D-Link router - faulty power brick?

[sebr]

Re: Jentec JTA0302F-E for the D-Link DGS-1008D

Thanks for this information! With it, I was able to repair two similar Jentec JTA0302F-E (5 V, 3 A) PSUs for the D-Link DGS-1008D

Success here too with the replacement of this cap in the PSU mentioned above! Thanks for saving my time

[sam_sam_sam]

Re: D-Link router - faulty power brick?

Now I just have to get this thing shut. The KZE cap is just 2mm too tall. Might just drill a hole for it . I also attached some pics. Sorry if they are a bit distorted - they were taken with my cell phone with a magnifying glass in front of it to get a better macro shot.

Look and see if they have the right size in KY or what you did will also work

as far as putting the case back together I will most of the time use back tape

[stevenA]

Re: D-Link router - faulty power brick?

Thanks to all on this forum I have started to hunt down bad caps in old failed equipment. My first try and first success this evening with the 220v powerbrick for a DGS1008D!

Very simple, just a transfo, bridge and 1000UF 16v Teapo cap that was actually about 600UF and 9ohm ESR! Gave the flashing lights error.

Replaced with Panasonic FM 25V - now works fine and the switch is in the reserve.

Next up is the Apple G4 MDD PSU!

Thanks again to all for your input and motivation, and to this great site.

[momaka]

Re: Jentec JTA0302F-E for the D-Link DGS-1008D

Thanks for this information! With it, I was able to repair two similar Jentec JTA0302F-E (5 V, 3 A) PSUs for the D-Link DGS-1008D

Congrats on the fix!
Yeah, I've found that those small start-up caps fail quite often. That's why I keep a few of them in stock now.

Also, here is what my power adapter looks like now after I finished it:
https://www.badcaps.net/forum/attach...1&d=1327456835
Basically, the 10v, 1000uF Chemicon KZE cap was a bit too tall, so I drilled a hole in the case to accommodate for that. I did have some 6.3V, 1000uF Chemicon KY caps that would have fit, but I thought that this would be cooler (pun intended).
Held together with wire ties (because I don't like gluing things).

[sonic74]

Jentec JTA0302F-E for the D-Link DGS-1008D

Turns out the 25v, 47uF Teapo SEK next to the PWM controller was the culprit.

Thanks for this information! With it, I was able to repair two similar Jentec JTA0302F-E (5 V, 3 A) PSUs for the D-Link DGS-1008D

[momaka]

Re: D-Link router - faulty power brick?

i just noticed this thread,
i could have told you it was that cap,

That's okay because I didn't have this cap in stock until last month or so . And now that it's been a year later, I've learned that this circuit is actually quite different from the 2-transistor design such as the one in Bestec ATX-250 12E (thanks to the BCN forums, of course).

[stj]

Re: D-Link router - faulty power brick?

i just noticed this thread,
i could have told you it was that cap,
it's the startup cap that provides the pulse to kick the oscillator into action.

very common fault in set-top boxes & dvd players etc.
you dont need the cap for the psu to run, but you do need it to start.

so you buy some gear, plug it in, it runs fine.
the cap dry's out - but isnt being used.

soon as you unplug it that's it - it wont re-start.

[momaka]

Re: D-Link router - faulty power brick?

Well, it's been almost a year later, but I've got some results finally.

Turns out the 25v, 47uF Teapo SEK next to the PWM controller was the culprit. At first I replaced the 25v, 330uF Teapo SC on the output with a 10v, 1000uF United Chemicon KZE (8mm dia.), but that just made the output voltage awfully screwy (I would get ~1v with the router as a load and something like 6v when there wasn't a load, and the voltage would continually go up - I didn't want to blow the adapter so I didn't keep it plugged for too long to see how far it would go). Then I replaced the 25v, 47uF Teapo with a 50v, 47uF Nichicon PM and the output voltage came back to normal: 5.12v with the router as a load and 5.20v with no load.

Now I just have to get this thing shut. The KZE cap is just 2mm too tall. Might just drill a hole for it . I also attached some pics. Sorry if they are a bit distorted - they were taken with my cell phone with a magnifying glass in front of it to get a better macro shot.

[momaka]

Re: D-Link router - faulty power brick?

Well thanks to KC's method, I just opened the power brick today. Here's what I have for the output caps:

1x Teapo SC, 25v, 330uF, 8x14 (mm, dia x lenght) <--- before PI filter
1x Teapo SC, 10v, 220uF, 6x11 (mm, dia x lenght) <--- after PI filter

Like Krankshaft's power brick, mine has all Teapo caps. The date codes show they were made in 2003 (I had this router in service since 2004). None of the caps are visually bulging or leaking. And unfortunately I don't have an ESR meter so I can't test them either.
That 25v 330uF cap doesn't look right in there, though - why would they use a 25v cap on a 5v rail anyways? Lower ESR from the bigger can size?

