help repair router..no respond for power

[pharaon]

no respond for power the front led dos not light at all...i tried to re-solder those tow blue capacitors in hope it will work but nothing..hope you can guide me to find out the issue and fix it

 

[Gryd3]

I don't see any physical faults.
Have you confirmed the AC-DC Adaptor is working properly?

 

[pharaon]

Have you confirmed the AC-DC Adaptor is working properly?

yes it work fine and the out put is 13 DCV

 

[73's de Edd]

Sir pharaon . . . . . . .

This one may be bordering upon the impossible, unless its power generation / distributiion related.
Seems to be about a 2005 vintage unit . . .right ?
First check the white ceramic cased rectangular fuses within the left YELLOW rectangle.
Confirm, if I am correct,that the other YELLOW box is being a smaller fuse . . . . .could, instead, be a monolithic block capacitor instead . . . . since this is not being your usual excellent picture.

Isn't this a 1 in and out loop, providing 4 drops for distribution ?

Pass us the Mystical Magical Power converter numbers on the case of the LIME GREEN box and its associated IC in the PINK box.

Power up the unit and expect your power pack input DC voltage to read also at the first RED-BLUE electrolytic capacitor.
Also see if, or how many of the RED circlecapacitors read a DC voltage being across them.

That's being a start for now.

73's de Edd


(Probably . . . . . . .Soon to be censored, by a censor )

 

[davenn]

Sir pharaon . . . . . . .

This one may be bordering upon the impossible, unless its power generation / distributiion related.

I completely agree, this is about right, chances of repairing it beyond a basic power fault is highly unlikely


Dave

PS is this the router that was connected to the PSU from your other thread ??

 

[pharaon]

First check the white ceramic cased rectangular fuses within the left YELLOW rectangle

they are working fine

Confirm, if I am correct,that the other YELLOW box is being a smaller fuse . . . . .could, instead, be a monolithic block capacitor instead . . . . since this is not being your usual excellent picture.

it's capacitor

Isn't this a 1 in and out loop, providing 4 drops for distribution ?

what do you mean?

Pass us the Mystical Magical Power converter numbers on the case of the LIME GREEN box and its associated IC in the PINK box

i don't know which LIME GREEN box or how to get the Mystical Magical Power converter numbers..i toke more pic hope it will help

i notice some thing
when i turn it on the power led light in red instead of green for little period of time before it get off and this thing inside the red circle get extremely hot and smell like burning

Power up the unit and expect your power pack input DC voltage to read also at the first RED-BLUE electrolytic capacitor.

C1 = ±4.2
C2 = ±3.7

Also see if, or how many of the RED circlecapacitors read a DC voltage being across them.

C3 = ±4
C4 = ±4
C5 = ±3
C6 = ±1.4
C7 = ±3
C8 = ±3
C9 = ±1.4
C10 = ±2.9

the last image for the red light that last for few seconds before it dim

 

[73's de Edd]

Sir pharaon . . . . . . .

My:
Isn't this a 1 in and out loop, providing 4 drops for distribution ?
Your:
what do you mean?

I can see it better now, using your added pictures . . . . . what I meant, is that there is either a DSL or CAT-5 connector that comes into and out of connector CN3. While your router makes its 4 outputs on connector CN2.


Your good set of pictures revealed a lot for the "reading" of the board this time around.
Your 12----13 Vdc power supply voltage comes into the board at the power connector and is supposed to be initially, further filtered by the C1 E-cap, with the supply then routed down to the the C2-C3-C4 area.

I can now read the number on the 5 leg power IC I queried about, with it being an AP 1501 33.
That would be a 3.3 V @ 3 A buck converter power IC, which should be OK, as its just not presently receiving its minimum DC voltage input.

Looks like the lightning hit that damaged the power supply block, which you just repaired, ALSO carried itself into this board and "crunched " the black, surface mount, surge protector . . . . .item SP2.

It is a metal oxide varistor that originally was rated in the 18-20 volt range, but the lightning hit has damaged it, and it now THINKS, that it is being a 4 volt ZENER diode.

Here is info on that product, so that you can further Edd-i cate yourself on the device.

http://www.tawelectronics.com/sfi/sfi-catalogue2005-1.pdf

You will need to replace SP2, to get a same type of protection, in the FUTURE.

For the present, I think that you just might look outside to see that no storm clouds are being overhead and then come in and unsolder that defective SP2 unit from the board.

If you then power up the board again, I suspect that all voltages will come up to normal, and with input at your CN3 connector, you will see all of the winky-dinky-blinky LED activity lights.


73's de Edd

 

[pharaon]

You will need to replace SP2, to get a same type of protection, in the FUTURE.

The problem is i don't think i can find such part locally.. Need to put something else which can do the same like fuse or zener diode
What do you suggest. I'm sure i can find such part locally. I have an old pc power supply but i doubt i can find same part in it

Also to remove it do i need hot air or just regular solder iron

 

[73's de Edd]

Sir pharaon. . . . . . .

In pulling that part, one could expect a GOOD amount of heat required, as the right connection to the massive free foil area is going to pull away quite a bit of any applied heat.
If my task to do, I would probably try using my FLUSH cutting diagonal pliers to clip the right sides tab connection to the device.
(Cave Man 101 . . . .fingernail or toenail clippers might also successfully do that task )
Then, the left side of the device looks to be having ABSOLUTE MINIMAL access to it.

