REPAIR GUIDE - TurboExpress: Total capacitor replacement chart

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I figured this would be as good a place for any to show Bludgeons Turbo Express! I took it apart yesterday and examined the board, it didnt look all that bad....until I started pulling caps off. 

EVERY SINGLE CAP LEAKED, even the one on the controller board...When Blud sent me the system it would not play video or sound at all...In fact I would go as far to say (although I didnt test) it may not of even turned on if I had tried. I ordered all High Temperature capacitors for the system from mouser.com (which now that I have used mouser I would recommend them over newark.com). They had every cap needed at good prices! Also shipping was I think 2 days from the night I ordered and it all came in one box unlike newarks two boxs that didnt arrive at the same time.

Well I got the caps in and went to town, I started pulling cap to find out how bad it really was! In the first picture of this post, I had all caps removed, you can see the electrlytic acid all over the board, it was glistening there was so much. After pulling everything off I went to the sink, filled with warm water and sprayed the board down with what seems to be a very good cleaning agent! I have used it on all the board so far and it does very well. The cleaner is called tough and gentle all-purpose cleaner. I cleaned the board with a toothbrush, rinsed and then stuck it in the oven for 15 mintues to dry!

15 mintues later...
Boards now clean and dry, I desoldered as much from the cap pads as possible, and then scrapped all of them with a flat blade x-acto knife. I then added flux to each pad followed by a soldering iron to kinda help prepare them. After all was clean, I reflowed solder on every pad, i had to go back and scrap a couple more pads to get the solder to flow on the full pad. Afterwords I applied flux again to the newley soldered pads.

Now its time to pull the caps out and figure the placement for them, so I start examining and cutting cap legs to fit the board. I soldering all the caps back together and cleaned the board one last time with a blast of air.

System goes back together for a test run......I notice that some caps are not allowing the system to fit properly at this stage. Popped some batterys in and tested the Turbo Express! Sucess!!!   The TE was loud and clear and video was working great!

Ok, now its time to take apart and figure out which caps need to be moved around....I figured it all out, recut and resoldered some stuff, added hot glue to spots that seem they may be trouble areas and to help secure some caps. System goes back together, all final pictures are taken....Now its time for a final test run. System is functioning correctly and plays well, sound is clear and crisp!

Ready for the pics and final video I made for Bludgeon? Im sure the suspense is building! lol

Well here they are, all high temp caps, I believe should be ok up to 105°C which converts to 221°F!

The three red circles were caps that were so bad they popped off by thumb pressure alone, the blue cap was the first I had replace but had leaked really bad:


Caps pulled board uncleaned:


Board cleaned and scraped:


Cap Pads reflown with solder:


Caps almost finsihed:


Rearranged a Cap or two:


Rearranged caps final:


Controller Board:


Front gaurd back on:


Back gaurd back on:


Final video for Blugeon:


Thanks goes out to Red Ghost for the visual guide to follow! Helped the process move faster! I noticed on this board there were only (6) 100uF 6v caps....Start to finish was 3hrs 30minutes! 

[Bludgeon]

To sweet. Can hardly wait to get my baby back and my Duo also. Thank you very much Override for ressurecting what I thought was a 300.00 paperweight. Now to see if the tv tuner still gets tv stations in. lol

[Duo_R]

nice job override, that is how I normally replace the caps but haven't seen one yet that needed a full swap. Oh and nice wifebeater.... LOLMAX

[Necromancer]

Another 'Express saved from the landfill.  Congrats on gettin' 'er sorted out and back in order. 

Oh and nice wifebeater.... LOLMAX

[blueraven]

You may remember my completely-narfed express from this thread:

http://www.pcenginefx.com/forums/index.php?topic=6971.0

Every cap in this Turbo Express was corroded and leaking, except for the 470uf cap right between the volume and tint knob. Although I was able to get the unit to boot once to watch Jeapordy with no sound before the digital TV switchover, it popped, fizzled, and went dead. The video caps faded, and the sound was non-existent even with earphones. The batteries were left in this thing for YEARS, and then it was left in a damp basement. 

I opened the TE, and found extensive rust residue that had collected in the bottom of the unit. The entire thing was disassembled, cleaned with 70% isopropyl alcohol and a toothbrush, fluxed and oiled. Upon disconnecting the board, I could already smell battery acid (that alkaline thing)

This is how the board looked after the capacitors were removed, and extensive cleaning.



The board is generally in pretty good shape. After cleaning and desoldering the board, It started to look good until the copper traces lifted away with the solder from their 10-year encounter with the battery acid. I make new traces with pieces of tinfoil and proceed.



The NTK 180° cap replacement went excellent as a general rule, with the exceptions of the three trouble caps; The to 100uf caps right next to the audio caps, and the one left video cap. In two of the three cases, I had to trace back to the hole, and solder the scrap-legs of capacitors directly into the trace hole and cross-hatch at 45-90 degrees to make a connection. The video cap was the worst.

You may also notice the discolored pin on the bottom HU6280 CPU chip, it was a huge rust deposit that covered 3 solder pins  and was cleaned upon initial assembly. 

Here's the finished board; with 47uf sound caps (teh Upgrad3Z! Little buggers are LOUD!) 



Special thanks to chop5, Override, and The Old Rover for bearing with me on this in shout! Also, thanks RedGhost for the diagram; the old Engineer guys at the electronics store were really impressed when they saw how thorough it was!

I cracked a Pabst and played Bonk's Revenge and Splatterhouse for the first time in 15 years last night. Even killed teh 6 batteries. 

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Im very glad to have been able to help ya blue! Congrats to another successful TE save!