TOA 900 SERIES AMPLIFIER A-912MK2 PROTECT LIGHT
The unit features transformer-isolated outputs, and a direct output mode if non-transformer operation is desired. It is very frusterating all the cables are the right size its is a watt amp. Sometimes DC voltage stored on a capacitor nearby upsets the multimeter reading. Otherwise, the resistors are damaged I would say. 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. Note this amplifier uses a servo circuit op-amps M which work to keep the idling output at 0VDC. The AMK2 is designed for high performance with a low self-noise, a wide frequency response, and excellent output regulation.
Please see attached photo and let me know what you think. I have my DVM set to diode mode when testing. At CN I get a voltage reading of around Also tested many of the resistors and there are a few which are questionable to me. Is that a LOW-Z input? Instant Repair Help over the Phone 6ya.
Originally Posted by redwire Typically, shorted power amplifier transistors trip the DC protection circuit. One of the biggest reason why this happens is because the subwoofers are wired wrong. The output transistors, drivers, pre-drivers, emitter resistors I would test.
Helpful 0 Not Helpful Comment Flag. Posted on Jan 02, Amp is just telling you that its clipping and overheating due to the change in ohms of a shorted or bad speaker. Login to post Please use English characters only. One of your seriew may be bad. This is the connector that connects the condenser to the PCB. R is R on the schematic but pic serifs like 27R installed on this board???
I have two watt Modules allow configuration for all sources. This will cause a short and send the amp into protect mode. I am getting a reading on both at 1. A good amp never produce an over of 0. What is the voltage that is measured at L or where the two.
In Stock Update Location close. Be the first to review this item. That could cause it. If you can post the schematic you obtained, that would help. They have a square symbol next to them on the schematic. All times are GMT Originally Posted by redwire Note this amplifier uses a servo circuit op-amps M which work to keep the idling output at 0VDC.
Its also possible the amp is on its last leg due to heat. Find More Posts by Thedoc Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US. 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. The Knight Level 3 Expert Answers.
My toa a-912mk2 amp does not work and the red protect light stays on
I just cant seem to find it. 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. More Print this page Share this page. You can start at the power supply, the amp input, the output, the middle etc. 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. 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 have only done a basic visual inspection to ensure the issue isnt obvious checked fuses on board.
Hi there, Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two. This is another way to troubleshoot. I have my DVM set to diode mode when testing.
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 Electronics AMK2 W 8-Channel Modular AMK2 UL B&H
Find More Posts by Bterrier. At CNI get a voltage reading of Not Specified by Manufacturer. For further details see delivery estimates in cart.
Note the polarity of the voltage if it is not zero. Update Unrecognized Zip Code. You can’t post answers that contain an email address.
TOA Electronics A-912MK2 Stereo Amplifier User Manual
If the protection LED remains lit without remote voltage applied, the amp may have other problems. See attached schematics and troubleshooting guide. Some resistors used here are fusible types and look fine but can go open circuit.
Heat breaks down electronics part and eventually get worse. If a resistor in circuit reads higher than rated value, reverse your meter’s leads and see if the reading changes.