Believe it or not, I'm looking for parts...

S

starhawk

[H]F Junkie
Joined
Oct 4, 2004
Messages
8,908
...for an MP3 player. I'm treating this as an exercise in learning.

Player is a Samsung "Yepp" YP-T7Z/XAA. Needs a replacement LiPoly battery and a new screen.

I've got a source for the battery -- according to SamsungParts, the original was a 370mAH, 3.7v fella, which has long since suffered the Bulge of Death. I can get a replacement (400mAH) from SparkFun for right cheap. Yes, I know it's a larger capacity that probably will not fully charge in the player; I don't care because I know it will work adequately. I'm NOT paying Samsung 28 bucks when I can pay Sparkfun $8 (that's 2/7 the price lol) and get something comparable.

The screen, however, is playing hard to catch. It has a label on it that reads:
DC11-0084A V.2
VG-09N01-A
Click to expand...

I'm guessing that the first line is the actual model #, but I can't find either number on gooooooooogle. It may be proprietary to this model of player (but I doubt that).

I can say that it's a 1-3/8" diagonal LCD, square aspect ratio, and its lwh measurements are 1-1/4" x 1-1/8" x 3/32" overall. Not sure what the backlight is, but it runs off two wires that come off the main board of the player. Probably LED. Viewable area of the LCD is roughly 13/16" square. It's a graphic LCD, not a character LCD. Backing of the LCD module is reflective, like mylar or something. I'd post pix if my pix-taking skills were good enough.

If anyone's got tips on LCD sourcing for something this small, that would be AWESOME. Even an idea of places to bug would be great (already looked on eBay and emailed one seller).

Thanks folks!
 
There was something on hackaday a couple days ago about this kind of small LCD. link. Not sure if that'll help.

What's wrong with the LCD on the unit you have?
 
Are you trying to repair yours or do some sort of modification?
If you are trying to repair one I must say that I can't understand why. Assuming that I found the right model on google, you have a really old mp3 player that could be replaced with a modern one for what you are going to spend on parts.
 
Repair. The battery went all IMMA ASPLODE NAO and the LCD is cracked in about five different directions (probably the two are related...).

Yes, I know it's an old player, and I could get something newer cheaper. That's why I'm treating this as a "learning exercise". (The learning comes in trying to do SMT soldering to a flexible PCB, for the LCD backlight -- two places, don't short them please!)

It looks like I'm a better pix-taker than I thought. I'll post two photos in a minute.
 
Here's pix. The reflective backing shows up as black for some reason...



Looks like the primary IC (an ARM SoC of all things) has an integrated LCD controller -- there doesn't seem to be a discrete controller IC on there. Looking at the datasheet for the SoC now...

EDIT: SoC allows for a 16b parallel LCD, either STN or TFT. Unfortunately, I'm without a datasheet for the LCD, so there's no telling exactly how the signalling works, or where I could find a compatible replacement.
 
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I do this kind of stuff for fun, actually, and I think you're nuts for doing this as a learning experience. :p

If I were in your shoes, I'd start with the datasheet for the ARM and a multimeter. Find continuity between pins on the chip and the pins on the LCD connector. That will get you a pinout for the connector. Hopefully the controller on the chip has pins dedicated for certain functions beyond the 16-bit data bus. If they're not dedicated pins (i.e. the datasheet doesn't say something like "pin 23 is the clock output for the LCD"), then you'll have to break out a logic analyzer or oscilloscope. Find some datasheets on the intarweb detailing how various different LCD interfaces work, and compare what you have with the different interfaces until you find one that matches.

My guess is that most LCD panels are of a very similar design--this is commodity stuff here. Once you've figured out the interface, you'll need to find a compatible (from an electrical standpoint) LCD panel. From there, you'll likely need to create some sort of adapter to plug the replacement LCD's ribbon into the connector on the PCB.
 
The chip is a BGA package; pins are inaccessible. I'd quite honestly rather not risk frying the LCD further in the process of determining pinout... particularly since my multimeter (an analog RadioCrap special) doesn't have probes small enough for that connector (we're talking 0.5mm pitch here), and the circuitry goes under the Flash ROM. I don't fancy desoldering SMT ICs just to determine signal pathways.

...and the truth is: I am doing this mostly for fun. The "learning experience" part is just for parental-unit approval ;)
 
Is that large Samsung chip the flash storage for the player?

