REPAIR GUIDE - TurboExpress: Sound Fix

[ltpitt]

Ok...

I admit: I've tried fixing my little buddy and I went from no sound to mono sound in earbuds and sound in speaker...
With a little background hum noise.

I've read that changing just the 1st capacitor of this thread could not solve the problem but it took me ages and the infinite fear to destroy my unit (I am clearly in love with it).

I've read of many forum users with a steady hand and a big heart that are willing to help their tongue-tied brothers to speak again

If anyone is in Europe probably's better (I live in Rome) so I can send the little baby with insurance without being forced to sell my house

[420GOAT]

i work around the corner from radio shack and was wondering if this cap is ok to use.


http://www.radioshack.com/product/index.jsp?productId=2102484

[thesteve]

that will work, but is not gonna be an easy fit

[chapel]

rad. I just yanked my TE out and noticed my sound was a bit low...

[Slypty]

  Thanks for the tip, but I'm still having no luck.  I pulled a few traces from the board since it had some real heavy oxidization.  I managed to do the mod well, and repair the broken pads to their traces. 

  Still no luck.  Not sure what else could be irking it, could I have a bad Amp? 

[Slypty]

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 for posting that part, I had done this mod and still have no sound.  I'm guessing broken trace somewhere, it's getting really frustrating.  I have the recommended Cap attached to the Op Amp, and the other one with equal Capacitance has a stripped trace pad.

  A quick question:  Would it be possible to attach BOTH Caps to the Op Amp?  Basically just to make a quick test to see that things are working?   I know there's 4 Caps but the one's that seem the most iffy on my end are the bigger one's.

[thesteve]

try the headset
if that works stop messing with the amp/caps

[mamejay]

Hi thesteve,
I have just recapped my friends one but still no audio at all from internal speaker.  I do get audio from the headphones.  There was some damage to the tracks on one of the caps.  Its the 100uf right next to headphone jack.
I traced the positive to pin 4 of a chip on the backside of the board and the negative just went to negative.
Any idea's about why no audio would be coming out or if there is something else I can try?

[thesteve]

the speaker hooks to the headset jack directly
the jack jumpers the speaker on when no jack inserted
the jack could be just dirty

[mamejay]

the speaker hooks to the headset jack directly
the jack jumpers the speaker on when no jack inserted
the jack could be just dirty

Thanks for that.  Can I possibly put a solder jumper to force the external speaker to work?  Just to confirm it is the headphone jack.

EDIT:
I bridged the points that are shown in page 1 of this thread and now I can get audio out of the speaker!!  So looks like it could be the headphone jack connector.  Any tips on cleaning that up or even a replacement that can be used?

EDIT once again:
More investigation has shown that the little gate inside the headphone jack is broken.  Now comes the tricky part.  Is there a replacement for one of these?  I have external audio now at least but would be good to get it back to fully working.

[thesteve]

It wa not an uncommon jack BITD, so it should be available

[mamejay]

Thanks for that.  Well if anyone has something please let me know.  I will keep an eye out for one.  I found one for sale on a retro website but I think the shipping for such a little thing will be a killer to Australia.