Marantz PM7200 Amplifier Repair (With Audio Tutorial)
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- Опубліковано 7 вер 2024
- Fault
Amplifier in protection mode.
Dry solder joints on multiple circuit boards.
All re-flowed.
Speaker protection and power start up relays replaced.
User controls and switches cleaned with De-Oxit.
DC offset set to 0 millivolts and AB Bias to 18 millivolts and class A Bias set to 90 millivolts.
Amplifier fully tested working correctly.
thats twice you have mentioned the quality of NAD parts, food for thought.
Yes the NAD C320 and C370 that use J H brand capacitors
Bạn có thể chia sẽ mình cách vào xem sơ đồ được không .máy pm7200
Yes email audioamplifierservicing@aol.com
Hi thanks for the great video. My PM7200 does power up anymore. I push the on/off button but it’s completely dead. Power light doesn’t come on. There is voltage going into the power board. Fuses are not blown. But there is already no power at the main transformer. Any advice? Thanks!
@NewYork-zg9iu The start up relay 5202 should energise providing power to the power transformer. Check if you have the 5.6 volt start up voltage, on the output of regulator 7302. The model of Amplifier develops a of dry solder joints on all circuit boards so depending on what you find bad solder joints should be reflowed.
@@AudioAmplifierServicing thank you so much for the advice! Will try it.
@@NewYork-zg9iu Take your time to clean the contacts and lightly brush the contacts with the fibre glass pencil.
You can also spray the contact cleaner onto an absorbent cloth and draw across the contacts.
It import not to bend the contacts when cleaning.
Also use eye protection when using the fibre glass pencil to avoid fibers flicking into your eyes.
@@AudioAmplifierServicing the output of the regulator is only about 250 mV. Solder joints look optically good. Could it be a capacitor or transistors in the regulator circuit?
@@NewYork-zg9iu Hi check if you have DC Voltage on either side of resistor 3207 1 ohm the voltage regulator input should be 13.3 volts. R3207 may be open circuit or the start up transformer thermal protection fuse may have failed you should have AC volts on the output pins of the transformer 5205
hi, this was great overview thank you. What would cause a humming when you turn one of these on ? no sound just a hum
When you say hum do you mean the huming sound is coming through the speakers or you can hear a huming sound from inside the Amplifier with no speakers connected.
Very interesting videos please keep these coming👍
I ve just picked one of these up that needs abit of attention speaker relays and probably a re cap, one thing it does need is the main on/off switch you hear it sparking internally ehen you gently touch the on/off button. Do you know what type of switch i need and wheres best to obtain one ?
Thanks 👍
Hi if you can send a photo of the switch to audioamplifierservicing@aol.com I will be able to advise a correct replacement
Hi, Where can I source these speaker protection relays in the UK?
Hi uk.farnell.com/schrack-te-connectivity/6-1415546-5/power-relay-dpdt-24vdc-8a-tht/dp/3792630?gross_price=true&srsltid=AfmBOoqTqtd6H-fv2EXn98DQh6Jcgo7v9HhXBXETNvH0hBmpVW06iQdy06w
@@AudioAmplifierServicing Many thanks - You are awesome!
@@AudioAmplifierServicing Purchased these relays but now I have removed the old ones I notice they were double pole single throw whereas the replacements you recommended are double pole double throw - Is this correct and you just cut of the unwanted terminals or is this an error?
Hi first of all thanks for great videos. I have an issue with my marantz pm7200, in direct mode the right hand speaker is slightly louder than the left.I had it repaired a couple of months ago it had to have two new out put transistors don't know which channel though. Any help would be appreciated.
Hi I have responded to your direct email.
hi.i have arcam avr 350.the displays do not work. everything else works. how can I fix the displays myself at home so that it shows the sound level and the radio station ..?. I'm not advanced in repair.
Hi Down load the service manual www.hifiengine.com/manual_library/arcam/diva-avr350.shtml then check the supply voltage to the vacuum fluorescent display.
Maranzt PM6004 likes to turn itself off when the volume is turned up
Hi can you check when the issue occurs do you see the mute LED on the front panel flashing, if so the protection system is operating.
In the first instance check your speaker wiring / connections and impedance. If no issue is found and the Amplifier returns back to normal operation, turn up the volume and see if the standby LED turns on and off If so there is an issue with the power Amplifier stage or the internal capacitors across the speaker terminals internally component references C7501,C7502,C7503,C7504