Yamaha C-60 Woofer Pumping Problem

Found this for the IC107: https://www.ebay.co.uk/itm/M5220L-O...0ff820e:g:j6gAAOxy2CZTXk93&afsrc=1&rmvSB=true

thoughts on better sources ?

 

Mouser part number for D133

 

I don't know... Good chance of it being fake.

 

NZX13A is out of stock - will this work:
771-NZX13B,133

it's 13.1V instead of 12.9V

and about the IC107 - how likely is it hosed, could it be just the diode ?

 

You can try the diode first. NZX13B should be close enough. Replace D134 as well with the same.

 

going to hit local Fry's to see if I get lucky - what's my room in terms of parameters?
Vz > 12.9V
Pd 1/2W or more
Current 100nA
Impedance 35Ohms ?

 

Just the working Voltage and Pd--- 500mw at least.
12.4 vdc --- 12.9vdc <-------- HZ12-B2 and NZX13A

 

I think the D131 is also shot - this is HZ16-3L

 

Now ... am I doing this very wrong by testing the diodes in circuit ?

 

might as well..

In circuit is misleading.

 

Those that tested bad you need to verify out of circuit.

 

D133 is good out of circuit

 

and so are D129 and D131 - IC107 next ?

 

Lets measure all the voltages of IC107..
1.14.4v
2. 3.4v
3. 5.9v
4. 5.9v
5 -14.4
6. -6.0v
7. -6.0v
8. -4.0v
9. 14.4v

 

with new Zeners (D131/132: NTE5025A 16v, D129/130: NTE5012A 6.0v, D133/134 NTE5022A 13v)

1. -21.3v [output 1]
2. 4.2v [Inverted input1]
3. -5.9v [non-inverted input 1]
4. -5.9v [(-) power supply]
5. 5.9v [non-inverted input 2]
6. 5.9v [inverted input 2]
7. 4.1v [output 2]
8. 13.22v [(+) power supply]

 

The pin configuration on the M5220L spec sheet doesn't match the Yamaha schematic. Is a M5220L actually installed in the Yamaha?

Craig

 

Disreguard... Guess what I found another typo in the schematic...

 

Yes it is...I just got done verifying it on a parts unit I have not cannabized yet.

 

Everything about that IC on the schematic is FU.