Help with a non PC PSU

[silencery]

Hi everyone,

New to this community, but I'm hoping someone can help?

Long story short, we recently had an extended power outage. For whatever reason, at least 3 dozen households in our area experienced thousands of dollars worth of electrical damage once the power came on. In our case, we lost the water heater, dishwasher, smoke alarms, and dozens of smaller electronics.

One of the smaller broken appliances I'd like to repair is a floor fan. This model was specially imported from overseas and can't be found here, so it's pretty much irreplaceable.

The PCB looks good physically, but I'm testing the traces. It looks like I need to at least replace the blown ceramic capacitor (circled in the image) and the square fuse to the left of the capacitor. Can anyone help suggest a way to figure out the size of capacitor?

Thanks in advance!!

[R_J]

Re: Help with a non PC PSU

It's not a capacitor, that looks like a protection mov (V1), carefully clean off the brown glue from the side so you can read the number. It is likely rated at around 130v, also measure the diameter
The power supply will operate without the mov in place (but without the surge protection) so you should be able to test if it works.
If it is a 10mm it could be a 10D181k or 10D201k for 120vac input. If this is a universal voltage power supply the mov could be a S10K300 for 85~265vac input

[silencery]

Re: Help with a non PC PSU

Ah, thanks so much!!!

I'm looking for my micrometer now, so i'm not sure about the diameter, but yes, eyeballing it, it does seem to be 10mm.

The label is really burnt, so I can't pull anything legible off it, but I've attached some photos anyway, just in case.

The specs on the device do state only up to 120VAC input.

I will try operating the power supply without the mov.

EDIT: Oh, now with the aid of the blown up image, I do believe I can make out the letter VOE and 745 +

[stj]

Re: Help with a non PC PSU

it's the upper number, i can see a 2
it probably saved the psu, too bad they didnt put heat-shrink sleeving over it to keep the bang contained.

[silencery]

Re: Help with a non PC PSU

They did have heat shrink sleeving over this component, and it was glued to the PCB. I just pulled it off to get a better look

A few more clues and some good news!

• The component is 8mm in diameter (my eyeball ruler needs calibrating)
• The PCB is silkscreened with a symbol that looks like a backwards "Z" with a line through it. Haven't seen this one before.
• Thanks to R_J's guidance, I found the board does indeed work without this component in place. I bypassed the burnt fuse for testing and it's putting out 24VDC perfectly!

I already have the replacement fuse on order, and I'm very happy to get it running again. I had thought it would be a lost cause. Of course, restoring back to factory spec would still be preferred, so any help would definitely be appreciated

[stj]

Re: Help with a non PC PSU

the bigest mov you can fit!

[R_J]

Re: Help with a non PC PSU

I agree, install the a larger diameter one if you can. 10mm

I suspect the original is made by JOYIN and is likely a JVR07N241K or JVZ07N241K

[silencery]

Re: Help with a non PC PSU

Man, you guys are amazing. Thanks so much for your help!!!

[PeteS in CA]

Re: Help with a non PC PSU

That MOV plus the many damaged appliances in your area mean that the area had a significant electrical surge, either just before power went out, or right after it was restored. The fuse is between the AC input wires so that when the MOV fires, it blows the fuse.

If you have any power strips with surge protection that were plugged in when all that happens, their surge protection MOVs are also probably damaged.

[silencery]

Re: Help with a non PC PSU

Yes, really good point. I've been concerned this surge caused a lot of unseen damage. For our neighborhood, many homes are still assessing all the damage (broken outlets, no hot water) many days after the outage.

Aside from replacing UPS and surge protectors, any suggestions for precautions to take?

[stj]

Re: Help with a non PC PSU

you could fix a ups, they will have mov's in them.