Burnt out reg? on WHR-HP-54G (buffalo)

[m_elias]

Let me know if this thread doesn't below here. I just so happened that the inverter I was using in my car has a 12V DC jack on it that fits into the WHR-HP-54G's 5V DC power plug. I plugged it in, left and returned 2.5 hrs later, started my car and saw some magic smoke!! I'm hoping only the reg (or diode?) needs replacing or bypassing, anyone know if this might be the case? I took pictures and tried attaching them. I have no problem warming up the solder gun to replace it but I'd like to know what exactly that chip does. The only labeling left on it is 'E33' and I think something starting with the letter 'B'. There is another on the back side of the board, same physical specs, it has 'E45' and 'BEH' on it.

Thanks

[999999999]

Re: Burnt out reg? on WHR-HP-54G (buffalo)

Since you haven't had any responses I'll venture a guess. It appears to be a linear, LDO regulator. I am "guessing" it is a 3.3V, opposed to 4.5V for the other one you saw on the back of the board. I'm not entirely basing that on the "33" in E33, also there has to be somewhere generating the 3.3V used by the memory chips on the back (at the least, I don't know what the other chips require but if you really wanted to know you could track down their respective datasheets).

Most likely it just overheated since it can't shed that much heat from a 12V input. I mean there is a fair chance nothing else is damaged that is directly related, but what 12V in might do to other not-so-related parts of the router, I don't know. I'd think it worth a try to repair it if you happen upon a chance to get ahold of an extra LDO regulator, even if it didn't fit the PCB and had to have a heatsink and epoxy elevating it off the board then air-wired to it, just so long as it has a modest 'sink (probably even a penny epoxied on would suffice as a 'sink if you keep it at 5V input from now on).

I think the "BEH" (or whatever your broken chip had instead) is just a lot #, inconsequential. I also say it's inconsequential because I used to have one of those routers and have a scanned picture of it. Unfortunately I can't make out anything at all of the markings on the corresponding chip to your failed one, but the E45 chip I can read and it's E45 BEY on mine instead of BEH.

I don't know how you made out with this repair but if this project is on hold and it would help, next time I visit the friend I sold this router to, I could pop it open and take a meter reading on the output voltage (which as mentioned above, I "guess" it to be 3.3V).

[m_elias]

Re: Burnt out reg? on WHR-HP-54G (buffalo)

Thanks for the info and suggestions. I have left this project alone for a while now. I should be receiving my new WHR-HP-54G shortly and compare with. Then I should be able to figure out what the chip was doing and possible replace it with an equivalent. Much appreciated!