OK, typed a nice long post only to get sent back to the login screen when posting...
Anyway - short version, bought a 200ix on eBay 3-4 years ago from reputable seller. Never tested amp until today (I know, dumb...). Just saw the tamper stickers were torn, so I decided to take a peek and found this atrocity:
Click for high res of full board - great for zooming in
All I found was a PDF schematic, not a PCB layout and am having a little trouble reading it.
I'd like to salvage this amp - it has some brothers to play with...
Any guidance would be greatly appreciated!
Anyway - short version, bought a 200ix on eBay 3-4 years ago from reputable seller. Never tested amp until today (I know, dumb...). Just saw the tamper stickers were torn, so I decided to take a peek and found this atrocity:
An externally hosted image should be here but it was not working when we last tested it.
Click for high res of full board - great for zooming in
All I found was a PDF schematic, not a PCB layout and am having a little trouble reading it.
I'd like to salvage this amp - it has some brothers to play with...
Any guidance would be greatly appreciated!
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It also looks like but hard to tell because the flash from your camera on the board that your driver transistors for the power supply are burned.
I cant tell for sure these are board location Q2, Q3, Q4, Q5.
These will have markings of 1A or 1AM and the others will be a 2A.
The 1A or 1AM will be part number: MMBT3904
The 2A will be part number : MMBT3906
Does the amp power on or produce audio?
I cant tell for sure these are board location Q2, Q3, Q4, Q5.
These will have markings of 1A or 1AM and the others will be a 2A.
The 1A or 1AM will be part number: MMBT3904
The 2A will be part number : MMBT3906
Does the amp power on or produce audio?
Set your meter in ohms with the range on auto and measure the rsistance between the gate and source legs of all 4 power supply fets. That would be leg 1 and 3 looking at the fet from left to right, what do you get?
The board location of these fets is Q10,Q11,Q6,Q7
Next measure the gate drivers resistance the little smd resistors marked 510 what do you get? These are 51 ohm and should read somewhat close to that.
The board location of these resistors is R31,R36,R32,R37
The board location of these fets is Q10,Q11,Q6,Q7
Next measure the gate drivers resistance the little smd resistors marked 510 what do you get? These are 51 ohm and should read somewhat close to that.
The board location of these resistors is R31,R36,R32,R37
As a side note...
On this site (and others), if you type anything that would take more than 1 minute to re-type, highlight the text and copy it to the clipboard (ctrl-c or right-click and select copy) before clicking anything that will move you from the page where you typed it. It's happened to me so many times that I always do this for long posts.
On this site (and others), if you type anything that would take more than 1 minute to re-type, highlight the text and copy it to the clipboard (ctrl-c or right-click and select copy) before clicking anything that will move you from the page where you typed it. It's happened to me so many times that I always do this for long posts.
Here are the values:
Q10 - 7.35 m ohm
Q6 - 7.34 m ohm
Q11 - 7.25 m ohm
Q7 - 7.24 m ohm
R31 - 51.1 ohm
R36 - 51.1 ohm
R32 - 51.0 ohm
R37 - 51.0 ohm
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Most sites (that I visit anyway) don't timeout that quick anymore - I've run a number of forums over the years and that value is one of the first things I change.
I just need to keep it short and sweet.
Most Rockford amps have a bit of voltage regulation for the rails. They quickly go to full duty cycle when driven into a load but at idle, the duty cycle of the drive signal is reduced. This will make the measured DC voltage relatively low at idle unless the DC input voltage is low.
If you have a regulated 12v power supply with a variable voltage, decrease the voltage. The gate voltage should increase as you decrease the 12v supply voltage.
If you do this, check the voltage on the gate resistors. There will be less of a chance of damage if the probes slip.
If you have a regulated 12v power supply with a variable voltage, decrease the voltage. The gate voltage should increase as you decrease the 12v supply voltage.
If you do this, check the voltage on the gate resistors. There will be less of a chance of damage if the probes slip.
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