Question: Is my router repairable?

[UNIT1]

Hello All,
Looking for some insight into the possibility of repairing a Wifi Router.

I have a need to use my router on location, away from house power.
It's power in is rated at 12V 2A DC.

I have used it 3 or 4 times (20 min each time) powering it directly from a UPS battery that is stated as 12V but when fully charged is actually 13.9.

Now, the router won't boot up or turn on. I'm guessing it was due to the 13.9V.

Any thoughts as to where to look for a failed component?

In the future I'm considering a DC Buck / Boost converter to keep a constant 12V
Thanks,
Unit1

 

[Martaine2005]

I’d be very surprised if 1.9 volt over voltage has damaged the router.
Was the router ever connected to the UPS while it was being charged?

Was the routers polarity reversed, even for a split second?.

I would first check for onboard fuse and/or input protection devices. ie diode, fusible resistor etc.

But a close look inside may show something obvious.

Martin

 

[UNIT1]

I'm sorry... let me be a little more clear.

I have a UPS with 12V 7AH battery. I pulled the battery out of the UPS and just took that with me on location. Then connected the battery directly to the router. I didn't think that 1.9V over 12 would damage it either but... its kind of looking like that.

I did open the router and looked around for a fuse. Didn't see a standard fuse, but an SMD fuse I might have missed.

Besides, and I'm just asking for clarification, doesn't a fuse protect for over-current situations? A 12 2a fuse wouldn't blow from the 13.9V would it?

Thanks,

 

[Bluejets]

Unusual these days for anything to be repaired unless the fault is obvious.
Just about everything is made as throw away.
If you have zero understanding of the unit then not much hope at all.
The unit would have tolerated slight over voltage so that idea is kaput.
Fuse will blow on fault, however you must then find what caused it.
Some have a fuse that doesn't appear to be a fuse to the uninitiated.
Board markings can assist sometimes.

 

[davenn]

I did open the router and looked around for a fuse. Didn't see a standard fuse, but an SMD fuse I might have missed.

Photos would help us help yo

Besides, and I'm just asking for clarification, doesn't a fuse protect for over-current situations?

yes

A 12 2a fuse wouldn't blow from the 13.9V would it?

but a little understanding for you ,,,, as the voltage increases across a device, so will the current ... basic Ohm's Law
so maybe the current exceeded the fuse value or some other component(s)

 

[UNIT1]

The router is an Asus Lyra Trio.

Good call Davenn, here's some pics

 

[UNIT1]

After borrowing an identical router and comparing the two... I think I found at least one failed component.

Here is a side by side comparison. See pic. Part labeled VR2 sure looks cooked to me.

This brings up a question that I'm hoping one of you can help me with.
1) Doing a google search for "39Q" reveals that this is a linear voltage regulator.
Q1: How can I find out the part no to order a replacement

2) Since it's labeled "VR2" on the board, I would think there must be a "VR1"
Q2: If anyone spots VR1, please let me know.

Thanks,
Unit1

 

[Alec_t]

Post #7 has parts missing?

 

[73's de Edd]

Sir Unit1 . . . . .

I see 1 major power supply and two minor power supply sections.. . . . being u/P port fed.

Here is the Da-DA sheet for yer most honnable reg-u-rator
https://alltransistors.com/smd-search.php?search=39Q

HOW 'BOUT THOSE . . . . .R584-R579 and C811-C810 pairs . . . . .don't ya just LOVE 'em ! ! !

Fuses . . . .FUSES . . . .? (see below)
Do a resistance check on discolored / faded / heated R419 and R515 . . . .000'ers.

73's de Edd

.

 

[Alec_t]

If anyone spots VR1, please let me know

The IC at top left of image '358 in post #6?

 

[kellys_eye]

I'd try to find the output voltage of that regulator and feed the corresponding DC in AFTER it to determine if the fault went further than the regulator itself as you could be wasting time, money and effort trying to fix the regulator part only to find the rest of it has gone mammaries skywards.

Fuses take milliseconds to blow whilst electronics take microseconds.

 

[73's de Edd]

Unit1 . . . . . . .Where you g. . .o . .o . .o . .o . .o . .o . .o .. o .. o ? ? ? ? ?

The IC at top left of image '358 in post #6?
Its telling you, at its 4:00 clock position, that its being U24.

Unit1 . . . .Can you set an ohmmeter up in its ohms function, and lowest range. Then place - meter probe to any of the metal sheet shielding for the RF circuitry at top and then use the other meter probe to read to each of the center pins of that 1F D 1F chip and see if both of them are being grounded also.
That would be 0 ohms or your meter lead loop resistance . . . .if you are using a better / pwemium bwewed meter.

Also you have a square of black cellular foam covering up about all of the surround markings of one yellow I.C. ? plus . . . it looks like its bottom center pin is showing blue green copper contamination.