I wonder if this is a problem or not. I don't know enough about this to know if this is normal. Stacked parts and parts on the corner look little dark. Do u guys think these look OK?

 

I don’t see anything wrong.
Can you tell us the make and model?
What are the symptoms?

 

Anthem mca 50 5 channel home amp. The main rail caps were starting to bulge. Someone changed the main rail caps from 8200 uf 100v to 15,000 uf 80v. I had spent couple weeks trying to find the stock ones I only found 1 cap that is chemi-con 17,000 uf 80v. So since I'm recapping main rails I said let's replace all caps. I got fine gold and panasoinc upper end stuff.

 

I see no problems with the resistors themselves, but it does look like the soldered connections will benefit from being reheated and a bit of solder added. The whole circuit board looks like a cleaning is in order, that dust or whatever could hold moisture and lead to problems.
If the capacitors mentioned are power buss parts then the higher values are fine, if they are part of the amplifier circuit then an evaluation consideration is appropriate, frequency response might be affected.

 

It is main rail caps. The caps I replaced on the amp boards I used the same voltage and uf ratings. I just changed the brand and the quality of the cap to the highest I can get my hands on. I'm really new to this what would u clean the parts with? I just hope the main rail caps will he fine with 80v parts vs the stock 100v parts. I mean if this thing has to have 100v parts than it's over for this amp. Can't find them anywhere.

 

Is the actual price of the amplifier as much as an expensive car?
The specs are good but it is a shame that the power is rated at a common and horrible 10% distortion.

 

I see no problems with the resistors themselves, but it does look like the soldered connections will benefit from being reheated and a bit of solder added.

I don't see any problems either. However, as far as making the solder joints look more pretty - I'd advise against that. Thermal excursions every time you heat a solder joint leads to fracturing of the PCB and can diminish reliability. Unless a solder joint has failed - leave it alone.

In my years with IPC 610, the rule of thought was that if it is good enough don't make it better because it's Not better. It may look prettier, but it's less reliable. AND if you had to rework a solder joint 3 times then the board was scrapped. The industry I worked in was the oilfield arena. The company made both surface gear and down-hole measurement tools for off shore oil rigs. An unreliable board could potentially cause a fatal fire similar to Deep Water Horizons. Wire connections were extremely critical matters because a wire pulling out of a connector while running a pump could result in igniting explosive gasses that may be present.

If it isn't broken - don't fix it. Except the caps. If you had old caps bulging, replacing them all is wise. It's like when you replace a timing belt. While in there replace the water pump as well. Even if it's not leaking.

 

Is there any good diy kits or tips on how to clean the boards with out doing damage? I'm taking my time and ging slow using little solder i have to not over solder my joints.

 

Cleaning the board may require the use of a flux when soldering that needs to be cleaned afterwords. If you don't use a flux that has to be cleaned, leave well enough alone. You may make it look prettier, but it's not going to perform any better. So leave well enough alone.

My wife went crazy one afternoon, cleaning the microwave oven. In doing so she activated some grease and it ran down onto the PCB. When she was done cleaning it she thought she ruined it. Thought we'd have to get a new microwave. I took the board out and sprayed it with alcohol to get the grease off the board. Then to get rid of the alcohol I used water from my Reverse Osmosis filter. After rinsing the board thoroughly I used compressed air to blow dry the board. For good measure I also used her hair drier just to make sure the board was dry.

Reinstalled the board and the microwave still works fine. But that was a case where the board HAD to be cleaned. Otherwise I would have never thought to do all that work just to make a board look pretty where it would never be seen.

 

What I saw was an accumulation of dust adhering to the board, Cleaning could be as simple as using a brush and compressed air to remove the dust.
And as for "reworking a joint", no I was just saying reheat and add a small amount of solder. And if an individual lacks the understanding to do that without damage it is unfortunate. The heat application would be about 3 seconds with a properly cleaned iron. I am not suggesting unsolder and then re-install the part and resolder.

 

I am not suggesting unsolder and then re-install the part and resolder.

