REPAIR GUIDE - TurboExpress/PC Engine GT: Video Fix

[Platinumfungi]

Nat - No prob

Duo_R - Ha! You know what I meant.

[agt_dale_cooper]

Confirmed working here...Radio Shit P/N 272-1024, 4.7uF, 35V, $1.19.  Can't find anything 35V submini at Parts Express (my new favorite store, thanks again, PCEH), but did find a 50V submini (020-1654) which I think is easier to stash in the CRAMPED space where this thing goes.  [Noting along the way that the white stuff is the vicinity of this cap is space-filling FOAM, and can easily be broken off to provide more real estate...]  Not sure I want to exceed the original voltage spec, though...will find a way to jam the 35V in (NICE pics, folks!), will test the quality of my soldering job by bending the bejesus out of the leads...now I get to do the audio fix on this thing, because the audio sucks.  Yay. [Thrilled smiley omitted]

[Duo_R]

I found a way to install the Vid cap pretty easily, even if it is a larger cap. I will post up pictures later, but u just keep the legs long, solder, and then bend the cap over to the other side of the PCB, and almost a 90 degree angle (perpendicular to the board on the other side) this fits nicely into a space in the system housing. It is a snap to install this way.

[agt_dale_cooper]

Correction:  Parts Express 50V submini is 020-1634.  Fits in space provided without having to bend the bejesus out of anything...hope the higher voltage doesn't screw anything up...

[Windsor75]

Hello

Because it's my first message, I'll introduce myself a little. I'm 33 and just came in the "Nec World" I didn't know. I bought two months ago a Duo-RX and some weeks ago a GT.

This GT needed one or two minutes of "warm up" before the screen displayed the game clearly. I read this topic, and thought about replacing the cap at the top of the mobo. But because I never did this kind of stuff, I didn't.

But sadly, yesterday evening, after I played a game, I turned it off and on with another game, but the screen never turned on. I only had the backlight.

So, I have two questions, before I try to repair it :
- I suppose that changing the cap could fix it, am I right ? Or is the screen dead ?
- Is it difficult to do for someone who never did it ?

Thanx for your answer

[Platinumfungi]

Hey Windsor, welcome aboard.

Having a backlight but no picture definitely sounds like the issue discussed in this topic.

As far as whether or not it's difficult really depends on your level of experience with electronics. If you have used a soldering iron before and have some familiarity with circuit boards then you should be good.

If not, then I'd suggest practicing on some broken circuit board or buy some project board from Radio Shack. You can look on Youtube or do a google search for "proper soldering" or "soldering techniques" or something like that to get some good instructions.

Use a 15 watt soldering iron to be safe (which you can get from Radio Shack for around $8 if you need one).

It's not hard once you get familiar with soldering, but I'd highly recommend having a little practice under your belt from a different pcb before you work on this one.

Good luck!

[Windsor75]

Hi Red Ghost,

Thank you for your advice. I think I'll train on an old VCR I have before fixing my GT !

[Platinumfungi]

Sounds like a great idea. Let us know if you need more help/direction.

[ColterF]

Nat/ Punchy Pedo,


     Did the backlight work before you fixed it, did you games have audio, I'm having a similar issue but not sure if its the same, my TE will turn out, the backlight goes on, but no sound, no picture.

[Duo_R]

I have done a good amount of TE's, and I have seen bad sound, bad video, and bad sound AND bad video cap Turbo Expresses. It is extremely rare to find one that truly has a bad screen. In this lot that I fixed, one of them had bad sound, and when it arrived at my door from the owner, it also had bad video cap. My advice is to just replace all the caps (related to sound/vid) while you have it opened.

/img0214ve4.jpg

[ColterF]

Duo R,

   Thanks for the advice, I figured I might a well get em all fixed, now my only concern is where to do it, I'm terrified it would result in some sort of explosion if I attempt it. I've never soldiered in my life, but buddies of mine have, on a scale of 1-10 what do you think the difficulty is for the job? I've opened it up and it all looks fairly accessible/

[Platinumfungi]

ColterF - If your friends can do quality work with a soldering iron then you'd be set. As long as they are familiar with small electronics it isn't a very difficult job.

Just make sure they know what they are doing and, if need be, have them practice removing/replacing caps on a broken pcb.

[pceslayer]

I found this forum over a year ago while scowering the web for a replacement laser for my original TGCD and I just wanted to say, Thank you guys!

I got a Turbo Express from a guy online as-is with 5 games for $30... Issue was Sound and backlight, but no video.

Wen't to radioshack and bought the cap and 20 min later I had a working turbo express!!

Thanks again!

[Platinumfungi]

I got a Turbo Express from a guy online as-is with 5 games for $30... Issue was Sound and backlight, but no video.

Wen't to radioshack and bought the cap and 20 min later I had a working turbo express!!

Thanks again!

Nice job  It's always very satisfying to repair something that's broken. That's a nice deal you got there too!

