I'm very impressed. I've been trying to recap Aiwa's (pc202's) yet after, I get lots of distortion, possibly since i'm not doing a good job of cleaning. All I've been doing for cleaning is scrubing the PCB with baking soda and water then drying it with a blow drier. Would you kindly share as to how you cleaned up the pcb & your overall repair methodology? Kind regards, Command8
Hi, @Command8 All replacement parts are from Mouser. I have a Weller temperature-controlled soldering station; I use a combination of braided wick and pump to remove SMDs, depending on size. I never use the pump on the actual part, more like to remove excess solder before tackling the actual part I want to remove. I think my success is mostly due to not rushing anything . I really want to have an end result I can be proud of. So, no rush. To clean the PCB, I use warm water, a pinch of soap and a soft toothbrush. I am careful what areas I clean. If there are coils, relays or other sensitive electronic components, I place blue painters tape on them. I never soak the PCB in water, just a bit of carefully controlled running water on top of it. I shake to dry then I pat with a paper towel. For rusted or corroded areas I use my Dremel with a nylon or metal wire brush. The power connector on this PCB (see reverse side picture, by the motor stabiliser IC Texas Instruments TPIC 326A) was seriously corroded, so I used the smallest wire brush on my Dremel at very low speed. Once it's dry, I take cue-tips and soak them in 99% isopropyl alcohol and clean the rest of the flux/dirt deposit. Then another warm bath as needed. After I solder the replacement components, I again use a cue-tip with alcohol and remove the flux from around the new joints. I am not familiar with Aiwa's HS-PC202. Distortion can be due to a wide range of issues; check your voltage delivery to the amplifier (preferably with an oscilloscope) and ensure the components in the signal path are within tolerances. If you can find the chip manufacturer's AN (application note) that shows an example schematic, you can see where your probable cause is, and also what the correct values should be. I hope this helps. Virgil
