I got this one for free from a friend a long time ago.Looks from inside like it had been used in a
bucket of water a wet environment.
I just needed a router urgently and was a bit too lazy to run out to get a new one, so I decided to fix this one.
The symptoms are quite interesting: works, but lots of lag, instable signal, after some time of usage the speed drops to 10kbytes/sec over wireless. Wired works more or less fine.
While the soldering iron was heating up, I took apart this thing and powered it on . A GS1117 linear regulator heated up till it was too hot to touch, the shield above the RF part was corroded, a 47uF capacitor got 100% dead.
The first thing I’ve done – I secured the shielding with a bit of copper:
And, finally the regulator.
It gets a 3.3v input, and should give 1.8 volts out… But that measures like 1.56
Either something it powers got too hungry with age… or the regulator died. GS1117 and 1.8 volts. Something I don’t have around. Luckily, I had AMS1117 I just got from china. Same thing – different vendor. Even the pinouts are the same and package. But I only had 3.3 volts, 5 volts and adjustables. To adjust those you have to put 2 resistors: One between the ADJ and GND, one between ADJ and out.
The math is the same as for LM317, so I used 220 Ohm & 120 Ohm,I had around in SMD 0603 package.
Now I had to turn on my soldering ninja skills. I bent the ADJ pin to hook a resistor there, воткнул резюк:
Then soldered both of them.
I got steady 1.9 volts output, that theoretically should not exceed absolute maximum ratings, should it?
Anyway, that worked. Web interface rendered a lot faster, no more lags or loss of pings or speed drops. Signal could be better, and something tells me I should have replaced the rest of the caps, but I only had one around.
I also soldered in the pins for JTAG and UART. I wonder if I find the time to play with this one some time later. Enough necromancy for today.