Well, without being able to probe the pins on the SoC, the next best guess is to take a close look at that LCD ribbon cable. Figure out if eight of the traces are similar (my guess is that none of them will have the extra components). It looks like there are only about 15 traces there, so that makes things a bunch easier. That means you've got a larger pitch and fewer contacts to figure out.

Try cracking open the LCD module itself, and see if there are any markings inside.
 
Managed to rip the part that goes to the backlight inside (the only part that was still connecting the LCD to the board, as those two traces are soldered down). Crap.

Got the mylar backing off (and it is mylar) to reveal an SMT LED backlight and a diffuser with some tiny tiny tiny numbers on it that I probably couldn't read without the use of a microscope.

The flexible board is marked as having a connector of 15 wires (1 thru 15) on the underside. Unfortunately, the circuit board was filled with epoxy and some sort of silver-colored bar by the kind and thoughtful folks who made this. May they rot in Hell.

BTW, Mohonri, if we knew that this LCD was a parallel-bus LCD, would that mean that ANY parallel-bus LCD with a 15wire connector would fit this thing and work just fine? or is the protocol specific to model/manufacturer/etc?

EDIT: any SIMILAR parallel-bus LCD -- TFT, not character or mono graphic. Yes, this thing does many many colors. It's like the screen in a nice smartphone, only dinky.
 
That LCD was busted anyway, so no loss.

I don't know for sure, but I'd be willing to bet that most tiny LCDs are going to have similar interfaces. You'll have to do some more research to figure out which lines do what, and then figure out which of the traces going from the PCB to the LCD are which line. I'm betting two of them are for the LED, eight for data (the ones on the bottom of the photo, I guess), one GND, one Vcc, and three for clock and a couple other control signals. You might ask the guy in the link above if you can get some of the datasheets he referenced. Then you're going to need to bust out an oscilloscope to figure out which lines are which.
 
There's a company in Raleigh NC (about an hour by car from me) called LXD Research & Display, that I'm gonna call tomorrow and ask some questions -- they make this stuff, and should be able to help.

My guess at this point (educated guess, but nothing more) is that I can get one of those stupid digital photo keychains from Wal*Mart and plug the LCD in here and have it work.

LED is broken out to a separate connector. As for the oscilloscope, I don't have one! (Isn't that what cavepeople used to debug fire anyways?) All I've got is a RadioShark analog multimeter.
 
More info. Looks like the connector is 7.5mm long by 5mm deep. Pins are 2.5mm high and like 0.4mm wide -- slightly smaller than the 0.5mm lead in my mechanical pencil (What? I'm an artist, too.). A count of the pins verifies the information on the board -- 15 wires. Pin 15 (as labeled) is GND. I *think* that Pin 14 MAY be VCC, but I'm a victim of poor labeling.

I used a lighted magnifier to read the insanely tiny text on the backlight diffuser, it's a long series of alphanumeric characters ending in "13100", which may be part of the model #, as that appears on the LED part of the flexible board connector as well. I'm gonna try and get the rest of the LCD housing out of the way, see if I can get more info from this thing. Note that gooooooooooogle did not find any results for the info on the diffuser.

EDIT: came apart more easily than I woulda thought. I'm going to need to get rid of that epoxy though if I'm gonna get anything more useful outta this thing. I'll google around a bit, but if anyone can give me pointers that would be awesome.

EDIT2: not epoxy, just cheap rubbery sh!t. Dunno what exactly the material is, but it scraped off nicely ;) That silver rectangle is actually some sorta really weird chip, but it's got spider-cracks all over it, so don't expect me to get anything useful off (I tried). Looks like the LCD is indeed a 13100 which may or may not be a Nokia job -- first link on gooooooooooooogle is to a pinout site's search function for a "nokia 13100 lcd".
 
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Hackaday dude found it, post here --> http://www.waitingforfriday.com/forum/viewtopic.php?f=10&t=1450

It's a VodaTech (some Korean company I've never heard of) VG-09N01-A. Of course it's not listed on their website. Of course they don't have an email address (and there is NO WAY I'm paying international phone rates for THIS).

So I have a call into a local company who may be able to help, and if they can't, gooooooooooogle will find me someone who can.
 
Chances are the Korean company wouldn't have anyone who speaks sufficiently fluent English for it to be any help, anyway.

So what are your next steps?
 
In my last post ;)

I've a call into a local company out of Raleigh NC (I'm like an hour from them by car). If they can't help me, I'll use goooooooooooogle to find someone who can.
 
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