Good day brothers. I just received this amp B2 mono from a friend but no model written on it. I checked it and found out no gate drive signal at Hi and Lo banks. Power supply section is normal and rail voltage +53 and - 53 are present. Actually the driver chip was located under the blue capacitor which I relocated it and connected it with red wire as shown in the picture. I did this in order to check the drive signal from the Driver chip U9. As I did, tracing backward from Fets gate, there are no drive signal from the chip itself. But my problem is that the part number of the drive chip U9 was erased due to heat I believed as well as the adjacent chip U10. As I traced, the Lo signal out is Pin 1 and Hi signal out is Pin 8. Can anybody tell me the part number of the chips U9 and U10 as shown encircled in yellow. I can not find any model written in it on the amp. . Thanks in advance bros.
Heat didn't cause the surface to look that way. The manufacturer defaced the ICs to prevent the amp from being repaired. In some cases, they'll actually change the part number on the IC to further confuse you.
I don't have any definitive information on these bit the larger IC may be an IR2010 and the other a CD4093.
Don't replace them without further troubleshooting.
Do you have the 12v above the negative rail on the VCC pin of the larger IC?
I don't have any definitive information on these bit the larger IC may be an IR2010 and the other a CD4093.
Don't replace them without further troubleshooting.
Do you have the 12v above the negative rail on the VCC pin of the larger IC?
Following IR2010 pins measured above negative rail
Pin 3 : VCC = low side supply = 12.1 v
Pin 6 : Vs = Hi Side supply return = 59.8 v
Pin 7: Vb = Hi side floating supply= 65 v
Pin 11: Vdd = Logic supply = 12.1 v
Pin 3 : VCC = low side supply = 12.1 v
Pin 6 : Vs = Hi Side supply return = 59.8 v
Pin 7: Vb = Hi side floating supply= 65 v
Pin 11: Vdd = Logic supply = 12.1 v
Is D10 connected between the VCC and the VB terminals?
Are the ICs in the preamp section defaced? If not post a photo that's good enough to read the numbers on them.
Post the DC voltage on all terminals of T10.
Are there any ICs on the bottom of the board?
Are the ICs in the preamp section defaced? If not post a photo that's good enough to read the numbers on them.
Post the DC voltage on all terminals of T10.
Are there any ICs on the bottom of the board?
Yes D10 is directly connected between Vcc and VB.
T10 Terminals respect to gnd (-)
B = 0 Vdc
C = -52.7 Vdc
E = -1.37 Vdc
There are no ICs at bottom of the board.
As shown in the picture Except U5 and U6 which are defaced all op amps are 4558D.
T10 Terminals respect to gnd (-)
B = 0 Vdc
C = -52.7 Vdc
E = -1.37 Vdc
There are no ICs at bottom of the board.
As shown in the picture Except U5 and U6 which are defaced all op amps are 4558D.
As I tried resoldering the driver chip and the parts around it. I was lucky that I got the signal now on the gates of the Hi and Lo output Fets , but now when I feed a 50hz input signal I don't get the sine wave in the output terminals , but I get the squarewave signal before the output inductor. I think the amp is not modulating as i don't see any difference in the signals of the output FETS when i apply the 50hz signal. I can't find any deffective parts around the driver chip. Could be Opamp issue?