Lilliput auto-on mod (Coyote's mod) gone wrong!

JayKaye · 05-12-2004, 06:23 AM

Hi all,

I hope someone can help me. I did Coyote's auto-on mod ( http://www.mp3car.com/vbulletin/lcd-display/24047-my-solution-auto-power-lilliput-screen.html ) and it worked fine. But the solder joint where the 10k resister was replaced came off and it pulled the soldering contact off with it!!! I cant solder anything onto that point anymore.
Is there any way of finding another point to solder to? please say there is! im freaking out here!

To clarify. The point that came off isnt where the resister is connected to 5v nor is it ground. It is the point where the 10k resister was taken off.

Thanks in advance.

JayKaye · 05-12-2004, 07:40 AM

I was just thinking, if someone who has their lilliput already open and has a multi-meter handy could pls find an alternative soldering point to the one i ripped out accidentally. Just use your continuity on the multi-meter and find a point that has no resistance in it.
I would do this but my point is ripped out and i dont have a spare lilliput handy.

Thanks

JayKaye · 05-12-2004, 10:26 AM

Pleeease! anyone out there can help me???
My lilliput is completely gutted on my bed and i want to goto sleep soon! haha.

Seriously though, I would be soooo damn appreciative is someone could please take the time to find an alternative solder point to the one circled in green in the picture below.

Curiosity · 05-12-2004, 11:22 AM

Uh, the one with the trace running to the second pin down on the SyncMOS chip? That's what it looks like to me. The meter says it's connected there too. Just be carefull this time and glue that cap down so it doesn't move!

JayKaye · 05-12-2004, 11:31 AM

Thanks for your reply Curiosity

I thought that too, I tried soldering the cap/resister to the 2nd pin of the SyncMOS chip but that didnt seem to work. Are you 100% sure that it is that pin? From what I can see on the board the trace doesnt go directly to the bit thats been ripped off my board, instead it falls around 1 mm short of it and theres a tiny drill hole where it ends. I dont see any visible signs that they are connected though.

Curiosity · 05-12-2004, 11:42 AM

Yes, I'm sure it's a direct connection. You can't tell because of the white over it. Was the hole damaged? That could be connecting to something on the other side of the PCB.

JayKaye · 05-12-2004, 11:45 AM

The hole isnt damaged. I scratched off a little bit of the non-conductive covering to get a multi-meter point, but other than that its in good condition.
When you say you are sure, is this by visual inspection or using a multimeter?

Sorry for the 20 questions. But if that point definately goes to that SyncMOS chip then I must have a problem with my screen elsewhere. I need to be 100% sure before I look for a problem that may not even exist.

Curiosity · 05-12-2004, 11:49 AM

Yes. I checked it with a multimeter from the resistor to the chip. I don't have the mod, so that's the resistor you used to have.

JayKaye · 05-12-2004, 11:51 AM

great! thanks heaps for your help Curiosity.
Will post updates on my progress in this thread

JayKaye · 05-12-2004, 12:09 PM

ahhhh SUCCESS!

huge hugs 'n' kisses to Curiosity!

turns out that my capacitor/resistor combo had somehow killed itself. When I tried the 2nd pin from SyncMOS again it still didnt work. Luckily I had bought spare resistors and capacitors and I used 2 new ones and it works. Not too sure whether it was the capacitor that died or the resistor but i will hopefully find out when i tidy up my soldering a bit.

JayKaye · 05-12-2004, 12:14 PM

ok, another update.
I replaced the old capacitor to find that it still works. So the old resistor must've shot itself.
Anyone know how this could have happened? I have set my soldering iron at 240 degrees (celcius) but usually have it around 300 for normal soldering. Could it be that my iron was too hot?

I replaced the 150K resistor with a 68K and 82K and the screen is chugging along fine now

now I need to glue it down and pack it up...

/me crosses fingers

Curiosity · 05-12-2004, 12:14 PM

Great news! I bet you're feeling much better knowing it was the mod that killed itself and not something else.

JayKaye · 05-12-2004, 12:34 PM

hehe yeh, definately!

The lilliput is all back together again in the in-dash housing. Unfortunately the buttons on the screen arent working at all now! ARGH! im 100% sure i wired up the mod properly so im not going to pull the screen apart again.
Maybe it doesnt work because ive soldered the joint onto the leg of the SyncMOS chip? if anyone knows, please let me know how i can fix this. I really dont want to go through my lilliput not working again, i think i grew my first grey hair tonight :O

infinkc · 05-12-2004, 12:55 PM

the ribbon cable is extremely touchy, if i remember correctly the cable has to be twoards one side more inorder for the buttons to work, good luck.

Curiosity · 05-12-2004, 12:59 PM

It's probably just the ribbon cable. Make sure the end on the controls is slid towards the IR sensor before you lock it down. Odd, I never really have trouble with the other end.