No, I didn't think you were suggesting that. However, the simple act of adding a little more solder means bringing a thermal mass to a cold joint that now has to heat all the way through to become a proper joint. Doing so can cause fractures within the joint substrate, which can weaken the interconnections. That's the reason why some places limit the number of times a solder joint can be reworked before the board is simply scrapped regardless of whether it's still operational or not. This is not likely to be a factor in a single or double sided board, but with boards that may have multiple layers it can become an issue. Especially with Ground planes and Power planes, which require much more heat, and often require a board to be Pre-Heated in order to get the solder to flow all the way through the joint. As for surface mount - reheating a joint applies stress to both the component and to the board. In the case of a simple resistor or cap or other similar two ended component, heating one end increases the stress on the component and pad. Heating both ends of the component bringing the solder on both ends to a molten state does not increase the stresses.

For what the TS has, through hole, and for what I see with regards acceptability to IPC-A-610 rev G (the last revision I worked with, and I've worked with all versions of the spec) those solder joints meet the standard for a class 3 joint. Sufficient solder, good wetting, no cold or disturbed joints. There's no reason to retouch those joints.

 

Evidently a much closer examinatio is in order, because they looked funny to me. Also, in products designed for longer lifetimes, the lead length is enough to protect the component. Tight bending of leads is not part of that protocol.

 

Tight bending of leads is not part of that protocol.

Tightly bent leads - a.k.a. clinched leads - is indicative of automation. Pick & Place with automatic cut and clinch. Back before SMT got going big time the P&P machine brought the assembler a bin with parts. That bin held the part for that location. If there was a blinking light it indicated pin 1. What I see in the way of solder examination is that the board likely went up a wave solder machine.

I'm not here to argue with you, nor do I get the impression you're trying to argue with me. We all see things through our own eyes and I respect your opinion. My choice to disagree with you is based on the experiences I've had with like boards and processes.

I still stand of the opinion that leaving the solder joints alone is in order. Who knows what kind of flux the TS will attempt to use; whether Flux Core solder or Water Soluble, or even No Clean. [edit] Then there's the type of solder to be used; i.e. Silver Solder or Tin Lead (60/40 or 65/35). [end edit] Soldering may likely also require cleaning. Depending on the type of flux - different cleaning methods would be necessary. Failure to properly clean the board may result in deterioration of copper traces and leads OR could lead to conductive pathways unintended which may lead to component failure. All things considered, I stand where I stand. Don't fix solder that doesn't need it.

 

I now know I have come to correct place to ask about this type of gear. I'm not a pro at this by any means. I had a guy charge me thousands of dollars and ripped me off. So I said f it and either I can do good enough job or it blows up but it still saves me money. Now I do run a automotive bussiness and did go to school for computers so I have a good understanding or good and bad ways to solder but I'm no pro. Can someone tell me why it would be so hard to find 8200 uf 100 v 35mm wide caps?

 

8200 mfd and 100 volts is not commonly used, and so it is less likely to be stocked by distributors. In that size it does not fit in smaller enclosures, either.
Those are tworeasons why a component would be a challenge to locate.

 

Few amplifiers are sold at almost $50,000 and few amplifiers use a 150V power supply (+75V and -75V) to produce deafening loudness.
They are made for audiophool billionaires.

 

8200 µF 100 V Aluminum Electrolytic Capacitors | Electronic Components Distributor DigiKey

 

Sound systems for some bands are able to provide incredible sound levels. Just go to the "Sweetwater" website and look at the amplifier listings. Of course these are not for home listening for most folks, although I did repair a 750 watts per channel amplifier for a friend,
As for the actual value and voltage rating of the filter capacitors, what is the actual voltage when the system is operating. If it is less than 75 volts then I see no need to change capacitors that have not failed. Capacitors operated with a greater margin between rated and operating voltage do typically last longer, though.

 

Electricspidey your listing doesn't have it set to 35mm wide cap or 2 wire lead with 10mm spacing. If u were to set those u wouldn't have one cap on that list. I hope these 80v caps work just fine that I'm waiting months for.

 

If you measure the DC voltage across the caps, or if it is listed on the schematic diagram, it should be apparent what the actual voltage is, relative to the 80 volt specification. What is the actual voltage is what matters.