I have a Lanzar Vibe 530 that I recently picked up because all the power supply mosfets were cooked. I replaced all the power supply fets and now the amp powers up and plays very well on all channels except channel 4. This is a 5 channel amp. When I hook a speaker up to channel 4 there is a spark when the speaker is attached even with no input to the amp. The speaker creates a strange low kind of slow oscillating noise. There seems to be a large amount of current going through the speaker with no real sound being produced. I'm guessing this is what really caused the amplifier to have a melt down before. Any suggestions on what to look at? I remember all the output fets checking out good.
If the output transistors (likely BJTs, not FETs) are all OK, you likely have a shorted driver transistor. The drivers are the small transistors near the output transistors. Since you have multiple other channels, compare the readings of the drivers in the defective channel to those in the good channels.
Set your meter to ohms or diode check. The amp should be disconnected from the power source while performing this test.
Set your meter to ohms or diode check. The amp should be disconnected from the power source while performing this test.
Thank you for the help. I checked all 12 BJTs. They all measure the same and none appear to be shorted. There are 4 other transistors near each pair of BJTs (A1695 / C4467). 3 are grouped together and there is one C3198 by itself. How should I go about checking these transistors? The board has 3 4558D OP AMPs. I have access to a scope at work but I dont know where to start. Any help would be greatly appreciated.
Ryan
Ryan
You check the smaller transistors the same way but you should check for shorts between all of the legs, not just the second to third. Compare the defective channel's components to the readings from the other channels.
Although the op-amps could cause DC offset, it's somewhat rare.
Check the drivers and let us know what you find.
Although the op-amps could cause DC offset, it's somewhat rare.
Check the drivers and let us know what you find.
I checked all the transistors and they checked out good. Upon further investigation I found the real source of the problem. The amplifier end of the board it bowed. It is bowed such that the signal in connector is touching the heatsink of the amp. If I pull the board away from the heatsink the noise goes away and the amp fork flawless. I'll try to take a picture of it. Stupid cheap Lanzar amp. I'm going to put a sheet of plastic under the board to insulate it.
lanzar vibe 530 power supply problem
i have a lanzar vibe 530 5 channel amplifier. 16 transistors and a few resistors have blown. however i cannot find the value of the resistors in order to replace them as i cant find a compnant diagram anywhere! therefore could you please send me a close picture of the curcuit board of the amp. i would very much appriciate this. cheers.
i have a lanzar vibe 530 5 channel amplifier. 16 transistors and a few resistors have blown. however i cannot find the value of the resistors in order to replace them as i cant find a compnant diagram anywhere! therefore could you please send me a close picture of the curcuit board of the amp. i would very much appriciate this. cheers.
lanzar vibe 530 amp
hi thanks for the reply. i am not sure where these blown resistors connect to, but i do know for sure that the mosfet transistors are fried on both sides of the curcuit board. what i can do is send u a close picture of the blown resistors in order for you to allocate which ones they are. thanks again mate for the early reply.
hi thanks for the reply. i am not sure where these blown resistors connect to, but i do know for sure that the mosfet transistors are fried on both sides of the curcuit board. what i can do is send u a close picture of the blown resistors in order for you to allocate which ones they are. thanks again mate for the early reply.
babin_perry@yahoo.com
Send me the photo. Zip the photos to one file before sending if you send more than one.
Send me the photo. Zip the photos to one file before sending if you send more than one.
lanzar vibe 530
alrite mate. i have found the bands of the resistors and i have put them in, but i have not yet got the transistors which are blown. at the moment i am in hong kong but i donnot have the amplifier with me, i am trying to locate some transistors in hoing kong as they will be cheaper then buying them from the U.k! is it possible if you could tell me the code of the mosfet transitors in the lanzar vibe 530 amp?
cheers mate.
alrite mate. i have found the bands of the resistors and i have put them in, but i have not yet got the transistors which are blown. at the moment i am in hong kong but i donnot have the amplifier with me, i am trying to locate some transistors in hoing kong as they will be cheaper then buying them from the U.k! is it possible if you could tell me the code of the mosfet transitors in the lanzar vibe 530 amp?
cheers mate.
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