Wondering what would cause all the negative rail caps to explode ?
I checked the power supply fets,outputs, and everything checked done it’s just the rail caps that exploded. They are 1000uf 80v
I checked the power supply fets,outputs, and everything checked done it’s just the rail caps that exploded. They are 1000uf 80v
This is typically due to the low side FETs not being driven correctly. It appears similar to the Q124/125 failure in the 'type 2' amps (for those with the tutorial).
The snd transistors appear to have run very hot in this amp .
1 of them is marked G1 the other one looks like 79T any idea what the transistors are ? Part number
This is the best pic I could get of them .
When replacing them should I also replace the IRS2092S driver ic ?
1 of them is marked G1 the other one looks like 79T any idea what the transistors are ? Part number
This is the best pic I could get of them .
When replacing them should I also replace the IRS2092S driver ic ?
Attachments
Q50B,Q51B and Q52B are 2n5551
Q50C,Q51C and Q52C are 2n4351
The 2N5551S (SOT-23), DXT5551 (SOT-89), DZT5551 (SOT-223), KST43 (SOT-23), KST5551 (SOT-23), MMBT5551 (SOT-23) and PMBT5551 (SOT-23) is the SMD version of the 2N5551 transistor
The FMMTA55 (SOT-23), KST55 (SOT-23) and MMBT4354 (SOT-23) is the SMD version of the 2N4354 transistor
hope this helps
Q50C,Q51C and Q52C are 2n4351
The 2N5551S (SOT-23), DXT5551 (SOT-89), DZT5551 (SOT-223), KST43 (SOT-23), KST5551 (SOT-23), MMBT5551 (SOT-23) and PMBT5551 (SOT-23) is the SMD version of the 2N5551 transistor
The FMMTA55 (SOT-23), KST55 (SOT-23) and MMBT4354 (SOT-23) is the SMD version of the 2N4354 transistor
hope this helps
Just got new rail caps put in the amp .
When I go to check drive on the outputs i get nothing .
I tested for audio also and amp has no output .
I’m getting + - 68 volts of rail and +- 15 volts on opamps .
Any ideas where to start looking ?
When I go to check drive on the outputs i get nothing .
I tested for audio also and amp has no output .
I’m getting + - 68 volts of rail and +- 15 volts on opamps .
Any ideas where to start looking ?
See post above . I also noticed I have 2.33 volts measured directly across the speaker terminals.
Ok I think I figured out the problem .
The smd transistors all read shorted and it appears they ran hot .
I will order new and replace them and test it
The smd transistors all read shorted and it appears they ran hot .
I will order new and replace them and test it
Anyone know what I can replace the driver transistors with ?
The MMBT4354 is obsolete
The mmbt5551 I can’t find any in stock
The MMBT4354 is obsolete
The mmbt5551 I can’t find any in stock