Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69D)

[Electronic Santa]

Would these low ohm resistors make one of your output drivers (TTA5200) have low ohms between collecter and emitter..? It's a total PA Bluetooth board driving 15 inch driver It a NPN PNP output

It had blown outputs so I replaced but this low ohm reading is making me think they will blow again? I couldn't find anything else blown or short I think these low ohm emitter resistors are Messing with me.

1 is showing over 1meg emitter to collector the other looks short diode mode 0.069 and 96ohms

Is this normal?

[petehall347]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

check drivers and check power supply

[Electronic Santa]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

Checked both. The power supply is right on the audio board it checks fine

Should I be seeing that low ohms reading ?

[eccerr0r]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

usually no, they're in series. If you're in doubt, pull it out!

[Electronic Santa]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

And then what? I can't find any other symptom.

[eccerr0r]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

test them individually out of circuit if you're not sure. When testing in circuit you always get side paths. Whether they are relevant requires careful tracing of the circuit.

[redwire]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

It's never as simple as replacing one output transistor.
Base resistor R43 100Ω looks blown which means the green guy is shorted. The emitter resistor looks cracked as well.
How is R42 100Ω for Q25 TTC5200, did it fuse?
Spend some time checking the driver transistors as well. 2SD669A usually gets taken out too.

[Electronic Santa]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

R43 is reading .500M ? I guess that's not correct.

I'm going to check some of your other points.

[Electronic Santa]

Re: Emitter resistors in class AB amp board question (total PA bluetooth)(audio IPA69

Redwire, you were correct. R43 was cooked fell apart basically. I pulled the emitter resistor and it was open. So both those parts have been replaced still nothing.

The 2sd699a has some weird readings so I'll pull it and do a test.

There are 3 bridges in here and from what I can see, there is a plus and minus 50vdc, a 20vdc and a 6vdc. Nit sure if thays correct.

I'd love to find a schematic for this IPA69D-AMP-V6. Anyone have one?