Solved A little help with the RVL PMS

Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
So, I'm having a bit of trouble getting the voltage regulator to work.

I've already tested and trimmed the wii. But when I hook it up to the PMS with a battery and charger, there is no voltage coming from 1v, 3.3v, or 1.15v pads. I read that the RVL PMS doesn't turn on until a charger is plugged in, but I have a button and charger hooked up with about 5v reading on the charging pad. The battery is one of four Samsung 18650 3500mAh batteries which was giving off a stable 3.5v when soldered in. Ignore the one or two wires that are loose, they're ones I'm either not using or came out after I tested. I've triple checked that all the wires are on the correct pads and checked each one for continuity.

Could there be a short I'm not aware of on the board? I haven't taken the time to clean it yet. Or should I cut my losses and buy a new PMS?

IMG_7995.jpg
IMG_7996.jpg
IMG_7997.jpg
IMG_7998.jpg
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
It's also worth mentioning that there was some voltage coming from the board at one point. When I first plugged the charger in the led blinked dimly red and occasionally green but it stopped after I tried to rewire it with shorter cables. I didn't test then to see if any voltage was coming from the other pads.
 

Wesk

Undervolting....
Staff member
.
.
Joined
Jul 12, 2017
Messages
866
Likes
2,158
Location
Queensland, Australia
The issue looks like you're back-feeding the LDO. You've connected 1.8v from the PMS but you haven't removed the LDO.

If the LDO is still attached you'll need to remove the 1.8v wire.

[edit]

I just took another look over your pictures and noticed the 1.8v line isn't connected. Ignore my post.
 
Last edited:
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
The issue looks like you're back-feeding the LDO. You've connected 1.8v from the PMS but you haven't removed the LDO.

If the LDO is still attached you'll need to remove the 1.8v wire.

[edit]

I just took another look over your pictures and noticed the 1.8v line isn't connected. Ignore my post.
That's still pretty good to know. I don't know anything about the 1.8v so I wasn't sure if I even need one, I attached one just in case.
 

cheese

the tallest memer in town
Staff member
.
.
.
Joined
Mar 2, 2016
Messages
2,758
Likes
2,422
Location
Florida
Just to eliminate possible problems, I would start with removing the power wiring from the wii and testing for voltage from the PMS then. You may also want to remove all power from the board (disconnect charger and one of the battery leads) and then reconnect, battery first, then charger. That would make sure everything is reset if it went into some kind of weird state for some reason. If you get power when the wii is disconnected, there may be some shorting somewhere on the wii.

Either way, you may also want to clean all your boards with isopropyl alcohol and a toothbrush to make sure the flux or whatever else could be on the board isn't shorting anything (make sure to disconnect the battery first :P)
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Just to eliminate possible problems, I would start with removing the power wiring from the wii and testing for voltage from the PMS then. You may also want to remove all power from the board (disconnect charger and one of the battery leads) and then reconnect, battery first, then charger. That would make sure everything is reset if it went into some kind of weird state for some reason. If you get power when the wii is disconnected, there may be some shorting somewhere on the wii.

Either way, you may also want to clean all your boards with isopropyl alcohol and a toothbrush to make sure the flux or whatever else could be on the board isn't shorting anything (make sure to disconnect the battery first :P)
I think there might either be a problem with the PMS or USB-C. I went ahead and disconnected the power lines including ground but I'm still not getting any power from the board other than a 0.02v jump when I first touch the pad. I'm still getting voltage from the battery and charge lines but not even the fan or led seem to be getting power. I just cleaned off the board so I don't think there is any short coming from gunk on the board.

IMG_8003.jpg
 

Gman

RTFDS
Staff member
.
.
.
.
.
Joined
Feb 25, 2016
Messages
1,434
Likes
2,871
What do you measure on charge pad? What do you measure on VSYS?
 

Gman

RTFDS
Staff member
.
.
.
.
.
Joined
Feb 25, 2016
Messages
1,434
Likes
2,871
The charging pad is about 5v and the VSYS, if I'm measuring the right wire, is around 3.6v.
Ok that's normal. Good. Sorry if this is dumb but you have to hold the power button for 1-2 seconds to turn on the voltages, this is what you are doing?
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Ok that's normal. Good. Sorry if this is dumb but you have to hold the power button for 1-2 seconds to turn on the voltages, this is what you are doing?
Yea it is but I think I may have just created a new problem while testing the voltage.

