired in, otherwise I would try putting it in a working freezer then check that it closes. But OTOH that test is perhaps not useful since the problem is not continuous running. The problem is not running at all.
I can’t access that wiringwork page, but I would expect current and voltage to both be zero when the thermostat is happy. In any case, I appreciate the feedback.
- Submitted 2 weeks ago to askelectronics@discuss.tchncs.de | 5 comments
- Submitted 2 weeks ago to fixing@slrpnk.net | 0 comments
- Comment on My Beko washing machine must be junked because it thinks the load is imbalanced? 2 weeks ago:
I think I’m done buying washing machines. I have been hand-washing my clothes for over a year now. If I buy a machine, I become part of the problem… I become part of the financial support system for the scandals.
I can’t quite tell from what you describe if Samsung did something wrong. It seems reasonable to have a sensor. But if it’s too sensitive and gets false positives, then indeed that’s junk.
I think nothing is worse than what I experience with Beko: secret codes that force us to trash machines where all components work, but the manufacturer will not reveal the secret. Nothing is more infuriating.
- Comment on My Beko washing machine must be junked because it thinks the load is imbalanced? 2 weeks ago:
Controller boards tend to cost about as much as a complete working 2nd-hand machine.
I have not checked yet for the machine at hand, but my other Beko which is also trapped in an error state and the parts shops can no longer get the controller board. Beko themselves cannot get one either. And I must say, replacing hardware to change the state of software is not an acceptable solution for me.
A jumper, I can handle. But I need the information. That’s all I need is information. Which pins need a jumper?
- Submitted 2 weeks ago to fixing@slrpnk.net | 4 comments
- Comment on My Zanussi fridge must be junked because (IIUC) a simple relay switch went bad? Are my resistance readings good? Is there such a thing as a universal fridge switch? 2 weeks ago:
I appreciate the effort. That manual is for a model beginning with ZFC, and mine is simply Z… I tried anyway, despite generally refusing to deal with the manual cartels. I could not get past the reCAPTCHA forced by manualslib. But I doubt it would help anyway. What I need is a service manual containing the resistence measurements. User manuals never have that info. The slightly different manual that I have (ZD 19/4 D) does not have anything useful.
Regarding fixpart.co.uk, I just get 403 forbidden on that site.
I’m not sure to what degree it helps, but if your problem with acquiring a part is geographical in nature I’m in Ireland, and am happy to get and mail the part for you if it is available in either EU or the UK. Good luck and keep us posted!
I appreciate the generous offer! I’ll keep that in mind but I will first try to diagnose more precisely which part I need… whether it is the relay or the thermostat. Then I will try to find it locally. If it’s the relay then I’m probably toast. But I might see if something universal can be rigged up.
- Submitted 2 weeks ago to chemistry@mander.xyz | 3 comments
- Comment on Help me decode this Beko error code 3 weeks ago:
oh wow! That looks close for sure. Great find… I’m sure it will be useful. I’ll look at it more later today.
Thanks!
- Comment on Help me decode this Beko error code 3 weeks ago:
Thanks!
Indeed I need the heavily protected service manual… but nonetheless I’m still happy to have the correct user manual.
- Submitted 3 weeks ago to fixing@slrpnk.net | 2 comments
- Comment on Help me decode this Beko error code 3 weeks ago:
Is there any noise to speak of, like the door lock clicking?
No noise. It’s completely silent. So I disconnected the garden hose because if it does not even trigger the water inlet solenoids then it does not help to maintain water pressure for future tests.
User manual seems to be pretty readily available online,
I’ll have another look, but I generally ignore the dedicated third-party manual websites as they are just time-wasting enshitified rabbit holes. If I am convinced a service manual is in one of those walled gardens, I might go through all the boot licking hoops and do a dance to get it.
In any case, I appreciate your feedback.
- Submitted 3 weeks ago to fixing@slrpnk.net | 7 comments
- Comment on repair cafes are oriented to “give you fish”, rather than “teach a man to fish” 2 months ago:
www.repairtogether.org is involved and there are links that give locations and times, though I don’t have it at the moment.
- Submitted 2 months ago to fixing@slrpnk.net | 9 comments
- Comment on Questions on how to connect a PC to a washing machine (USB→TTL serial) 5 months ago:
When I meter gnd against 5v on the adapter, I get 5.15v. So both the adapter and the DMM are fine.
I heard that connecting two DC supplies together would have no problem if they both output exactly the same voltage. Of course we would never have an exact match, but the only strain on either side of the connection would be from the difference between the 5v from the adapter and 5v from the washing machine. So I’m tempted to conclude the serial port was sabotaged at the factory.
- Comment on Questions on how to connect a PC to a washing machine (USB→TTL serial) 5 months ago:
I had the two 5v pins connected (from 5v on the adapter to the 5v pin on the washing machine). I had it that way for maybe 10 or 15 min until I was told not to. Now I wonder if I damaged it because when I meter the 0v against the 5v, there is almost nothing there. Did I damage it, or did the manufacturer disable the serial port before it got to me?
- Submitted 5 months ago to fixing@slrpnk.net | 6 comments
- Comment on Washing machine PCB has a USART port. Do repairers use that? 6 months ago:
I appreciate your insights but struggle to reconcile the following with what others say (youtubers and folks in an electronics chat room):
I doubt many people use eeprom to save any kind of error. … It is far more likely that the script is just a state machine and is reaching an error state because of some missing or bad signal that it needs to continue running the script.
