to my knowledge, there is no service manual for the ma240.
I am repairing a z140 and the only document I found
and the manual service of the T40 which has a bit of the same circuit.
you'll find it here, you can compare with yours.
MYRYAD SYSTEMS T-40 INTEGRATED AMPLIFIER 1982 SM Service Manual download, schematics, eeprom, repair info for electronics experts
I am repairing a z140 and the only document I found
and the manual service of the T40 which has a bit of the same circuit.
you'll find it here, you can compare with yours.
MYRYAD SYSTEMS T-40 INTEGRATED AMPLIFIER 1982 SM Service Manual download, schematics, eeprom, repair info for electronics experts
by experience,check the underside of the pcb,it is very hot under there.
mine is very beautiful above but cooked below
You called it. Looks like quite a few transistors have burnt out. I’ll have to order a solder sucker today.
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also controls the regulated supply
I didn’t realise there was a regulator. I’ll go through it all tonight when I have more time, thanks again
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Ok then, so I’ve ordered a soldapullt. The Ouputs seem fine the bad ones are a1479 and c3789, I’ve found this link 2SA1479 p-n-p transistor complementary npn, replacement, pinout, pin configuration, substitute, marking A1479, equivalent smd, datasheet that has replacement suggestions at the bottom. What would you suggest maybe? I suppose the question is why would they have burned out? Too hot, over powered?
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Hi, my previous order didn’t go through so I’m putting in a new order today. Solder pump, Capacitor for another project FSP, Bnc to crocodile test lead for signal gen, 8 ohm 150 watt dummy loads and new transistors for my busted amp. Thank god for the old chip amp.
So the transistors that need replacing are before the pre drivers, input pairs or something. I’m not sure exactly there function but they are: 2sc3790 D and 2ca1480 D. I’m attaching a screenshot with details.
Any suggestion for a substitute would be greatly appreciated.
So the transistors that need replacing are before the pre drivers, input pairs or something. I’m not sure exactly there function but they are: 2sc3790 D and 2ca1480 D. I’m attaching a screenshot with details.
Any suggestion for a substitute would be greatly appreciated.
Attachments
Would anyone like to help me save my amp?
I’ve replaced the regulator Q504 - 503, 505, 506. Q501 and 502. Please see pictures, any advice on how to find the fault please.
I’ve replaced the regulator Q504 - 503, 505, 506. Q501 and 502. Please see pictures, any advice on how to find the fault please.
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