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#211
Re: The VB Glitchy Display Problem
Posted on: 2013/10/28 11:55
Newbie
Joined 2013/10/11
Spain
8 Posts
Long Time User (6 Years)
Quote:

vb-fan wrote:
Not familiar with that screwdriver --- is it a tube with splines on the inside? If you caught my earlier comment, I took an old philip's screw-driver and filed it flat on the end (think I heated it and removed the temper first); then drilled it out so it fit snug on the screws, then tapped the end three times with a chisel (making six little tabs that grab the screws perfectly); then heated it in a blow-torch to cherry red and quenched it (re-tempered). Works fine, bet there's enough of your screw head left to work (unless your gamebit is already that shape).

The next move if all else fails, is to drill a hole into the head with a small drill-bit (hardest part will be getting the bit STARTED, centered would be nice), then use an "easy-out". The screw is after all, metal --- and it's stuck in plastic. The plastic's alot weaker than the screw...


Thanks for your comments. You're right, I'll try to get the philips flat and drill it out. I can barely see inside the deep hole, but I hope the screw head still keeps a couple of marks to grab onto.

Thanks again!
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#212
Re: The VB Glitchy Display Problem
Posted on: 2013/10/31 10:07
PVB Elite
Joined 2003/7/25
USA
1507 Posts
PVBCC 1stCoderContributor#3 PosterHOTY09 EntryLong Time User (15 Years) App CoderPVBCC 2010 EntryPVBCC 2013 Entry
I just came across something interesting... Z-axis Conductive Tape (like: https://www.sparkfun.com/products/12042 ). I think this (or something similar) might have been what they originally used at the factory for these cables. According to 3M, it's main purpose is for connecting flex circuits to other to other flex circuits or PCBs.

Here's an interesting quote from the datasheet:
Quote:

Mechanical Clamping
To assure electrical resistance stability of Tape 9703 in any flexible circuit interconnection application, a mechanical clamp or other compressive force (i.e. foam strip held in compression over bond area.) should be considered in the design of the application. Any stress inherent in the assembly design (i.e. tensile, shear, cleavage) or temperature excursions (encountered through normal product use) applied to the bond area could result in an electrical open in the bonded circuit over time when no clamp or mechanism for maintaining a constant compressive forces is used. A well designed mechanical clamp will reduce the environmental stress on the bond line and improve the electrical reliability of the bond. In addition, the temperature operating range for the adhesive can be improved with a properly designed mechanical clamping system to ensure the conducting particles in the Tape 9703 maintain electrical contact. Several types of
mechanical clamps have been used successfully including foam strips attached to lids or cases and screw-attached plastic clamps. Contact your 3M Technical Service Engineer for further information about mechanical clamping.


So, if that's what was used, and with no mechanical clamping... I guess even the manufacturer could have guessed that it'd fail.

Anyway, if anyone is looking for a solder-free method to fix displays... carefully peeling the cable from the display, cleaning the contacts, and carefully aligning/sticking the cable back down might be a possible solution. Of course a mechanical clamp would be a good idea, like: http://www.planetvb.com/modules/newbb ... t_id=25208#forumpost25208 . And actually, if anyone is looking to try this, I'd be glad to perfect that clamp design and mail you a set (you need to provide your own Z-axis tape though... I don't have any yet).

The datasheet specifies the minimum gap as 15 mil (0.4 mm), though below, it says "Minimum free space between adjacent conductors suggested to ensure electrical isolation. Customers may qualify finer pitch performance in their applications."... so it sounds like it should work smaller, but you need to verify that there are no shorts. I believe the gap is approximately 0.3mm on our cable.