I asked EE folks how would a controller board sense a fault? Does the controller take resistance measurements on the components? The answer was “highly unlikely - that would be far more sophisticated and costly than what would be realistic in a domestic washing machine”. They said fault detection is based on logic. E.g. if the tacho sensor does not have increasing feedback despite increasing power to the motor, then the controller can detect from that that there is a fault. Or if the water has been filling for a long time and the pressure sensor is not detecting a pressure increase, the machine would know from that activity that the inlet valve has a problem.
You seem to suggest that the script reruns from a clean state every time and that a “bad signal” would be re-detected each run, which then implies that the machine would repeatedly attempt to fill with water, tumble, drain, etc. But that does not seem to be what I am seeing. The machine will be powered off & unplugged for days, and when powered on it instantly flashes that there is a fault (which is likely only known after attempting to run the various components). This is consistent with what a Youtuber said: the machine (not my particular model but speaking generally) stores the fault code. From there, the machine is trapped in that state until the error code is cleared by pressing a secret sequence of buttons.
Some leaked tech docs for a different model (same make) mentioned that if a fault occurs 8 times, it then becomes stored in memory. This seems consistent with what I observed. I repeatedly attempted to run the machine. Not sure how many times. Motors would run, failure hits, and then it quits. After doing that so many times (which I regret), the behavior changed. Now the machine will not even attempt to run because it is apparently trapped in an error state.
So everything seems to point to the error code being stored in EEPROM (which I believe is embedded in the ATmega8L chip). And not just the error code but apparently a count of failed attempts to run a program.
- Comment on Washing machine PCB has a USART port. Do repairers use that? 6 months ago:
I don’t intend to modify the program. I am just looking to reset the state of the software to get it out of the fault state.
Normally that can be done by using the buttons to enter a secret combination code to:
- enter diagnostic mode
- run various functions/cycles which normally run as part of a program
- see the error code
- reset the board
When the software detects a fault (such as a broken pump), it saves the error code. Then if you fix the pump, the software doesn’t know the pump has been fixed. So the board has to be reset to clear the error code.
The button sequence codes are secret and known only to the manufacturer. They are very protectionist. In Europe, law requires them to make the codes available to other 3rd party technicians – but only in the 1st ten years and they can also charge a fee. Consumers get no access under any circumstances.
My thought was theoretically a pro independent repair service would not want to pay every manufacturer for the secret info for every model they repair – so perhaps they would attach to the USART serial port and have a way to see errors and reset the board. But if it’s as you say, then the USART is disabled and useless to repairers. Which means I’m stuffed because I cannot buy a replacement card for my machine.
If the serial port is not disabled, you conjecture that it is likely a read-only non-interactive mechanism. That still may be useful. I was able to find the secret button combination that is likely giving me an error code which I can guess the meaning of based on leaked docs for other models, but I’m not satisfied with that. I would be useful if I could get more verbose or supplemental info about the error state.
- Comment on Washing machine PCB has a USART port. Do repairers use that? 6 months ago:
The MCU is an ATmega32L, which seems to be well documented. I was able to fetch a 300+ page document and a 12 page overview of the specs.
- Submitted 6 months ago to fixing@slrpnk.net | 8 comments
- Comment on trying to test washing machine motor; saw a white flash, voltage dropped, what happened? 7 months ago:
I appreciate the guidance. But I think I can rule out insulation breakdown because I just removed the cover to the tacho generator and the ring magnet was broken in two pieces.
- Comment on trying to test washing machine motor; saw a white flash, voltage dropped, what happened? 7 months ago:
Thanks for the feedback! So I guess I should buy a megger. Wow… not cheap. I think I see these at local 2nd hand street markets. I often thought “what strange multimeter… so few functions” but I didn’t realize what I was looking at. I will look for something that dials “500V” and has fewer modes than a multimeter, and ideally a “MΩ” printed somewhere although it looks like they won’t all print that on the device.
I suppose I could try to bring the motor into an appliance repair shop and pay them to test it with a megger.
As far as diagnosis of the whole machine-- suppose it’s true that I have an insulation failure. The control panel LEDs light up correctly when powered on, then when I try to start a program the start button just blinks. Does it seem viable or likely that faulty insulation would cause the controller to behave that way? I get the impression that the blinking LED means the controller detected an unspecified fault of some kind & refused to continue, which tempts me to think that the controller is functioning correctly – unless it’s a false positive of a failure.
I really want to avoid replacing multiple major parts because I don’t imagine I can return special ordered parts.
- Comment on trying to test washing machine motor; saw a white flash, voltage dropped, what happened? 7 months ago:
Right but I think that safety capacitor (SC) is the last thing I care about. IIUC, I could perhaps even simply bypass the SC because it’s merely improving the power quality. It’s not worth buying an SC if I fail to fix whatever else is broken. If I could get the machine working, I could then of course consider replacing the SC as a final protective measure.
The task at hand is testing every essential component of the washing machine, starting with the motor and tacho. I would like to understand what happened with the SC and motor though. Did I wire the motor wrong which caused the SC to flash and produce bad output for a moment? I don’t want to repeat that. I could power the motor directly without the SC, but if the motor is doing upstream damage then I guess I wouldn’t want my breaker box on the chopping block.
- trying to test washing machine motor; saw a white flash, voltage dropped, what happened?piped.manganiello.tech ↗Submitted 7 months ago to fixing@slrpnk.net | 7 comments