IMG_8004.jpg


This is a bit of a bruh moment
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Ok that's normal. Good. Sorry if this is dumb but you have to hold the power button for 1-2 seconds to turn on the voltages, this is what you are doing?
It's also a bit hard to see but the problem may have been the button pad. It looks like the pad came a bit loose and if the board itself was fine it may have been that the button just wasn't working.
 

Gman

RTFDS
Staff member
.
.
.
.
.
Joined
Feb 25, 2016
Messages
1,434
Likes
2,871
Oh man that sucks. That chip is fried, you'll have to swap the whole chip with a new one now. Accidentally short something?
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Oh man that sucks. That chip is fried, you'll have to swap the whole chip with a new one now. Accidentally short something?
Yea probing parts I shouldn't have. I think I accidentally crossed one of the three capacitors to the left of the VSYS and overloaded whatever was in that chip.

Is that something I can replace or should I wait to buy another PMS?
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Oh man that sucks. That chip is fried, you'll have to swap the whole chip with a new one now. Accidentally short something?
I just looked over my old pics and I just realized there is a giant bead of solder that was on one of the capacitors near the fried chip that may have been causing problems.
 

StonedEdge

a.k.a. ClonedEdge
.
.
Joined
Nov 16, 2018
Messages
362
Likes
1,482
Location
Japan, Tokyo
Portables
2
As Gman said the bead isn’t really causing the issues as those caps are all filtering the voltage on VSYS, that wouldn’t cause a short. It’s quite easy to replace the chip with some solder paste and a hot air station. I’d recommend the SMD291AX50T3 paste from Chipquik.

Don't give up! I’d also recommend highly investing in some flux to use to make your solder joints nicer. The B+ joint looks a little cold and has exposed wires. You should make sure you tin your wire first so all of the threads are blobbed with a big ball of solder. It’ll make soldering to the PCB much easier.
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
As Gman said the bead isn’t really causing the issues as those caps are all filtering the voltage on VSYS, that wouldn’t cause a short. It’s quite easy to replace the chip with some solder paste and a hot air station. I’d recommend the SMD291AX50T3 paste from Chipquik.

Don't give up! I’d also recommend highly investing in some flux to use to make your solder joints nicer. The B+ joint looks a little cold and has exposed wires. You should make sure you tin your wire first so all of the threads are blobbed with a big ball of solder. It’ll make soldering to the PCB much easier.
Thanks for the encouragement! I really do want to get this to work so I placed an order for the new chip and a hot air station. If the station can install the new chip as well as remove it then I'm in good shape. I already have a flux pen that for some reason I forgot to use on some of the pads.
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Ok so I think I managed to solder on the new U7. The hot air station I got came with a better soldering iron than I had before so I went back and redid all the old connections with flux. The VSYS is measuring 2.6v which is good, but how do I know if the U7 actually works?

BB03900B-C530-4ADE-8693-0F2B1E42B84C.jpeg
 
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
Now that I think about it I don't know if the 2.6v is good. I tried shifting around the U7 to see if I could get a better connection but the best I got was 2.75v. Should the VSYS always be around 3.6v for it to work?

Small update: I disconnected everything from the USB-C board except for the button and GRD to see if that would work, it didn't but there is 1.2v on the button wire. I also tried wiring up a separate button I had laying around with the same result. I'm guessing there has to be a short on the PMS.
 
Last edited:
Joined
Jan 18, 2020
Messages
41
Likes
47
Location
Burbank, CA
Portables
1 Woodii
I hate to necro a thread but I managed to fix the problem so I'm dumping what I learned here. The 2.6v on VSYS wasn't normal and it was because I soldered the U7 chip on without solder paste like a doof. The VSYS is now 3.5v. After I fixed that the real culprit of my problem was a messed up button pad. I think the heat from soldering and desoldering the board too many times made the pad come loose so I had to scratch the trace and solder onto there.

buttonpad.jpg


I'm taking no chances on the wire coming loose so I glued it down, you can just barely make out where the blue wire is touching. Yes, I know the A pad has glue on it and I should probably remove the glue where the screw is supposed to go through.

Anyways, thank you everyone for helping me fix this!
 
Top