u/TheRiflesSpiral

SOLD

Enjoy in good health, Throwaway_09298

~~Hey, y'all~~

~~I used my Titan 2 for a few months and didn't really care for it; I've come to the conclusion that nothing will ever be a BlackBerry again and I'm tired of getting the next best thing.~~

Anyway, it's in perfect condition. It comes with everything but the charger. (Left in a hotel room in Rothenberg, Germany. No regrets.) There's no screen protector on it, but it comes with a spare you can put on.

~~I'm looking for $350 US or if you have a smartwatch to trade... the music version of a Garmin forerunner watch, or a Samsung Galaxy watch, or maybe a Google Pixel watch, I'd be up for it.~~

~~Transaction will be handled via eBay or Vinted or another marketplace where we're both protected. Not looking to scam or be scammed.~~

This is a follow-up from this post: Damaged Zener - speculation on why? : r/audiorepair

Here's the schematic I'm working with: AudioSource AMP THREE

I received the replacement diode and put it in the circuit. The voltage ahead of the diode is still low for some reason; I've removed the replacement diode and tested it and it's still good... whatever's wrong didn't blow it.

I have two of these amps; on the good one, the voltage at the front of the diode starts at 0 then rises over the course of about two seconds to around 5v. That's what turns on Q37 and Q46 to disengage the protection circuit.

On the amp I'm troubleshooting the voltage starts at 0 then only rises to 2v.

I can't identify a reason the voltage at the C17/D14 junction would only be 2v... I've verified that Q38 and Q40 are both off (as they are on the good amp) but I have to admit I don't clearly understand what's going on in Q1/Q19 land.

Where should I be looking for failures here?

Titan 2 for Sale (or trade)

Replacing Zener didn't help. Following up...