Marshall Mode Four Repair - Part 1 - Disassembly and Diagnosis

[@HAHb-zc2dp]

My fans are loud on start up but after a minute or two theyre super quiet i probably just gotta clean en

[@RyansCustomShopandGearOutlet]

They basically are the same fans that you have in a computer. They are really easy to access and clean. I use a vacuum first to get the major dust, and then use some compressed air to get the rest. Don't let the fans spin crazy out of control when you use compressed air. I usually gently hold the fan with one finger to keep it from spinning when I am vacuuming and using compressed air.

[@Sagerydian]

@@RyansCustomShopandGearOutlet Are the fans even necessary? There's like two small preamp tubes in there - shouldn't really get hot then, I guess?

[@RyansCustomShopandGearOutlet]

@@Sagerydian The fans are absolutely necessary. While the preamp tubes generate some heat, The four TDA7293 power IC amp modules get very hot. I would say, the heat sink and fan design are actually inadequate to disipate the heat generated by the power ICs.

[@Sagerydian]

@@RyansCustomShopandGearOutlet Wow, ok. Thanks for the info. Great work, great channel!

[@RyansCustomShopandGearOutlet]

@@Sagerydian Thank you! Yes, solid state amps do get hot. Most solid state amps have huge heat sinks for the power ICs. They are usually the big alluminum "fins" sticking out of the amp. This amp has heat sinks below the fans. In one of the videos I made with this amp, I show the break down of the power IC modules, and you can see the heat sinks.