On another note... I want to see someone use it as an alternative to soldering BGAs, like they did for the QFP in the Sparkfun video. ;) "Aww man... BGA rework is such a hassle" . ;)

DogP
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#213
Re: The VB Glitchy Display Problem
Posted on: 2013/11/1 2:14
VB Gamer
Joined 2010/10/19
France
37 Posts
10+ Game RatingsLong Time User (8 Years)
I'll give it a try, thanks DogP :] What could go wrong if it makes shortcuts everywhere after all ?
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#214
Re: The VB Glitchy Display Problem
Posted on: 2013/11/3 6:38
VUE(xpert)
Joined 2011/7/3
USA
435 Posts
CoderContributorLong Time User (8 Years) App Coder40+ Game Ratings
OK so I fired up my little red buddy and my right screen was way outa wack. so I talked it over w my very smart friend and he said it's probably the mirror sensor and I should buy some compressed air to fix it up. So I tried that screwed it all together and everything was Hunky Dorey until...I changed the IPD and then all heck broke loose. I instantly knew it wasn't the PCB connection my I got that fixed and the guy that did it did a bangin job I might add. So I had to diagnose it all by my lonesome. So I prayed about it and then I opened it again and noticed that my left PCB flexable circuit was creased, not beyond repair just enough so It was screwing with the display. so I carefully removed the PCB and got out a towel to Iron on and a good iron made sure that there was'nt any water in the iron. Got the old iron hot on the lowest setting not hot enough to melt the PCB flexable circuit just barely hot enough to be uncomfortable on your hand then I unpluged the iron and Ironed out the PCB flexable circuit. Put in Vertical Force and sure enough it was good as new.

DISCLAIMER

Now I'm not telling you to do this I'm just saying it worked for me. if you decide to do this on your own Be extremely careful w the heat setting of the iron if it's too hot it's GAME OVER NO SECOND CHANCES IT'S TOAST. Check the iron over and over again by touching it and making sure it's not too hot. I even unplugged the iron.
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#215
Re: The VB Glitchy Display Problem
Posted on: 2013/11/5 9:47
PVB Elite
Joined 2009/12/30
Netherlands
545 Posts
Highscore Top10Highscore Top ScoreContributor10+ Game RatingsLong Time User (9 Years)
Let me first tell you this, I am not saying the person who repaired your screen didn't do a bang up job, it can sometimes happen that a connection isn't completely through and through, it has happened twice to me.
With that out of the way, I think there is a problem with the soldering Morintary and the Iron trick just helped getting the trace on the display board for a while, just like the oven trick.

The problem you are describing with the IPD is something I have seen myself a few times when soldering displays. It means that one or more traces didn't get a good connection while soldering.
I just got one display back from a member here that had the same problem which I barely got right again, though I did. You can't see it with the naked eye, but it surely must have been a bad connection in your case as well. So be warned that it probably will come back.

If a crease in the cable would really have been the problem, it wouldn't have been repairable like you did as copper doesn't work that way.
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#216
Re: The VB Glitchy Display Problem
Posted on: 2013/11/5 21:27
VUE(xpert)
Joined 2013/8/23
USA
301 Posts
Long Time User (6 Years)
I finally managed to "level up" my soldering skill and fix one of my displays :). After applying NaOH per DogP's instructions, and putting it in the oven for a short time (along with some rosemary sprigs and a dash of salt), I was able to peel away the remaining plastic on the cable to get at the copper contacts.

It took me a while to get this whole project done, partially because of my lack of soldering experience, but also because I messed up when cleaning the bared contacts with a fiberglass pencil. Some copper from the flex cable was getting peeled up instead of just being polished clean on the first PCB I did. I also think perhaps not all of the plastic from the cable had dissolved. So on the second one, I very carefully used a pushpin thumbtack to peel up the remaining plastic. I held the pushpin over the PCB, with the needle end facing up towards the flex cable. Then, just gently worked the tip under the remaining plastic of the cable (between the copper contacts of course).

After a few times powering on the VB to test my work, the displays were somewhat working until I finally found an area with an obvious short circuit/sloppy solder job. Now, that display works almost like new!

One final question (sigh...)- how should I clean the oscillating mirror?? I know the right answer is "I shouldn't clean it". There seems to be a smudge or something on it, which at first seemed like tiny scratches on the red plastic lens my peripheral vision would pick up. But, I can see now it's actually on the mirror >:|. Not sure how it got there either, I was always careful not to touch it and always wore an N95 respirator mask when the VB unit was opened up so I didn't blow any dust in.