[PCEngineFX]

I have made this topic sticky, as well as changed the thread title for better classification.

[Duo_R]

thanks Aaron!

[Platinumfungi]

I have made this topic sticky, as well as changed the thread title for better classification.

Awesome. Thanks a lot!

[ColterF]

I spoke with Duo_R a few times and he was kinda enough to offer to fix my express. I shipped him the TE and for a very reasonable rate fixed all my caps AND my lousy torn run button. I couldn't speak highly enough about Duo_R, very nice, very fast and very professional. If you need your screen, keys, sound, caps fixed, Duo_R is the guy to pull it off.


  Thanks again Duo_R, I'm playing TE like it's 3rd grade all over again!

[Bludgeon]

Sounds like the deal to me and wondering already from whats been shown if my TE has the same video problem discussed here? It has a greenish hue and thats about as far as it gets. It would be nice if the TE guru here could fix it since the one thing I did the most on it was watch tv but since analog is no longer a viable source of video it might be nice to play Devils Crush on it once I find it again.

Blud

[DragonmasterDan]

I've yanked apart my TE and found the infamous cap in question. What's the best/safest way to remove it? Any suggestions. this will be my first attempt at a soder repair.

[DragonmasterDan]

I've yanked apart my TE and found the infamous cap in question. What's the best/safest way to remove it? Any suggestions. this will be my first attempt at a soder repair.

I tried solder repairing a game gear today. Unfortunately it didn't work despite looking good. I may hold off on this one for a bit.

[nat]

Man, the TE video fix couldn't be easier. Just make sure you get the polarity right, or you could really f--- things up.  Use a pair of needlenose to carefully remove the old cap (be gentle so you don't lift the traces off the PCB), then solder the new one in place. The location of the video cap makes the job particularly simple since it's right on the edge of the board and easy to get to.

[samson7point1]

Thanks for the awesome repair guide.  I snagged a practically brand new TE off of Ebay for $34 and managed to fix it with a $1 part from Radio Shack.

It got a little hairy there for a bit though.  I thought I was being careful but still accidentally pulled the negative trace off the board when I removed the capacitor.  Thankfully the trace ripped pulled up far enough for me to follow it to another solder point.  The leg of the little transistor/MOSFET that sits just adjacent to the cap will work. 

If I had it to do over again I would definitely have tried to touch the soldering iron to the legs and gently pry them up rather than trying to pull the cap off cold.


Looks so innocent just sitting there.


Disaster strikes!  I did not notice the little trace that was ripped out of the surface of the board at first - I honestly thought it was just a strip of paint or glue or something.  The scratches you're seeing where the pad for the negative trace was are my desperate attempts to find what the pad had been attached to.  I was hoping that if I dug into the board I would find another solder point.  I realize at this point that was silly, but at the time I had no idea.


But that was exactly what I needed to find an alternate soldering point.


Here is the alternate soldering point magnified some more.

I decided to remote-mount the cap because the connections, while solid, were so fragile I didn't want to risk any more bending and twisting than I had to.  It may not be pretty but it works like a champ.

[NecroPhile]

My turbo express is slow to power up, meaning the screen takes a little time to show clearly any ideas?

Dying capacitor(s).  Eventually it will never 'warm up'..... just like mine. 

[BlueBMW]

Similar problem on this same topic though.  What should one do if your screen works perfect, but the backlight progressively gets brighter the longer the unit is on, even though you've turned the brightness to the minimum?

[osmodiar]

I have done this and my video works but now it is slowly grows darker and darker and then cuts out. I have been at it for nearly a full 24 hours now. I give up! What to do next? anything? ugh!!

[BlueBMW]

I have done this and my video works but now it is slowly grows darker and darker and then cuts out. I have been at it for nearly a full 24 hours now. I give up! What to do next? anything? ugh!!

I guess your turbo express and my turbo express need to get together   Mine gets progressively brighter!

[osmodiar]

Well, interesting story about that. It did that too but then I replaced a couple other caps and now as it warms up it starts to flicker and get darker and darker until it simply shuts off.
So, I got the good one out of my personal collection which I had purchased new from tzd a number of years back. Just so I could feel god about playing one that I new to be working. I had only used it a handfull of times. I fired it up and much to my horror the sound was very low and as I allowed it to play further the screen got darker and darker but didnt shut off completely like the other one. So, I went and got some new caps. now with both the sound cap and the video cap in place my good one is now getting lighter and lighter. Holy crap!! I mean really! why is it that the coolest toys are always crap? I realize I am new on this forum but if anyone can help me out it would be greatly appreciated!

[BlueBMW]

I'll probably just start replacing every cap on the unit until I figure out which one causes the brightness issue

[osmodiar]

do you think it will be simply that? I see from the step by step at the beginning of this thread it says that the one that ended up correcting the issue was the last one that was changed. But given the troubles we are having it dosent seem that it is solely the culprit. so, replacing them all does make sense but ugh! what a job!

