CurtPalme.com Home Theater Forum

[CZ Eddie]

The board just kind of de-laminated itself.
I can just solder a wire from the one resistor to the other, to fix it?
Any particular suggestions for this fix?

[Nashou66]

As long as the trace is still connected from point to point(continuity) it should work. What you can do is get some clear nail polish and cover the trace to hold it back down.

Athanasios

[dvh99]

1 word of advice, get a proper soldering station and use flux so it flows nicely thru the board to the components surface.
i just repaired and modded a fgm in about 6-7 hrs.
35 parts in total including 3 opamps 14pins.
all with the aoyue it is simply a great help.
a simple wire will suffice i guess 2mm diameter or something.

[cmjohnson]

Your resistors are too large. If you're ordering 1/4 watt parts, get 1/8 watt instead. The smaller leads fit better in the holes in the board, which are sized for 1/8 watt lead sizes.

Trace repair is easy enough. But glue the trace down AFTER soldering, particularly if you choose to use superglue to put the trace back down. You won't like the smell of burning superglue, believe me.


Your soldering iron is inappropriate for the job. It's too large or too cheap. Get some paste flux, too. Those connections should be neat
and shiny, not looking like balls of crumpled foil. I'm also seeing whitish spots on the board that could be delaminations caused by prying at the board while it's hot, or by using an iron with too high a wattage. Then again, that could be dust. I'm not really sure.

Be careful and try NOT to burn the plastic bodies of some components next time, too. You CAN really damage the components that way.


The lifted trace should be backed up by carefully scraping back the solder mask on the trace, down to bare copper, and with your BEST
workmanship, back up the trace with some stripped, tinned copper wire along the trace path, and wrapped around the component leg. Solder this together...with great care and a good soldering iron with a fine tip.


CJ

[dvh99]

i used 1/4 watt metal film and they fitted nicely.
if you plan to do a lot of modding id get the aoyue 2702 its such a great device with a desoldering gun a hot air stick and a lot of tips and nozzles and some spare parts.
using that pikhouweel will do more damage then good.

[CZ Eddie]

I used wire to connect the messed up traces. Couldn't find any nail stuff.

Everything is working fine except for one thing.

Red convergence at the top wont offer full adjustment. Everywhere else is fine. Anyone know if there is a diagram somewhere of which components are used for the red on the convergence board? So I can narrow down my troubleshooting?

EDIT: Nevermind, the board layout itself shows you which components are for which colors.

Thanks for all the suggestions, btw. I modded every board in my 9500 several years ago succesfully. I've never had any board delaminate on me before.

[Nashou66]

CJ, the whole reason for going to a larger resistor physically is to stop convergence drift. Physically larger resistors deal with the heat better.


Athanasios

[CIR Engineering]

[tse]

All those little 1/8W size resistors are really 1/2W. The 5% ones with the blue body. Search for complete spec sheet at www.digikey.com.

Scott

[Nashou66]

Well, I did the test Mike Parker mentioned in his Maintenance thread and I reiterated it in mine, he called them "Mickey Mouse resistors". If you take a can of compressed air and hit those resistors with it on a stock CVA you can see a massive shift in convergence. After you put the larger sized resistors in with the same blast of cold air convergence will still move but not nearly as much as with the stock resistors, a much mmore stable convergence is the result.

I understand the safety reasons but they are still 1/2 watt but just larger in size. In the Safety spec'd locations we only use fusible types of the same wattage.

Also the larger ones I used have a better temperature coefficient , i think 30ppm .

Athanasios

[CIR Engineering]

[Nashou66]

Originally designed by Canadians is probably why

Athanasios

[Curt Palme]

[Curt Palme]

[Curt Palme]

[Curt Palme]

[Nashou66]

I questioned it too till I tried it. And i'll be damned it Happens just like Mike said in his original marquee thread.


PS: I couldn't resit the canadian dig

Nashou

[draganm]

not trying to be a jerk but the solder pads look pretty bad overall. Like the plating arounf the hole was chewed up before the new part was even soldered in.
how are you cleaning out the old solder before installing new parts. It looks like you might be a using a drill-bit?

[dvh99]

simplest way to desolder.
1 clean the entire board with alcohol let dry for 10 mins.
2 put flux on the pads that hold the components to desolder.
3 apply a little bit of fresh solder to the pads.
4 heat the pad and pull out the component gently to 1 side and then the other side.
5 use a simple vacuum pump (with a spring) and clean out the holes.
when done clean the entire board again with alcohol and wait 10 mins.
put the components in apply flux and solder.
1st put solder between the tip of the soldering pin and the wire of the component and once it flow apply the solder to the wire opposite of the soldering pin and hold a few seconds to let the solder flow through.
succes guaranteed.
and of course clean the entire board again.

[CZ Eddie]

Damn, you guys are killing me. It's just two pictures and you've got my soldering skills already figured out!?
Okay well you're at least half right about my skills.
I couldn't find my solder sucker and attempted to pull caps out of existing solder by heating the solder. Done it this way in the past succesfully, even though I know it's not a good idea. This is the first time I've had a problem with it though. Could be my new iron or it could be a cheap circuit board or it could be me just leaving the heat on for too long.

I'll go buy another freakin solder sucker already! sheesh!

Dragan, no I didn't use a drill bit. That's just old solder that hadn't been cleaned up yet.

[JustGreg]

Thas OK Eddie...I have been soldering for years and although I always took heat into consideration first and how purdy it looked second, I did alot of reading about soldering before tackling my Marquee boards.
The concensus is a good solder joint should be a dome shape when done with the lead coming out the top of the dome. I practiced for hours and hours on old crap and was happy with my methods...until I read this post. I didn't know we still had to use flux with modern solders but apparently I shouldn't have assumed so and bought flux core.

Should we (I) be buying solder without a flux core seeing as we're adding a paste flux?, and is it OK to use silver solder?

[stefuel]

I have two rolls of solder on my bench and use a couple of different size tips for the iron along with a gun for heavy jobs.
Both rolls are "flux core" and the only difference is size. I can't remember the numbers but the larger one is about the size of thick spagetti and the smaller about the size of angel hair pasta.

You really need good control over a small area like when changing STK chips with many pins in close proximity to each other. A small tip with thin flux core solder gives you that.

I haven't used seporate flux since I was in grade school which was before many of you were born