Hi!
Just got another Turbo Express to fix! Would not power on etc.
At first I thought this was another capacitator-job as the previous one. But this TE had already been re-capped. Not the greatest job but ok.
Colour markings on the new caps also indicated that they had been re-checked some time later. And it became obvious why - the fuse was gone.
Since I didn't trust the cap-job of the previous owner I removed them all, cleaned the pads (still some "fishy smell" there) and put new caps in. I have done this before and it worked just fine! Also in went another fuse (1A, 125V).
Next I put in a game and powered it on. Sound would play, but only a white display. Which started to flicker and then the TE went out again - fuse burned. And Q900 or Q901 (marked DF 0H) - not sure which - got very hot! (Touched it accidentally.) Not good!
I put in another fuse and switched it on - this time without the upper half. Fuse gone again, Q900 or Q901 very hot.
Now I'm pretty sure that I have done a proper job, so I don't think it's the caps. Since I have a second unit I tested the upper half of the Turbo Express (with the display). Works fine, screen and sound are working properly.
Any ideas where to look for the problem? Is this a short? Or could it be a voltage regulator?
Pictures required? Just ask!
Addendum:
Q900/Q901 are transistors (2SD1898) for the backlight!