REPAIR GUIDE - TurboExpress: Sound Fix

[grahf]

Just replacing the single cap did not work for me. In fact, it made the sound stop working alltogether. The audio opamp NEEDS all four of those caps by design, but it just so happens that the one D-lite pointed out is most crucial for operation and will fix most peoples problems (but probably not 100%).

I dont think the screen can be replaced by replacing caps. The screen takes RGB input, and from my tests the signal comes almost directly off of the hu6260. Sounds like your screen itself is bad, and unfortunatly it probably cant be fixed. Old lcds like these are just really flakey.
When I have time, I have a modern LCD from a pocket tv that I plan on hacking to take RGB, and putting that in one of my Expresses. It will be nice to have a system with modern LCD.

[Tighe]

Just replacing the single cap did not work for me. In fact, it made the sound stop working alltogether. The audio opamp NEEDS all four of those caps by design, but it just so happens that the one D-lite pointed out is most crucial for operation and will fix most peoples problems (but probably not 100%).

I dont think the screen can be replaced by replacing caps. The screen takes RGB input, and from my tests the signal comes almost directly off of the hu6260. Sounds like your screen itself is bad, and unfortunatly it probably cant be fixed. Old lcds like these are just really flakey.
When I have time, I have a modern LCD from a pocket tv that I plan on hacking to take RGB, and putting that in one of my Expresses. It will be nice to have a system with modern LCD.

Actually in my case I tested the screen and it is functional, the problem is with the system board.

[nat]

Just replacing the single cap did not work for me. In fact, it made the sound stop working alltogether. The audio opamp NEEDS all four of those caps by design, but it just so happens that the one D-lite pointed out is most crucial for operation and will fix most peoples problems (but probably not 100%).

I dont think the screen can be replaced by replacing caps. The screen takes RGB input, and from my tests the signal comes almost directly off of the hu6260. Sounds like your screen itself is bad, and unfortunatly it probably cant be fixed. Old lcds like these are just really flakey.
When I have time, I have a modern LCD from a pocket tv that I plan on hacking to take RGB, and putting that in one of my Expresses. It will be nice to have a system with modern LCD.

Thanks to your post in another forum, I found out my GT isn't dead after all. The fuse was just blown. I  bypassed the fuse and all is well.

However, I uncovered a different problem. I replaced the one cap D-Lite mentioned but my aduio is still not working. In fact, it didn't help anything  at all. Looks like I need to replace the other 3 as well. Will you post those part numbers?

[grahf]

Yes, no problem. I ordered the replacement caps from www.jameco.com  You have to search by "catalog #".

You need two "193017". The originals are 33uf 6v, the jameco replacements are 33uf 16v.
You need two "192903". The originals are 100uf 6v, the jameco replacements are 100uf 6.3v.

Just a few pointers: you WILL need to pick up some desoldering braid for this job (radioshack). You have to remove the shields, and some of the posts are impossible to get to with a desoldering tool. A well placed piece of braid and fine tip soldering iron will make things easy. Also, it can be hard to get to the 100uf caps if your soldering iron isnt small enough. You can desolder the headphone jack for easier access. Its a lot more work, but it depends on what your working with. Good luck!
-Ben

[Torx]

WOOTTT!!!!  i just repaired mine!
man i got scared as heck, i accidentally got molten solder on the tiny little transistor rectangle thing and accidentally pulled it up a little..  i almost fainted..
then i heated it up and push it down..  put it back together with fingers crossed and it works great!!

thank you d-lite and others, when i got time and money i'll be replacing all of them..  but as of now.. the sound is great and loud!
i left the cap in just in case others are wondering..

i just hope this modfix wont have any ill effects in the future...

[nat]

My GT had audio that didn't work at all, not even with headphones. I ended up just replacing the one cap, which turned out to be a huge chore in itself. My hands are too large and unsteady to be working on a PCB that is so cramped and small. I blew the fuse in the process, which I luckily bypassed with no ill effects.

