Help identifying DS Lite trimmer potentiometers.

[akolemba]

This may seem off topic of the sites purpose… Or at least I assume anything non-cap related is off topic… But I need some help replacing a broken trimmer potentiometer.

You see, I broke off one of the two trimpots used on my Nintendo DS Lite when I was doing a case swap… I thought they were screws. >< Needless to say they control the screen flicker/dimmer. The one I broke off is VR2, and controls the upper screen.

Now below I've attached a little snapshot of a working board, this is what it should look like, my one is obviously missing VR2.

I don't have my calipers handy to get some measurements, nor do I even know how to begin measuring these with a meter. So I'm wondering if someone could provide some help.

Some of you may be wondering why I can't just solder the old one back on… It's gone. I was working on this project at my parents house and my mother decided to wipe clean the bench in the garage. With the cleaning went the tiny trimpot. Go ahead, get your laughs in, I got a good chuckle too.

But, these are tiny. Like 1mmx2mm if I was to eyeball… and I'm very bad at eyeballing. Like pinheads. As soon as I get my calipers back I'll post better measurements.

From what I can tell they are full revolution ones. I'm assuming it's a single revolution before reset, there doesn't seem to be any resistance to multiple single direction revolutions, but I haven't really tried to push this theory. Come to think of it they almost certainly are single full revolution trimpots. With the board powered up, the lower screen will adjust to a point before resetting, from what I remember.

I'm also assuming that they are probably ceramic.

For those wondering, these are to the right of the cartridge hoppers if looking at the back of the lower screen board. The pot between VR1 and VR2 is the volume slider.

From what I caught somewhere I was told to test between 1 and 3, of the 3 points on the trimpot. But again, I'm uncertain what points to test or what to have my meter even set on to get some data.

So I guess the final question is what kind of trimpot do i need? Thank you again everyone for your time. I appreciate any and all help. Take care!

[Radio Fox]

Looks like a 3mm cermet trimmer. Unless you can persuade someone else to take their DS apart & remove the trimmer, or get hold of a circuit diagram, then there's no way of knowing what value it was.

You could assume that it is the same value as the other trimmer. In which case it would have to be removed first, to measure it's value. Measuring it while still in-circuit could give a false reading, depending on the configuration of other components in that part of the circuit.

You would need to measure the resistance across the leads which were connected to points 1 & 3 with an Ohm meter to give you the value you need.

You don't say which part of the world you are in, but if USA, then Digikey have a large selection to choose from. I've only had a quick browse myself, but it looks like the Murata range might fit (2.75mm X 2.2mm). The important part is the lead spacing, as it looks like you have enough space for a slightly bigger body if need be.

http://search.digikey.com/scripts/Dk....dll?Selection

[kikkoman]

i've got a disassembled DSlite somewhere. give me a day to find it and measure that thing.

[Krankshaft]

Also take some pics of the missing POT location on the board chances are you ripped some traces off with the POT too.

Hopefully the traces damaged are on the same layer as the POT was so they can be repaired.

[Radio Fox]

Hey! What happened to my link? It should have shown miniature trimmer pots, but it's linked to surface mount caps!

Let's try again:-

http://search.digikey.com/scripts/Dk....dll?Selection

Just in case it hasn't worked again, go to "product index" from digikey's home page, click on "Trimmers" under the "potentiometers, variable resistors" heading. Select "single turn, top adjustment, surface mount, cermet". Apply the filter & view the pages.

EDIT...it's done the same thing again...strange!

[kikkoman]

alright, i've checked on mine.
i suspect it's a 39k pot. i haven't unsoldered or disconnected it otherwise, but the total value i measured (38.68k) is close enough to a E12 value (the 39k).
value between 1 and 2: 15.23k
value between 2 and 3: 23.45k.

you could simply try 2 resistors (15k and 24k) and see if it works.

those traces look okay.

[mockingbird]

What would happen if you just shorted the 3 solder points together with solder?

[kikkoman]

probably nothing, but seriously, i don't want to try.

[stj]

if you join all 3 and they are all used you may blow the power section.
it may have +v on one pin, -v on another pin and the 3rd pin going to the bias line on the controller.

[Radio Fox]

Originally Posted by kikkoman

alright, i've checked on mine.
i suspect it's a 39k pot. i haven't unsoldered or disconnected it otherwise, but the total value i measured (38.68k) is close enough to a E12 value (the 39k).
value between 1 and 2: 15.23k
value between 2 and 3: 23.45k.

you could simply try 2 resistors (15k and 24k) and see if it works.

those traces look okay.

Trimmer pots don't always follow the E12 values. There are no 39k trimmers on the digikey site. It's more likely a 50k pot, or above. You are probably reading a resistance on the board in parallel with the value of the trimmer.

Out of interest, did you measure both trimmers, or just the one in the VR2 position?

[kikkoman]

of course you're right about the E12 values. where's my head?
i cut 2 of the 3 traces and came up with a total value of 45.6k (and 17.2k and 28.4k respectively).

the next available value would be 47k:

http://search.digikey.com/scripts/Dk...=490-3931-1-ND
which isn't in stock atm.

that leaves us with this one:
http://search.digikey.com/scripts/Dk...=490-2043-6-ND
which should be the exact part by the looks of it.
murata makes them in 47k too but digikey doesn't stock them.
according to the mfr they're 30%tolerance (not 5% as digikey says) so it's hard to tell which is the one. but that's nitpicking here.

Out of interest, did you measure both trimmers, or just the one in the VR2 position?

the other one gave similar readings. i didn't mess around with its traces though.

[Radio Fox]

With such a wide tolerance a 50k trimmer would probably be OK.

Digikey sell a Panasonic one in a similar package size to the Murata (2.8mm X 2.2mm).

http://search.digikey.com/scripts/Dk...me=P2N503CT-ND

[stj]

you can salvage those trimmers from the side of most laser assembly's
look for a busted dvd player.

[mrsetiman]

Hello, I was wondering if anyone had success with those digitkey pots for repairing the DS lite because I unfortunately had this exact same problem.

[befoote]

http://www.logictoyz.com/nintendo-ds...set-2pcs-.html

[b700029]

...so the place selling them doesn't even know their value?