Laney IronHeart amp

[Mars Amp Repair]

Hello folks,
Just for information: This amp came in with symptom of 'Rhythm Channel intermittently looses gain'.
Turns out the white connectors between the Rhythm channel and the main board are secured with a black Loctite type paint. It was applied sloppily and travelled down thru the holes where the wires go into the plugs and coated the pins in the connector.
It also did the same for the ribbon cables that goes between the rhythm channel & main board as well as the one that goes between the main board & the power tube board.
I was going to just eliminate the plugs, until I realized that ALL the connectors had this issue.
Remove the plugs & burnish the pins where the black paint coated the pins. I used a mini round file to accomplish this. It serves to clean the paint off of the pin as well as acting as a file when plugged back in to remove the paint in female connector in the plug.
I also found all the slide switches on the rear panel were very dirty. Deox took care of that.
So, there were multiple issues that caused the sound to become intermittent for all the modes of the amp.
Hope that helps anyone.
The pix show the connectors I bypassed, before I realized ALL of them had the same issue.
Glen

[Greg Robinson]

Those look to be JST (Japan Solderless Terminals) XH series connectors. Available in the US from Digikey and Newark I believe. I keep them stocked, as I use them in my own designs and also find them in a lot of products. I probably would've just replaced them rather than trying to clean - especially with anything abrasive like a file which removes plating and leaves things more likely to tarnish in future.

[Mars Amp Repair]

Those look to be JST (Japan Solderless Terminals) XH series connectors. Available in the US from Digikey and Newark I believe. I keep them stocked, as I use them in my own designs and also find them in a lot of products. I probably would've just replaced them rather than trying to clean - especially with anything abrasive like a file which removes plating and leaves things more likely to tarnish in future.

Good point Greg for some applications, .
I've treated these connectors in this manner for years on consumer devices since the 80's with no issues. It's rare that it is even needed at all, unless there is corrosion, as the more common issue is usually with the crimp connections to the wires.
I don't believe there is any coating on these consumer grade connectors as this is not a gold plated aerospace application going on here (;- ).
If I were to replace all of the 2 pin connectors and the 4 multi-wire ribbon connector sockets, that would have been a total of 12 connectors. With removing all the circuit boards to access the underside, that would have added about 4 hours to the repair, which would have been very uneconomical for this item and possibly ended up with the amp as a good-solid doorstop in front of a heavy door.
The contacts that I absolutely will not burnish are known coated devices eg: speaker relays or any relays for that matter, as I know for sure they have coatings like nickel and they absolutely will fail again.
I really don't mean that to be adversarial, it's just the only practical way to deal with lower priced items. From experience, I know that I will not see this amp back with any further problems from this repair.
Thanx, glen