In case anyone was wondering, I bought a Kendal 937D soldering station on Amazon for like $50. Comes with 5 tips (two are tiny ones, perfect for this project), and has a very accurate temperature knob/display. Heats up VERY fast as well.

Enough rambling- thanks to DogP for the great post on how to carry out this project! Also thanks to TheForce81 and RunnerPack for their advice in the matter as well :)

Attach file:



jpg  PCB1b.jpg (907.57 KB)
3574_52795492b9952.jpg 2048X1536 px

jpg  PCB1mount.jpg (646.85 KB)
3574_527954a2f25ad.jpg 2048X1536 px
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#217
Re: The VB Glitchy Display Problem
Posted on: 2013/11/6 4:51
PVB Elite
Joined 2003/7/25
USA
1507 Posts
PVBCC 1stCoderContributor#3 PosterHOTY09 EntryLong Time User (15 Years) App CoderPVBCC 2010 EntryPVBCC 2013 Entry
Quote:

Craby wrote:
I'll give it a try, thanks DogP :] What could go wrong if it makes shortcuts everywhere after all ?

Heh, hopefully nothing... I've had several shorts over the years, and never seen any permanent problems (always cleared up as soon as I removed the short). Not to say that a bunch of them won't hurt it, but a simple test with a multimeter should let you verify before powering it up.

Quote:

HP Lovethrash wrote:
One final question (sigh...)- how should I clean the oscillating mirror?? I know the right answer is "I shouldn't clean it". There seems to be a smudge or something on it, which at first seemed like tiny scratches on the red plastic lens my peripheral vision would pick up. But, I can see now it's actually on the mirror >:|. Not sure how it got there either, I was always careful not to touch it and always wore an N95 respirator mask when the VB unit was opened up so I didn't blow any dust in.

Nice work... about the smudge, are you SURE it's on the mirror? I've noticed dark lines several times, where it seems like it'd be the mirror or the red lens... but it's actually dirt/dust on the clear cover over the LED bar. A simple wiping of the clear cover takes care of it.

DogP
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#218
Re: The VB Glitchy Display Problem
Posted on: 2013/11/6 13:46
VUE(xpert)
Joined 2011/7/3
USA
435 Posts
CoderContributorLong Time User (8 Years) App Coder40+ Game Ratings
DogP wrote Quote:

I've noticed dark lines several times, where it seems like it'd be the mirror or the red lens... but it's actually dirt/dust on the clear cover over the LED bar. A simple wiping of the clear cover takes care of it.


DogP are you referring to the lens in front of the LED? or something else?
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#219
Re: The VB Glitchy Display Problem
Posted on: 2013/11/6 22:37
PVB Elite
Joined 2003/7/25
USA
1507 Posts
PVBCC 1stCoderContributor#3 PosterHOTY09 EntryLong Time User (15 Years) App CoderPVBCC 2010 EntryPVBCC 2013 Entry
Yeah, the clear lens on the front of the display board.

DogP
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#220
Re: The VB Glitchy Display Problem
Posted on: 2013/11/7 5:04
VUE(xpert)
Joined 2013/8/23
USA
301 Posts
Long Time User (6 Years)
I had the foresight to give the clear covers a good wipe with a microfiber cloth before screwing them back in. I can see some kind of smudge or faint smear on the left mirror though. However, I got to wondering if that's not part of the issue- would a fleck of dust on the mirror create little black lines on the display? Once the mirror oscillates, the dust would appear more as a small line than a speck, or so my brain would think. Maybe I will try using an air can to blow out any stray particles.

The little lines I see are only noticeable over brighter red areas, the title screen for 3D Tetris is a good example. They aren't huge, straight lines like the original display problem...just little annoying ones that seem to move or shrink somewhat if I move my head to the side slightly while playing.

Still kind of curious why the mirror looks streaky at a certain angle, maybe it's a non-issue...

Quote:

DogP wrote:
Yeah, the clear lens on the front of the display board.

DogP
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