[BlueBMW]

I think the issue they were referring to was the backlight on but no video issue.  I suspect our backlight issues are tied to a different source, be it a bad cap or something else.

[nat]

The brighter and brighter issue usually means you are using sub-par (or almost dead) batteries. The Express seems to be finicky-- it wants good, quality name-brand alkalines to work right. It doesn't like any sort of rechargeables or non-alkaline sources.

[BlueBMW]

The brighter and brighter issue usually means you are using sub-par (or almost dead) batteries. The Express seems to be finicky-- it wants good, quality name-brand alkalines to work right. It doesn't like any sort of rechargeables or non-alkaline sources.

Looks like you nailed it!  It had some cheap off brand batteries in it, so I swapped in some fresh brand new energizers, and now it works perfectly!

[Duo_R]

i currently use nickel metal hydride rechargeable batteries with no problems, however i recall the manual saying to stay away from nickel cadmium batteries.

The brighter and brighter issue usually means you are using sub-par (or almost dead) batteries. The Express seems to be finicky-- it wants good, quality name-brand alkalines to work right. It doesn't like any sort of rechargeables or non-alkaline sources.

[nat]

I've never personally tried nickel metal hydrides in an Express, but I've tried [fully charged] nickel cadmiums and I only got about 6 minutes of play before the "brighter and brighter" syndrome set in.

[Duo_R]

yeah hydrides are legit, I get like 4 hours out of a set that I have.

[ApolloBoy]

I was replacing the cap on a TE and I accidentally pulled both solder pads while desoldering the old one. I can't find the traces they were connected to and I need to know what points I can solder to instead.

[Duo_R]

For which cap, the video one? Pix?

[ApolloBoy]

For which cap, the video one? Pix?

Yeah, it's the video cap. I'll see if I can provide a pic on Sunday, since I'm busy tomorrow.

[ApolloBoy]

Ack, wasn't able to get a pic, but I don't think I need one since both the pads for the video cap are gone. I need to finish this repair, so I need to know what other points I can solder the cap to.

[ApolloBoy]

Anyone?

[blueraven]

First we would need a photo. If you upload a picture, It would be easier for people to instruct you. Also if the pads are gone are the traces gone as well?

[ApolloBoy]

Finally got my camera to cooperate...

/zv1sic.jpg

[blueraven]

 ApolloBoy,

These are the two areas that you are going to want to focus on, the positive terminal for the video cap in the blue circle, and the negative solder-point for the capacitor that should be under the pink oval.



On the positive side; Inside the circle is what is left of the trace, I'm assuming. In the right-side of it, is that what's left of the copper trace that led to the pad? If so try to solder the positive side of the capacitor to this. If there is enough of the trace left, but you cant get the leg of the capacitor to attach to the delicate trace, solder a very thin wire like 24 AWG or smaller on one side to the trace and on the other side to the positive leg of the capacitor. If the trace is too far gone, try to attach the positive leg of the capacitor to the hole that I have highlighted with a black dot inside of the blue circle.

On teh negative side; Veeeery carefully scrape with a 1/16" screwdriver in the area under the pink oval. I did this on my express and I saw a solid copper line leading up to the pad. You may want to do the wire trick again. I'm not sure if this is a specific area where you need to ground the cap.

I hope this helps you get you system back online; people please chime in 

[Duo_R]

when I get a chance I will check my TE to see if there is another option.

[Duo_R]

Apollo did you see the post on page 5 where the same issue happened?

[ApolloBoy]

Apollo did you see the post on page 5 where the same issue happened?

I did, but that was only for one pad. In my case both pads were gone, so I wasn't sure what to do for the other one.

[Duo_R]

I used an ohmmeter, here is how the cap is connected. should just be able to wire up directly to these points.

/201011012101diagram.jpg
/201011012101diagram.th.jpg

[chop5]

this has poyplexed me. it looks like the right cap prong goes into the middle pin of that tiny voltage regulator on the far right but the left pin i cant figure out. i think it goes into the bottom of the board into that blue thingy. i need to see how the circuit flows.

but yeah this is a common problem with me. the smaller a cap is the greater chance of the whole pad either coming off or solder lifting up. The cap fluid eats away at it making it very brittle. the 4.7 and the 33 uf caps are huge problems. of course the 100uf caps are biger and have more solder so no problem.

The best way for me to remove one of these caps is to use a small screwdriver and gently rock the cap back and forth where it gives way till it frictions off.  if it leaves behind its old cap legs thats gold,easier to solder onto. flipping the motherboard to rest on the case makes it easier and wont harm it.



its takes about 15 to 20 minutes to rock it back and forth. it can move real fast like a blur but it gets boring but if you close your eyes and say the buddahist sutras the time will go fast.

i shape my caps legs for soldering first:



but apollo if the soldering welds are too tiny for you to do il do it for you for free. Solder paste or flux is like gold,makes tiny welds possible

[Duo_R]

15 to 20 minutes? Try five seconds with needle nose pliers. Just do the twist back and forth.