newbie mistake wrong fuse

[alloby]

Thanks I will check that cap tomorrow and let you know is it best to check out of circuit .

[Paul Moir]

Check it in circuit first.  You may see your multimeter numbers climbing up as the capacitor charges if everything is good.  There are very few (no?) cases where a capacitor is shunted by a low value resistance.
If you do get a very low resistance then think about taking it out, but I would suspect the load that this capacitor is smoothing the output of the bridge rectifier for rather than the capacitor itself.

[alloby]

I need to read up how to check it properly also can anyone tell me if a rwm 6x 22 RB57 will be ok instead of rwm 4x22 RB61 I am having trouble finding a RB61 but RS stock RB57 thanks in advance.

[alloby]

I checked the capacitor its a 47micro farad 400v and off the board it reads 52.6 micro farads and it charges up and discharges so I assume it is ok.I also reversed my leads and still read 52.6 micro farads.

[alloby]

I have just doubled checked bridge rectifier and I had a measurement wrong

The bridge rectifier reads red probe on + black probe on 1st ~ =OL
                                      red probe on 1st ~ black probe on + =0.0550
                                      red probe on  1st ~ black probe on 2nd ~ =0.0546
                                      red probe on 2nd  ~  black probe on first ~  =OL
                                      red probe on -    black probe on 2nd ~ = 0.543
                                      black probe on -   red probe on 2nd   ~ =OL
                                      red probe on 1st  ~ black probe on  - = beep or 0.001 and black probe on 1st  ~ red probe on - =beep
                                      black probe on -    red probe on 2nd  ~ = 0.0543  this is now correct
                                      red probe on +   black probe on 2nd ~ =OL
                                      black probe on +   red probe on 2nd   ~ = 0.547
I entered it wrong first time so can anyone confirm it is still faulty

[Dbhrs]

I would say that one internal diode is shorted. So it is faulty

I don’t have very much experience with this so someone may say different.


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[alloby]

Thanks I hope so I have double checked and that was the only one I had wrong

[WaveyDipole]

Yes, the rectifier is faulty. I was trying to ascertain whether it had become stressed by a short across the smoothing cap. Sounds like the cap is Ok so there must be another explanation for the rectifier failure.

[james_s]

Occasionally rectifiers just fail, I wouldn't spend much time looking for the fault. Especially in low cost Chinese gear it was probably spec'd for the lowest cost possible and may have been of questionable quality to begin with.

[ggkios]

Occasionally rectifiers just fail, I wouldn't spend much time looking for the fault. Especially in low cost Chinese gear it was probably spec'd for the lowest cost possible and may have been of questionable quality to begin with.

Hes got a jbc, starting price for one is around 500$, but yeah i sometimes bridge rectifiers fail

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[alloby]

I have ordered the exact bridge rectifier part but I cant find exact resistor rwx422 rb61 6.8ohm 7w so I have ordered Vishay RWM 6x22 rb57 Series Axial Wirewound Resistor 6.8? ±5% 7W ±75ppm/°c I am thinking they will be ok so if anyone thinks they are not suitable let me know

[alloby]

I have received new bridge rectifiers and after testing it confirms my one was faulty I am just waiting for resistors and will update when they arrive.

[alloby]

 I got my resistors in post and soldered it on board along with bridge rectifier put new fuse in and it works,I cant believe it so thanks to everyone who helped, to some it might have been an easy fix but to me I felt I was out of my depth but now I have more confidence in myself and it has helped me to think about what is happening in a circuit I feel I have learnt a lot and this forum is the reason why so again a big thank you and hope everyone has a prosperous new year.

[ggkios]

Glad it worked, hopefully it will stay this way

[Gyro]

Congratulations on the successful repair alloby.  Best wishes for the New Year.

[Dbhrs]

Congratulations and Happy New Year


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[gaborgabor]

Hi everybody !

I would like the JBC JT-2A service manual, or schematics, or circuit diagram.

Do you have it ?

Thank you for your help!
Best Regards,
Gabor

[gaborgabor]

Hi , i have a question...

What is the type number of the IC on the picture ( in the red circle )

Thank you for your help.

Best Regards,
Gabor

[Jontm]

Sorry to bump an old thread, but i had the exact same issue.
Seems like the bridge rectifier for the air is a common failure mode on these. Did not find this thread when searching for some reason, might have saved me the 250 USD i paid for a new heating element hoping that would solve the issue.
The unit i have is a JBC JT-2A hot air station.

The bridge rectifier in question is a DIOTEC B500C1500B. It has a bit unusual pinout so i have not been able to find a substitute (~+~-) Edit: Vishay VS-2KBB100 seem to be equivalent. Have ordered one as it is easier for me to get hold of than the DIOTEC B500C1500B.

Hopefully this will help somebody else having similar issues

PS: gaborgabor: The IC you are looking for is a Vishay BRT23M optocoupler. Seems like it is obsolete and out of production, but i am sure that there are some similar triac optocouplers with similar specs and package type available if you spend some time comparing the datasheet with filters on mouser/digikey/farnell/or others.

[delfinom]

Just going to throw in a comment as well for future searchers. We had a power surge that blew a bit of various equipment. The Bridge rectifier was indeed the part that failed on our JT-2A as well. I just bodged in a normal pinout bridge rectifier but just twisted the legs and expoxied them to keep em apart heh.