That could cause it. Otherwise, the resistors are damaged I would say. Originally Posted by redwire. 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. Let’s go with R as 27R sch typo is R and look for trouble elsewhere. 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?
This is the connector that connects the condenser to the PCB. Order in the next 0: Have you checked the thermal cutout listed as thermostat Check the voltages on M protection ic it also drives the relay. Don’t forget to order the rack-mount kit separately as it is not included. The 3 pin resistors are just two resistors with a common center pin the single pin end , they should read. Send a link to this item so recipient can review, customize or exchange for an alternate of equal or lesser value. Enter new zip code to refresh estimated delivery time.
Don’t forget to order the input module separately if you foa one. Note the polarity of the voltage if it is not zero. The system also amlifier a direct input so that it may be used without an input module. I have my DVM set to diode mode when testing. Originally Posted by redwire Note this amplifier uses a servo circuit op-amps M which work to keep the idling output at 0VDC. All times are GMT I tested the transistors which appear to be good.
It has a single module slot for easy custom configuration using TOA plug-in modules.
The PMK2 has a selectable input sensitivity to accommodate high or low inputs levels, a low cut switch to limit low frequency response, a master volume control, indicators for normal, signal, power, ampoifier, and signal, and a turn-on delay which disconnects the output during power-up to prevent shock to the speakers.
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P-912MK2 Power Amplifier
Normally at idle you have 0V DC at the loudspeaker terminals, unless transistors have failed. 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.
I also failed to mention that there is a portion of the board which appears to have possibly overheated. The time now is See any errors on this page? Originally Posted by redwire Typically, shorted power amplifier transistors trip the DC protection circuit.
Find More Posts by Thedoc Page 1 of 3. I ampljfier cant seem to find it. R is R esries the schematic but pic looks like 27R installed on this board???
Don’t forget to order the rack-mount kit separately as it is not included. Order in the next 0: The point is to be a detective and have fun. At CNI get a voltage reading of I ampifier keep checking parts.
If OP can measure some voltages on the transistors, or just keep testing parts. 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?
Im wondering if somewhere within that area is the problem. Module slot accepts a variety of plug-in modules for easy customizability Wide Frequency Response P-9912mk2 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.
PMK2 | TOA Corporation
Note this amplifier uses a servo circuit op-amps M which work to keep the idling output at 0VDC. Or you can take more voltage readings with the amp powered on, carefully at each transistor and write them down. This is another way to troubleshoot.
The output transistors, drivers, pre-drivers, emitter resistors I would test. It looks like the same family or or just different power output. Also I did disconnect some connectors one at a time from the mainPCB to see if I could isolate the issue. United States I’m a: I could not find a service manual or schematic for the “P” series, but did for the “W” series wall mount and “A” series, like AMK2 which may be similar. Let’s go with R as 27R sch typo is R and look for trouble elsewhere.
What is the voltage that is measured at L or where the two. Rated 5 out of 5 by Anonymous from Painless Best price. 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. TOA series ii Amplifier PMK2 The 3 pin resistors are just two resistors with a common center pin the single pin endthey should read.
There are many different approaches to fixing audio power amplifiers.
That could cause it. I am getting a reading on both at 1.
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