I did test the fuse, secondary rectifier, bridge diode, and the feedback resistors with my DMM and they all seem to show proper values.
The PWM IC does not look like a UC3846, but I can't tell for sure since there's some white glue on it that won't come off easily. There's also a lone Teapo SEK, 25v, 47uF next to it. (Maybe this cap is causing a problem that's similar to the Bestec 12E with bad 5vsb design?)

Since I repeated the same test yesterday (where I left the brick to get warm under the sun after which it powered up fine again) I do think there's a bad cap somewhere that's causing this problem.
I guess I'll just get new caps for the output (with a proper rating of 10v) and pray that it works (unless someone has any other ideas or thoughts). Might even get some replacements for those Stone caps in the router. I also have two older (but nice) ATX PSUs that need new caps too, so why not buy everything at once .

Thanks for your input everyone, it was really helpful .

[Krankshaft]

Re: D-Link router - faulty power brick?

I had a D-Link DI-614 or something 802.11b router (now out of service) and the brick died.

All the caps (Teapos) checked out good so did the fuse, line rectifier diodes, the switching FET, and the secondary rectifiers.

But no output I replaced the UC3846 or something like that (it was a very popular PWM controller IC) and it came back to life and worked until I took the router out of service 3 years later.

I seem to find that usually when a PSU won't come up and the fuse, line rectifier, and FET is fine. It's probably either the PWM IC or the startup resistors.

[Scenic]

Re: D-Link router - faulty power brick?

had the same problems on a D-Link DI-604

PSU died. no output at all. and no internet
was a 5V 2A though (not 2.5A).

opened it up (quite tricky).. all caps splattered their innards all over the place.. yuck.. -> trash..

replaced it with a different PSU (i guess it came from a Casio digicam which is loooong gone.. PSU has the same rating though)
fitted the original cable which goes to the router.. (the casio PSU had screws *yay*) and replaced the caps.. just in case..

works fine ever since (1 1/2 years ago)
caps in the router have been replaced at the same time (with pannys)..

this thing is in service here since 2004.. 24/7

[severach]

Re: D-Link router - faulty power brick?

Clamp one half of the shell in a vice to stress the glued joint. Tapping and prying will crack the glue. Flip it over to stress the glue in a different direction. Sometimes I put them back together with a zip tie.

I've fixed quite a few routers by replacing those small caps. Don't overlook them with your ESR meter. If the power led is controlled by the CPU then the absence of a power led may be misleading.

[lucky13]

Re: D-Link router - faulty power brick?

Output: 5.0v, 2.5A, 20-30VA

What is this?

You most likely will destroy the casing to force it open. There is no other way. Once you repaired it, you can use hot glue to put the casing back together.

This is a commonly used 5v brick that is also used to power many other small devices. So, if you cannot open/fix it, you can look for other ones having the same dc plug.

[kc8adu]

Re: D-Link router - faulty power brick?

place knife edge in seam.strike with hammer.repeat on other side.replace caps.glue shut with ca.
at&t dsl units have a similar unit.i can fix one faster than the at&t servicer can be dispatched even if he is next door at the titty bar having lunch.
oh and replace at least all the stone caps.and the teapo .panasonic fc is a good choice as these run hot.fm will do ok too.

[momaka]

Well, after the electricity went out for an hour yesterday after a storm, my D-Link DI-614+ router would not come on (no power at all). I'm not exactly surprised though, since it had the same problems in the past too - if you unplug it and plug it in, it would take a while before any power came on and sometimes it would need to be plugged and unplugged at least a few times before it came on. The router itself has Stone caps and a lone Teapo SEK. I know the Stone caps aren't exactly good, but at least the router should power on and it doesn't.

Since this seemed more like a power adaptor issue to me, today I decided to check the power brick with my DMM. When I plugged it in, there was very little voltage coming out (around 0.5v). Plugging and unplugging it a couple of times would bring the voltage up, but nowhere near the specs on the label (see below). I even tried putting a 90mm 0.23amp fan for a minimum load while measuring the voltages. Still nothing but very low voltage.

Judging by the size, this is a switch-mode power brick. Here's the info that's on it:
Shang Ming Electronic Co., LTD.
Model: SMP-T1178
Input: 100-120v, 0.5A, 50-60Hz
Output: 5.0v, 2.5A, 20-30VA
UL E220699 <--- it doesn't lead to anywhere when I Googled it.

Because this is a SMPS brick, I decided to do one more test on it - I left it under the sun to cook a little. 30 minutes later when I plugged it in, suddenly there's power! I tried powering the fan above and the router and they both powered up fine. Voltage was 5.20v with the fan. After I left the power brick to cool down, it won't produce any power again...

So what do you all think, a faulty output capacitor maybe? According to my tests, that's what it should be since the power brick came on when it was warm, but not when it was cold.
More importantly, any idea on how to open it - without using a hammer or a saw, that is. There's no screws anywhere, not even under the label. I'm guessing it's probably latches on the inside, but the thing is shut very tight. Any chance to open it at all?