Anyway, after replacing the one cap, I now have loud sound over the headphones but the speaker is still dead. I'm going to leave it at that and call it good-- after reading what grahf suggests for replacing the other caps, I'm calculate an 85% chance of destroying my GT if I were to attempt it. Especially after the trouble I had with the "easy" one.

It's OK, because I would normally use headphones most of the time I played anyway.

[jimid2]

Well, I (well, a more technically adept friend of mine, actually) managed to get two of the caps replaced in my "headphones only" TE before giving up in nervous exhaustion - but it was enough! I've got sound!! Not loud enough to be heard on a bus, but plenty loud for playing on the couch in my home, even with the stereo on in the background. 

It's thanks to this post that I've got this far, and I wanted to say so! Mucho graçias!   

[rastoma]

Yes, no problem. I ordered the replacement caps from www.jameco.com  You have to search by "catalog #".

You need two "193017". The originals are 33uf 6v, the jameco replacements are 33uf 16v.
You need two "192903". The originals are 100uf 6v, the jameco replacements are 100uf 6.3v.

Just a few pointers: you WILL need to pick up some desoldering braid for this job (radioshack). You have to remove the shields, and some of the posts are impossible to get to with a desoldering tool. A well placed piece of braid and fine tip soldering iron will make things easy. Also, it can be hard to get to the 100uf caps if your soldering iron isnt small enough. You can desolder the headphone jack for easier access. Its a lot more work, but it depends on what your working with. Good luck!
-Ben

Hi Ben,

Thanks for the info.  Do you have extras of these?  Or does anyone here want to go in and buy them and split them? 

I know the cost is very cheap, it's not a matter of cost, I just hate wasting things or throwing something a way that's good.  I know I'll never use 10 each of these and only need 2 each as stated.

[ceti alpha]

  Wow! I don't have a TE, but all the effort you put forth in this area is amazing!  And your step-by-step guides are awesome. 

[Wolfeman]

Just replacing the single cap did not work for me. In fact, it made the sound stop working alltogether. The audio opamp NEEDS all four of those caps by design, but it just so happens that the one D-lite pointed out is most crucial for operation and will fix most peoples problems (but probably not 100%).

I dont think the screen can be replaced by replacing caps. The screen takes RGB input, and from my tests the signal comes almost directly off of the hu6260. Sounds like your screen itself is bad, and unfortunatly it probably cant be fixed. Old lcds like these are just really flakey.
When I have time, I have a modern LCD from a pocket tv that I plan on hacking to take RGB, and putting that in one of my Expresses. It will be nice to have a system with modern LCD.

Thanks to your post in another forum, I found out my GT isn't dead after all. The fuse was just blown. I  bypassed the fuse and all is well.

However, I uncovered a different problem. I replaced the one cap D-Lite mentioned but my aduio is still not working. In fact, it didn't help anything  at all. Looks like I need to replace the other 3 as well. Will you post those part numbers?

I have the same problem with my screen, can you post a photo of where the fuse is you're talking about?

[WoodyXP]

Thank you very much for posting this fix, Mr. D.  I was able to fix mine and it is LOUD!! 
My quality of life has increased immensely.   

And sorry for bumping this old assed thread.  :oops:

[nat]

I may have some information soon to add to this thread regarding the sound circuit. Stay tuned (pun intended).

[chop5]

thanks dean did the 1 cap soldered to the two VIA's,works perfect

[ceti alpha]

I may have some information soon to add to this thread regarding the sound circuit. Stay tuned (pun intended).

groooooaaaaannnnn!!! 

Who am I kidding? I love cheesy puns. 

[vestcoat]

Is anyone having problems with one of the stereo channels not working in the headphone jack?  Two of my 3 TEs have been fixed using D-Lites instructions but only output the left channel if I use headphones.  The third, with the common sound problem making the speaker so quiet it's almost inaudible, plays fine through BOTH headphone channels.