waigy
Senior Member
Last Activity: 11-12-2024, 05:57 AM
Joined: 11-19-2009
Location: Fife
-
Variable resistor potentiometer has different reading when mounted on the board
In my fusion FE-402 car amplifier the gain pot is an RK097G.
I think it is anyway, the RK097G is the closest I've found to the original with the same pin number and dimensions.
The differences are my pot is blue and has B203 on it and the shaft is plastic with a small slot at the very end only.
I measured the resistance and found it went from 0 up to 10k so I ordered a 10k pot.
I then took the pot out the board and it now measured 22k.
I tried putting it back in the board and it goes back to 10k.
Is this normal and if so what pot should I order?
On this... -
I tried the 100k pot and it still did the exact same thing making the speakers pulse slowly in and out and crackling etc., that was before even starting to turn the pot up, so it will be something else I have damaged on the board by taking it in and out a few times.
I had a couple of schoolboy errors when refitting the large heatsinks and saw sparks twice so that might have blown something else.
I just got myself another amp to add to the two I got last night (one of which was dead on arrival).
So I currently own 5 amps, with 2 not working, but the amps that are working are much...Leave a comment:
-
I found out the cause of all the crazy stuff the amp was doing.
After checking the resistance of the pot, but just before soldering it back into the board, I used pliers to make sure the metal tabs that hold the pot together were bent firmly back into position.
When I did that, I put a fine crack in the back plate of the pot.
I just checked the resistance again and it was going up to 200 then getting no reading.
Because I bought two car amps last night for £20, I'm past the point of considering this junk now so I just put one of the 100k pots for adjusting the high pass...Leave a comment:
-
One step forward two steps back.
I excitedly built it all back up, connected the speaker wires etc. into the car then drove about a mile to the nearest place I can turn up the volume without people hearing and it's much worse.
There's now something very wrong with the rear gain pot.
Just before soldering it back onto the board I measured the resistance and it was still working smoothly from zero up to 20.
But now, even with the rear rca inputs disconnected, if I turn the rear gain pot a tiny bit, the rear speakers crackle and start to move in and out.
With the rear...Leave a comment:
-
I have now put the pot back together (the correct way round) and it is measuring from zero very smoothly up to 20.
I will put it back in the car soon and let you know what happens.Leave a comment:
-
I did that and got very weird results.
I also noticed the pot is upside down.
UPDATE AFTER WRITING A LONG POST HERE
I didn't think it was possible to fit the pot upside down, but realised I had rotated the middle part of the barrel when I took the back off.
Putting it back on now....Leave a comment:
-
UPDATE: I just spent the last 2 hours taking the amp out the car, taking it apart, taking the rear gain pot off, taking that apart and cleaning it with contact cleaner then putting it back in the car and testing it.
Cleaning the pot hasn't fixed it.
I've been doing tests with both rear speakers connected and the balance in the middle but I tried with each side connected one at a time
There has been times where both speakers distorted, but once I was able to crank the left rear speaker up very loud before distortion to the level it should be at.
With the right rear only...Leave a comment:
-
It makes me feel good that I now have a clarion amp and not a cheap maplins amp like I always thought I had, so I will be able to impress the ladies now.Leave a comment:
-
Redwire, you mentioned "Not sure if something is heating up to make it take a while to distort".
When I mentioned the amp starting to distort quickly, I was talking about the initial set up when adding new speakers.
You have to turn the gain pot up until the speaker starts to distort then turn it down a bit.
But, with the rear speaker output, the speakers start to distort after turning the pot just a small amount when the speakers are still quiet.
The speakers actually have no distortion if you keep the gain pot at its lowest setting, but the speakers are very...Leave a comment:
-
That's a brilliant find, well done.
It's great having the service manual and schematics, but I'm not an expert electrician so I can only suss out very basic parts of schematics.
I only have a soldering iron and multimeter and I also don't know how to do some of the things you are suggesting unless you tell me exactly how to do it in laymans terms.
I appreciate all the help and have always been grateful for the badcaps forums in the few times I've had a fault like this.
It's great that the service manual has a list of the exact capacitors and how many of each are needed....Leave a comment:
-
I thought I could use all the images I took to get details of all the capacitors so I put the amp back in my car but, some that are the same physical size have different u numbers or voltage, so I'll take it out again tomorrow and take a note of exactly what I need.Leave a comment:
-
I'm going to recap the board at least.
Can somone recommend the best replacement capacitors to get?
The cpc farnell site has lots of different makes and types for the 2200uf 35v capacitor.
They have 6 different panasonic 2200uf 35v capacitors.Leave a comment:
-
These are close ups of the different capacitors and an image of the top of the amp....
Leave a comment:
-
I don't have an oscilloscope, only a half decent soldering iron.
I have recapped boards before but they were like this one with large components.
I don't know how to check voltage rail specs, could you tell me how to do that?
I have a multimeter.
That's the wrong amp you sent a link for.
It's nikkai....Leave a comment:
-
Nikkai EAPA 450 car amplifier rear speaker output is a low level and distorts easily
As the title.
I think these used to be sold in maplins a lot of years ago, it is an antique, but it's just fine for my needs.
It looks basic enough inside with large components so I could do a full recap pretty easily.
Any suggestions on what component would cause the symptoms of low volume output on both left and right rear speaker outputs?
If I turn up the rear gain level in the amp until the speakers start to distort it starts to distort quickly even though the speakers are still pretty quiet.
I thought I had dodgy speakers as I just fitted new old stock 6x9s in... -
Re: HDD stops after about 2 minutes
I tried a fan and it's just the same.
I've only recently looked at the smart info and it shows as "Caution reallocated sector count" (image attached) which after a quick google search is supposed to be unfixable.
I think I should take the drive to my nearest river and give it a float test to determine if it floats or not.
I've heard seagate drives are notorious for sinking in water....Last edited by waigy; 11-11-2023, 02:02 AM.Leave a comment:
-
Re: HDD stops after about 2 minutes
Update:
I got a replacement hard drive motherboard (used but working from Aliexpress) and successfully swapped the firmware chip from my bad drive to the new board as my pc recognised it straight away and I could access the files but, I
was back to square one with the drive stopping after 2 minutes.
So the board is very likely not the fault.
I also got a usb 3 docking station which allowed me to copy files from my dodgy drive for 2 minutes then I could switch the docking station off then on and it would carry on...Leave a comment:
-
Re: HDD stops after about 2 minutes
I've tried a different sata cable into a different port on the motherboard, it does the same thing.
I've already cleaned the connections on the back of the hard drive board with contact cleaner and cotton buds.
In the past hour I've managed a workaround.
Before I had to wait for the pc to boot into windows (about 1 minute 30 seconds) then I had about 10 or 20 seconds to access the drive.
But I now have the drive sitting outside my pc case and I can easily pull the power connector out of the drive then plug it back in again....Leave a comment:
-
Re: HDD stops after about 2 minutes
I had a look at the board with a magnifying loupe and this mosfet looks like it's a bit burned.
TR1 9
Would that cause the symptoms I am having?
The drive stops being accessible after about 2 minutes?
I forgot to mention in my first post that the drive carries on spinning after it stops being accessible or found on the system....Last edited by waigy; 10-28-2023, 10:16 AM.Leave a comment:
No activity results to display
Leave a comment: