Trying to bring a car boot Joggler back to life - short somewhere?

[jkn]

Hi All
I blew £3 on a Joggler at a Car boot sale at the weekend - no PSU but I have a surfeit of those...

On powering it up, not a lot happens, so I've dismantled it to investigate a little further.

I think there must be a short somewhere - the input voltage drops way down from 5V when it is plugged in. The components in the PSU area are getting a bit warm. LED D5 is flashing, somewhat intermittently.

Any thoughts about where to go from here?

Cheers, Jon N

[hawsey]

Have you another on to swap bits with ? The screen is probably ok .
Is there any sign of life on screen .

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[pete]

There is a fuse near by the 5VDC input on the motherboard. Typically if the fuse is burnt up then you see it and there will be no power to the main board.

Maybe the fuse shorted to ground. Take pictures of the board near the 5VDC input (both sides) just for some extra eyes.

I have replaced one fuse many years ago. Thinking I posted pictures maybe here on the forum.

[jkn]

Hi Pete

There is a fuse near by the 5VDC input on the motherboard. Typically if the fuse is burnt up then you see it and there will be no power to the main board.

Maybe the fuse shorted to ground. Take pictures of the board near the 5VDC input (both sides) just for some extra eyes.

I have replaced one fuse many years ago. Thinking I posted pictures maybe here on the forum.

Thanks for your reply. Typically, after (!) posting I found a few of the previous posts on this subject.

FWIW I am not convinced that it is a fuse that people have been replacing. I have taken a photo (different for the O2 joggler and for the OpenFrame one that you replaced, I think).



Looking at the relevant area of the PCB, going from right to left we seem to have:

- C379 - small capacitor
- ??? black device no-one seems to mention. It is not fitted on some of the images I have seen here. It does look to possible have been damaged.
- C376 - small capacitor
- C515, perhaps? - medium sized capacitor. People seem to have removed this successfully, but I do not believe this is a fuse or a zener
- C??? - sorry, can't read it on this image - large capacitor. Given the 'C' marking nearby I don't believe it is this component either
- (power leads coming in)

At the moment I am more likely to think that it is the black component - a zener across the 5V power rail which has shorted? - but is seems strange that no-one else has fingered this part.

I tried to buzz things out last night but it was a bit difficult to draw conclusions at that time of night. I will try again tonight and maybe get a microscope on that part to see if it can be better identified. I still haven't seen anything on the Joggler that looks like a fuse to me...

Puzzled and with thanks, Jon

[jkn]

Well, curious...

I took a closer look at the black device:



and it looked pretty suspect. In fact it crubled away easily under the slight pressure of a pair of pliers ... and now the Joggler boots up fine!

So, two thoughts:

- why is no-one mentioning this as being the zener? eg the image in this thread: viewtopic.php?f=4&t=426&start=20#p23141 shows the same
PCB as mine but with a different component (a cap, I think) marked as being the zener, and 'my' component not shown. Just an editing mistake?
- I would like to replace the faulty part - any thoughts as to a good value & rating to fit? I think I could see the markings "AE M99" on the faulty part, but that doesn't yield much in a web search...

Anyway, quite pleased to have added for my collection for not very much money...

[hawsey]

Wow , well done , I would be tempted to leave it alone now ha ha .

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[jkn]

Hi Hawsey

Wow , well done , I would be tempted to leave it alone now ha ha .

Yeah, I know what you mean ... I do have some skills in this area though. It'd be nice to get things right. and maybe add to the body of knowledge about these little beasts

[hawsey]

Good luck , I had a scan about as well and couldn't find it either . Maybe a data sheet or something is what we need .
I have a Joggler which I broke myself by plugging in the wrong supply years ago I might dig it out as well to see if I can fix it .

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[pete]

Great news jkm.

Yes what I replaced was a zener diode and I called it a fuse. Apologies. It was burnt to a crisp. I do not recall now what it was I replaced it with.

That said just install a similarily sized zener diode rated at ~ 5VDC and low watts (well like 1 watt).

[jkn]

Hi Pete

Great news jkm.

Yes what I replaced was a zener diode and I called it a fuse. Apologies. It was burnt to a crisp. I do not recall now what it was I replaced it with.

That said just install a similarily sized zener diode rated at ~ 5VDC and low watts (well like 1 watt).

OK, well that clears things up a bit - thanks.

I am probably going to find some 5.6V Zeners of a similar size on eBay and fit one of those. The SOD-123 package diodes seem to have a rating of around 0.5W

[pete]

Yes here switched mostly to using 5VDC POE Power splitters (TP-Link) for power to the Jogglers.

The one I fixed was a purchase here for $5 USD. Still using it today.