wrt54 v1, too much voltage

I've got a linksys wrt54g v1.0 that I've burned by using the wrong ac adapter. I accidentally used a 10v dc adapter. It ran for ~10 minutes before I heard multiple pops, and a smell of burning chips. Now, if I plug in the original adapter nothing happens, the leds don't come on. Cosmetically I don't see anything wrong with the board or components.

I've read the thread on the fried wrt54g because of ac. But I didn't see a solution. From that thread, it seems that the buck converter chip, and the diodes are probably the culprits. Is there anyway to test them? or are there other components that seem likely too?

Reply to
Loading thread data ...

Poof. The v1.0 mutation runs on 5V 2A adapter.

No solution. I can identify the components that are fried, which can be replaced if you like.

It's easier and cheaper to replace them. Duz your v1 look like the v1 in the photo?

If ues, then it's an RT9202 regulator with external FET's to increase the power output.

I'm not sure about the numbers on the FET's

Or does it look like this?

If yes, it's an AP1501-33:

Reply to
Jeff Liebermann

If the 10V adapter was a linear device (transformer inside) then its output voltage may have been 12-15V easily. Or more!

Good job doing a search first!!

Replace Find a used v2, v3, or v4 or a newer GL version. Or a Buffalo WHR-HP-G54 if you can find one.

Yes - the smps & the TL7705 supervisory chip is all I could find that ran directly from the +5V input.

Not easily. Repair is probably possible but not worth the hassles!!

TL7705 - it might have survived - see above.

It could have been worse I suppose - the v1.0 only had a 125MHz cpu. I think all other versions have at least a 200MHz.

Having said that, my v1.0 has been running dd-wrt nicely in an outdoor enclosure for 9 months now.


Reply to
Kim Clay

It's definitely a 1.0, with the minipci card. I found that the RT9202 isn't produced anymore, but I also found an identical replacement. I plan on ordering it, and the diodes from mouser.com. But the diodes are a bit of a problem. I have no idea what specification they are. All I know is that they are surface mounted. Do you guys know their specs? or do diodes even have specs? I've only worked with the typical generic ones from mechatronics labs, and I've never blown any of those.

Also, are the FETs possible culprits too? Are they sensitive to higher voltages?

With the prices I've seen on ebay, repair may be the cheapest for me. and I've got to break that new soldering iron in sometime. :) I've been running newer versions of the wrt54g but they don't seem as stable as the original.

Reply to

Where? I'm interested.

Look on the schematics on the data sheet:

Panasonic makes the MA732 diode on the schematic. Looks like a fast shottky diode.

Yes, diodes have specs. There are quite a few different types.

It's highly likely that both FET's are also blown. I had numbers off of those from the board, but I don't have V1 board handy.

Ok. However, I value my time. What I do is buy the parts, stick them to the unit, and wait until I have some of that mythical spare time to work on it. Then, I do perhaps a dozen repair jobs at once. Setup and cleanup time plus finding the parts is what kills me, not the parts cost.

Duz the new version have a version number? I'm running v24 RC6.2 on perhaps a dozen local wireless hot spots and business customers, with zero issues. I haven't tried RC7 yet.

Reply to
Jeff Liebermann

The FAN6520. From comparing the spec sheets I believe this is a replacement for the rt9202.

I'm ordering the FAN6520AMX from mouser, 512-FAN6520AMX.

I'll order a some of those too. But looking at the data sheet it has the forward voltage at around 0.3-1v. Maybe I'm reading the circuit wrong, but doesn't the wrt54g feed 5v through them?

for any of these. I'm not sure what the numbers mean. A quick google but didn't produce anything useful.

You sound like you are very very busy.

I mean the newer versions of the router. I've got a v5, and v6. They seem to need reboots more often than the v1. I'm not sure which version of the dd-wrt they are running, maybe a firmware update is in order. Those two were harder to get dd-wrt on, so once I had it running I didn't try updating.

Reply to

Looks like a good substitute. However, I didn't look at it very carefully and may have missed something.

I don't know. I haven't traced out the power circuit wiring and the reverse engineered schematics previously posted are un-readable. I don't think so, because in the data sheet schematic, the diode is in the feedback circuit and doesn't carry the full +5VDC load.

for any of these.

Those were the numbers on the FET's. I'll try again (later).

I've had mixed experiences with stablizing V5 and V6 routers. When they first appeared, they both would hang erratically, requiring a power cycle. I installed DD-WRT v23 on one or two V5 routers, which did nothing. About 3 months ago, I tried again with a friends V5 router using DD-WRT v24 SP6.x. That worked and the router has been stable ever since. However, he wanted more features, so we traded a V5 for my V4 router, which has more ram and runs a more feature infested version of DD-WRT. With such limited units and testing, I can't claim that V24 fixes the hangs, but it sure looks that way.

Reply to
Jeff Liebermann

Here I have duplicated a small schematic from my May 23, 2007 post: (use fixed pitch font) +------>7705 chip | Jack1(+)--L2---F1---+-----+-----+-----+-----|>|--->SMPS(RT9202) (-) | | | | 0.188V | +-----+ | | | | 1000uF| _|_ --- --- --- L1 16V --- /_\\ --- --- --- | 105° --- | | | | _|_ _|_ _|_ _|_ _|_ _|_ - - - - - - ID= DS1 CK1 CA3 C3 D1

Device Zss smt smt smt Zss ID 33 chip chip chip 33

Match the device name to the input ckt shown in this pic:

D1 had Vfwd of 0.188V when I measured my working unit in 2007. I don't remember if the measurement was taken using a VOM diode test or if it was taken under actual operating conditions.

Looking at the above pic DS1, D1, & D2 are all the same. At least DS1 should have survived. Maybe even D1 survived.

I am about 99.9% sure of my ascii schematic.

FETs quite likely are blown. I never found a data sheet for the FETs, or what they might cross to.

for any of these.

In the above pic you can see the RT9202 gate drive leads from pins 2 &

4 going through some low R (

kc - who just found a V2 with SpeedBooster for $8 :)

Reply to
Kim Clay

Well I ordered the parts, and I've managed to buy another wrt54g v1 for $20. So in a week its time to solder.

I just picked up a wrt54gs v4. Do you guys know the voltage range of this particular model? I opened it and looked, an half the chips around the plug are covered in super glue.

Reply to

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.