You can start at the power supply, the amp input, the output, the middle etc. At CN , I get a voltage reading of TOA series ii Amplifier PMK2 I also failed to mention that there is a portion of the board which appears to have possibly overheated. Don’t forget to order the input module separately if you need one. You may want to remove the pc board and check the solder connections, if the boards been running hot the solder can break down and cause poor connections, that might be whats wrong. If you can post the schematic you obtained, that would help.
It has a single module slot for easy custom configuration using TOA plug-in modules. Sometimes DC voltage stored on a capacitor nearby upsets the multimeter reading. Find More Posts by Thedoc For further details see delivery estimates in cart. Originally Posted by redwire Note this amplifier uses a servo circuit op-amps M which work to keep the idling output at 0VDC. Im wondering if somewhere within that area is the problem. TOA series ii Amplifier PMK2 If any of the voltages on the drivers were off, the amp offset would be off, and you said you measured 0 volts on L, Just to double check, measure the voltage on the white. If the output transistors shorted, the fusible emitter resistors 0.
I am getting a reading on both at 1. You can NOT look at a transistor and say it looks ok, you need to at least check them with a meter, even if the transistor is leaky or if a resistor is ie higher than its value is enough to unballance the amp and trip the protection circuit.
That circuit also drives seroes protection led That pc board has been running hot for a long time to do that, it did not just turn dark all of seried sudden. I just cant seem to find it. TOA series ii Amplifier PMK2 I also failed to mention that there is a portion of the board which appears to have possibly overheated. Send a link to this item so recipient can review, customize or exchange for an alternate of equal or lesser value. D gives me a reading of 0. The point is to be a detective and have fun.
TOA P-912MK2 900 Series Single Channel 120 Watts Power Amplifier
This is another way to troubleshoot. If OP can measure some voltages on the transistors, or just keep testing parts. Rated 5 out of 5 by Anonymous from Painless Best price. At CN I get a voltage reading of around All times are GMT I see TOA forgot protection diodes to the massive 70V line output transformer, so it’s not a tough design despite the reliability claims.
That could p-912mk22 it. There are about 5 diodes in total that I am getting questionable readings from, but again I am new to this so maybe I am not testing properly? I would keep checking parts. United States I’m a: I looked at a couple other schematics and R is shown as a 27 ohm It may depend on the version ‘A’ vs ‘W’ Here is another manual, schematic at the end.
TOA series ii Amplifier PMK2 – Badcaps Forums
Have you checked the thermal cutout listed p-92mk2 thermostat Check the voltages on M protection ic it also drives the relay. You may want to remove the pc board and check the solder connections, if the boards been running hot the solder can break down and cause poor connections, that might be whats wrong.
If you can post the schematic you obtained, that would help.
Please see attached photo and let me know what you think. TOA series ii Amplifier PMK2 The 3 pin resistors are just two resistors with a common center pin the single pin endthey should read. I have only done a basic visual inspection to ensure the issue isnt amplifiet checked fuses on board.
I also failed to mention that there is a portion of the board which appears to have possibly overheated. Find More Posts by redwire. Sometimes DC voltage stored on a capacitor nearby upsets the multimeter reading.
I tested the transistors which appear to be good. Module slot accepts a variety of plug-in modules for easy customizability Wide Frequency Response Low Noise and Distortion 25V, 70V, and 8 ohm transformer-isolated outputs Direct input for connection of an audio source Direct low-impedance output mode for non-transformer operation Selectable Input Sensitivity Protection circuitry for overload, short circuit and overheating Turn-on delay disconnects output at power-up Master volume control Status indicators for normal, clip, power, protect, and signal Includes volume control security knob Optional rack mount kits available.
Order in the next 0: Otherwise, the resistors are damaged I would say. Seriss new zip code to refresh estimated delivery time. It has a single module slot for easy custom configuration using TOA plug-in modules. Thanks, I will double check those resistors and reverse the leads to see if the readings change. International orders are processed the next shipping day.
And check continuity between L and relay contact where R connects to relay That will check the thermal cutout M drives the relay, the relay contacts are S1 that connect the amp output to the speakers.
Don’t forget to order the rack-mount kit separately as it is not included.