So I ripped every single 3205 out of this thing because they were all shorted.. I still have 350ish ohms between ground and power. Is that acceptable. ?All the outputs seem alright but I should remove all the rectifiers to power up with the new 3205s right? Sorry it's been a while.. hope to hear from you perry. I've got a new digital oscilloscope coming in the mail tomorrow.. all my belongings were stolen ...yes basically everything I owned was stolen I finally have a good station built again... I don't know how I got buy without a desoldering gun! This thing is the ****.... I'll re-read your tutorial can you please send me the link perry . Thanks
Link to what, precisely?
Some of the amps of this type have a circuit that shuts down the PS driver IC if there is no rail voltage (rectifiers out of circuit) when the driver IC starts producing drive pulses. It's better to start without rectifiers but if you get no pulses, that circuit will have to be found and disabled.
Some of the amps of this type have a circuit that shuts down the PS driver IC if there is no rail voltage (rectifiers out of circuit) when the driver IC starts producing drive pulses. It's better to start without rectifiers but if you get no pulses, that circuit will have to be found and disabled.
I thought you had a tutorial you had written about amplifier repair.and how to use an oscilloscope....that is what I want the link to...my oscilloscope will be arriving today. I'll reply back as soon as it arrives... thanks
Oh did you ever get that banda viking schematic? I might know someone who can get ahold of one...
Page 73 of my car audio site.
https://www.bcae1.com/oscope.htm
The term 'tutorial' is taken as the one I sell for amp repair, not the online bcae1 site pages. That's where I was confused.
I did not get a full diagram but someone sent me some partial diagrams that helped me understand a bit more about it.
In the skar, did you check for drive with the rectifiers removed? You can determine if the pulses are likely there with a multimeter set to DCV. 5v at the gates of the FETs as well as at pins 9/10 of the driver IC indicate that you have drive.
What scope did you order?
PLEASE learn to use it withOUT using the auto mode. PLEASE.
https://www.bcae1.com/oscope.htm
The term 'tutorial' is taken as the one I sell for amp repair, not the online bcae1 site pages. That's where I was confused.
I did not get a full diagram but someone sent me some partial diagrams that helped me understand a bit more about it.
In the skar, did you check for drive with the rectifiers removed? You can determine if the pulses are likely there with a multimeter set to DCV. 5v at the gates of the FETs as well as at pins 9/10 of the driver IC indicate that you have drive.
What scope did you order?
PLEASE learn to use it withOUT using the auto mode. PLEASE.
I learned how to use one on an old school one which I'm afraid I liked having knobs better than this digital it just seemed easier..it was stolen unfortunatly. actually you taught me how to use it. When we were working on that rf t2500. Lol. The scope is a FNIRSI 1013D. I got the scope all calibrated I still have the rectifiers in. Should I remove them? And where do I start probing. ? Lol. Those banda vikings are really cool how they work... interesting...
First, remove the rectifiers and see if the amp will produce drive pulses at the gates of the PS FETs.
They don't allow people to sell anything here so you'll need to email me but I will post the following link for various files and information. The tutorial has reached a point where there are so many different file types used, so many required pieces of software (PDF readers, image viewers, 'office' type file viewers..., some working better than others) and so many different ways that the browsers handle them that you have two options, either install the recommended software (all of which work wonderfully) or fight through using the various files because multiple steps are required to open those files. They're readily available but take more than a single click to access them. Simply installing a browser that people don't normally use is a step too far and a deal-breaker for most.
https://www.bcae1.com/temp/!_READ-ME_if_you_want_to_view_the_Flash_files.htm
As a side note, if you're not willing to put in 100+ hours reading the hundreds (literally) pages of files, save your money.
For any other tutorial information, email me.
babin_perry@yahoo.com
As a side note on old-school scopes with wonderful clean, sharp, smooth CRT displays... If I had a chance to use a $100k digital scope or my old 465B, I'd pick the 465B for 99%+ of the time. Whoever designed the layout and the scope itself needs a Nobel prize in scope design. I'm not telling anyone to go out and spend money on a risky old piece of test equipment but if you get a chance to use one for a few days, do it.
They don't allow people to sell anything here so you'll need to email me but I will post the following link for various files and information. The tutorial has reached a point where there are so many different file types used, so many required pieces of software (PDF readers, image viewers, 'office' type file viewers..., some working better than others) and so many different ways that the browsers handle them that you have two options, either install the recommended software (all of which work wonderfully) or fight through using the various files because multiple steps are required to open those files. They're readily available but take more than a single click to access them. Simply installing a browser that people don't normally use is a step too far and a deal-breaker for most.
https://www.bcae1.com/temp/!_READ-ME_if_you_want_to_view_the_Flash_files.htm
As a side note, if you're not willing to put in 100+ hours reading the hundreds (literally) pages of files, save your money.
For any other tutorial information, email me.
babin_perry@yahoo.com
As a side note on old-school scopes with wonderful clean, sharp, smooth CRT displays... If I had a chance to use a $100k digital scope or my old 465B, I'd pick the 465B for 99%+ of the time. Whoever designed the layout and the scope itself needs a Nobel prize in scope design. I'm not telling anyone to go out and spend money on a risky old piece of test equipment but if you get a chance to use one for a few days, do it.
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Ok I have the diodes out "rectifiers". There is power to the led lit red.. . But I don't see any wave for coming from the ps pads where the 3205s came out... I see 12v at the drain pins and it ranges from 8.4v to 12v on the gate pins....0 on the source pins... .
It sounds like you have defective PNP driver transistors? Do you have a square wave on pins 9 and 10 of the 494?
494, DCV on pins 14, 15 and 16?
If you have the tutorial, read through item #44 on the PSTS page.
If you have the tutorial, read through item #44 on the PSTS page.
You didn't say if you had the tutorial so as a shortcut, lift pin 16 (to break its connection to the board) of the 494 and connect that pin to pin 7 of the IC.
Do you now have output pulses?
Do you now have output pulses?
