PG titanium 600.2 - Fixing a burned amplifier (edited)

[jcarron2]

Hi All

Would anyone be able to help, I'm badly need of a schematic of my titanium 600.2 amplifier. The supply circutry to the LM7815 has burned up, and I've reconstructed what I can from the similar supply to the LM7915 but there is still some problems, and I suspect something is drawing too much current !

Would anyone be able to help, or have some diagram for a similar amplifier? I'd imagine the 400 and 800/1000's share similar circutry for the 7815/7915 section?

Edit: Fixed title as it better describes what I'm trying to do.

thanks a mil

Jonathan

[jcarron2]

Hello

I should mention, I don't know the history of this amplifier except that it was fixed once before. I bought it broken, hoping to fix it.

I am attaching some progress I've made in fixing the amplifier. I have been able to power it on, and suspect there is still a component at fault (SF304), but need some assistance with the circutry....

I have noticed two voltage regulators provide power for the pre-amplifier and low power components. These two voltage regulators take power from the output of the two bridge rectifiers. The LM7915 side is OK, drawing 200 mah. The 7815 side is where Im experiencing a problem. The draw on the 7815 is 20 ma, if I disconnect the output on the 7815, and use an external 15V source, I can power up the amplifier now. It works but has a buzz on silence.

The feed for the 7815 as best I can tell comes from (refer to my poor diagram - im not a professional , and this board is REALLY hard to follow traces on! - hence the scraping to see)

1. + on 7805 comes from one of the "sides" of the coil. The ground on the 7815 comes from a resistor network which connects back to the "+" on the SF304. There are also 33 volt zeners accross the input on the 7815.

2. I have replaced and reconstructed as best I can what I believe to be there, but find the resistor network to the 7815 gets very hot when I pull about 20 ma from the 7815.


Observations

- I read from the SF304 "+" to the CT and observe 114 volts, and the SF304A from "-" and observe less.

- The SF304 reads about 400 ohm between the outter pins and the "+" center pin. In reverse it reads open - as I expect it should.



At this point I'm sort of out of ideas and thinking of replacing it, as I have a hunch one side is gone, causing the buzzz I hear but have no way to back it up.

Also if anyone knows what "kdc 125" means ... if it is indeed a capacitor or not? I'd like to put that back too, mine melted into a pile of gooup.

Can anyone offer some suggestions on how to proceed?

thanks

Jonathan

[Mr. Wild]

Oh boy, what a mess!

I don't think any schematics have ever been published by phoenix gold, so you have to rely on their techs for complicated repairs.

I personally would have no hope trying to fix damage like that.

[jcarron2]

Yeah, It's definately a mess. That area seems to be cooked pretty good, and left little of the existing traces to figure out exactly what was going on... It's a bummer they no longer exist; even talking to their techs now seems like a distant possibility... .

From searches there was chit-chat of burned boards, I sort of assumed this happened frequently when people don't read the manuals or abuse the product...

I am thinking of just replacing the SF304 on pure speculation... I don't really have much else to go on.

Any suggestions on anyone whom I could contact who may have some pictures or idea how this should be wired up?

thanks,

Jonathan

[ttocs]

Sorry but the schematics that has been compiled does not include that amp. Maybe Valeks1 could help you better, sometimes he will help via email I think otherwise he is a great tech to fix it for you.

[jcarron2]

Thanks for the info!

I've send him a msg, so we'll see. In the mean time I kept digging. Discovered the little daughterboard with the INputs and Aux Out is drawing about 60 ma, at 30 volts. From what I've been told the output from the voltage regulators will do about 20-30 ma @ 30 volts with the resistor configuration dropping the voltage before the Zener diodes.... so it seems in a sense I've found where the problem started. I can get the +30 volts but when I connect pin #1 and 5 (+ and - ) to the daughter board the 30 volt supply instantly drops to ~8-13 volts and I can feel those load resistors heating up real fast.

I've verified the 30 volt power supply will 30ma load (1k ohm resistor over the output and it holds 30 volts (30/1000 = 0.03 amps)

Daughter board pinout so far [ 1 2 3 4 5 6 7 8 ] * 8 is most rear/edge connection (my best guess so far only)
1= +15v
2= ? somehow related to amp power up
3= ? somehow related to amp power up
4= ? somehow related to amp power up
5= -15v
6= 3 tri-blue led & OP-amp power
7= ??audio signal
8= ??audio signal

Anyone have a cooked titanium series amplifier with the little daughter board they'd be willing to part with ?!?!!!!!!!

Thanks for any help / info /advise!

edit1: update pinout
edit2: have changed all caps on the crossover board, still no luck. Need to check the OP amps / DIF amps, beyond that possibly consider just feeding it the ~60 ma @ 30 volts and calling it a day.

Jonathan