Once the right side connection is clipped, I would take the tip of a standard screwdriver to place constant /continual downward pressure on the remaining left tab.
Slightly pull up on the free right half of the device, to see just how much free upward movement can be safely be made, since you DON'T want the boards copper foil tab being lifted and being pulled free from the board.
The applied screwdriver tip gives you some degree of insurance of that not happening.
Hopefully, you will then find that the tab will safely lift up enough so that you can press it down again, lift it up again, press it down again . . . . . .and after about 76 1/2 operations, you will find that the tab will snap from metal fatigue, and that you will then be left, with the then freed device, in your fingertips.

Full access for tab remnant removals and solder cleanup should be easy then.

Flush Cutters:

Secondary thoughts were:

• 1. . . Covering the mass of the board with an aluminum foil blanket with a micro hole over the part, for selective hot air application.

• 2 . . . The same procedure in covering up ALL of the board and leaving a micro hole for part access and then the use of a micro cut- off wheel chucked in a DREMEL tool and then use micro touches to cut up the right tab . . . . . .but the left tab would still require the flex procedure due to its inaccessibility of the DREMEL tools wheel.

Or a soldering iroh would "scorch " some of the parts around it.


If you can't get the same part, you would have to go old school . . . .before these devices ever came on the scene . . . . .and use an 18V 1 watt Zener diode .
Negative terminal to the ground plane and + terminal to the supply voltage side.


ASIDE COMMENT:

In looking at the parts AVAILABILITY situation in Cairo or Alexandria, I can certainly see what you mean, with their only offering being two TEMPERATURE sensing devices. And minimal other components.

http://store.fut-electronics.com/

Plus there seem to be two other stores at RAM and El Gammal, but VERY limited also, and high priced, so some say.
Looks like cast off electronics being harvested might be your strongest source of parts but still not giving you some special parts .
Looks like you might be an elite person there, if you repaired electronics, and IF you could get the required repair parts.



73's de Edd

 

[pharaon]

and use an 18V 1 watt Zener diode

why 18 V shouldn't it be 12 V like the input or even 4 V like the converter power IC

AP 1501 33.
That would be a 3.3 V @ 3 A buck converter power IC

 

[73's de Edd]

Sir pharaon. . . . . . .


That devices PURPOSE is just for OVER VOLTAGE protection, you never want it to even be conductive UNLESS the equipment is receiving OVER VOLTAGE, like the regulation portion of your power block failing or a LIGHTNING HIT.
A 15volt 1 watt zener also might be permissible, since that still seems to be above your 13 VDC.
Right now , though, a fast power up without anything ,would let you know if the rest of the board is being OK.

AP 1501 33.
That would be a 3.3 V @ 3 A buck converter power IC

Meaning, when you pull that bad part to get a FULL 12 VDC into the AP1501 it should work.

As it is, the mere 4 VDC now available, is not being enough to let the part work..



73's de Edd

 

[pharaon]

That devices PURPOSE is just for OVER VOLTAGE protection, you never want it to even be conductive UNLESS the equipment is receiving OVER VOLTAGE, like the regulation portion of your power block failing or a LIGHTNING HIT

ok thanks i got it

i have a zener diode but how to check it's volt

 

[73's de Edd]

Sir pharaon. . . . . . .

FIRST see if the board works, when you remove the mentioned bad part, then worry about identifying a proper Zener, for later.

http://www.learningaboutelectronics.com/Articles/How-to-test-a-zener-diode

Use the very last test circuit at the very bottom, but you would need 2 series batteries if the zener voltage is greater than about 18volts , or even more batteries or a separate power supply if the test voltage required is being even greater.
The series inserted 1K resistor / currrent limiter, is being a must.



73's de Edd

 

[pharaon]

FIRST see if the board works, when you remove the mentioned bad part, then worry about identifying a proper Zener, for later.

Yes it work fine

The series inserted 1K resistor / currrent limiter, is being a must.

Dos it have to be 1k or can it be greater

 

[73's de Edd]

Sir Pharaon . . . . .
Yes, it. can be larger.

73's de Edd

 

[pharaon]

Negative terminal to the ground plane and + terminal to the supply voltage side.

shouldn't the negative terminal with the strip be to the supply voltage side to now allow more than 18 v into the circuit

 

[73's de Edd]

Sir pharaon . . . . . . .

I think thaat we are on the same thought but just worded it differently with your use of "strip" instead of stripe.

In a diode the striped end is the identifier for the cathode with the unmarked end, left to be the anode.

As I mentioned, just have the striped end of the diode going to the power supply connection, and the anode going to the ground on the right side.
If the incoming voltage never exceeds 18 Volts nothing happens, it it meets or exceeds that voltage the diode starts conducting and bleeds down the voltage up to certain threshold where the Zener diode usually shorts out.



73's de Edd

 

[pharaon]

As I mentioned, just have the striped end of the diode going to the power supply connection, and the anode going to the ground on the right side.

you told me the opposite in your previous share

If you can't get the same part, you would have to go old school . . . .before these devices ever came on the scene . . . . .and use an 18V 1 watt Zener diode .
Negative terminal to the ground plane and + terminal to the supply voltage side

so i think i put it in wrong way like this..the stripe side to the right which is the cathode the the ground side and the anode side to the left which is the power supply side

should i reverse the position of it and make the stripe side to the left?

 

[davenn]

I seriously doubt that this is a diode of any sort in this position

SP will not refer to a diode .. it's supposed to be an overvoltage protection device ... spark gap etc

putting a zener diode in there will be pointless

 

[73's de Edd]

YES. . . .it is installed backwards.
Sir Dave must not have tuned in, back on page 1. Nor, being familiar on the parts supply in Cairo.