Pioneer Amplifier Repair

Les Jones said:

It looks like either some liquid has been spilled into the amplifier or the top large electrolytic capacitor marked 38-A has leaked electrolyte (Picture 20230325_172332-jpg). This was probably the start of the sequence of events that caused the fault. You need to find a schematic for your amplifier to help diagnose all the likely components that have failed.

Les.

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Les Jones said:

Hi Nigel, If you look at the close up of the area in picture 20230325_172444-jpg you will see corosion on the cathode end of the diode and the resistors either side of it.

Les.

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Bromeliad said:

two 'exploded' HICHICON 100uF 25v capacitors

Samuel

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Bromeliad said:

Hello everyone, thank you for the existence of this forum.I decided to try to repair a Pioneer SA-540 audio amplifier ( part of an economic system from the 80s ) with almost no knowledge of the subject, but a great desire to learn.

From a careful analysis of all the components on the board I noticed two 'exploded' HICHICON 100uF 25v capacitors (brownish liquid leakage); I don't notice any other damage other than the crumbling of the thermal paste on the transistors. I was present at the moment of his death, faint sound, smell of burning and two blown fuses.

I ask you if replacing the two capacitors could be enough or if I should do other checks and if so which ones. Where can I buy spare parts? Would cannibalizing them from the matching old cassette player be an option?Vscomodapk
Which soldering iron should I buy to easily remove the solder? Thanks for your time and best regards,

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Bromeliad said:

Hello everyone, thank you for the existence of this forum.I decided to try to repair a Pioneer SA-540 audio amplifier ( part of an economic system from the 80s ) with almost no knowledge of the subject, but a great desire to learn. From a careful analysis of all the components on the board I noticed two 'exploded' HICHICON 100uF 25v capacitors (brownish liquid leakage); I don't notice any other damage other than the crumbling of the thermal paste on the transistors. I was present at the moment of his death, faint sound, smell of burning and two blown fuses. I ask you if replacing the two capacitors could be enough or if I should do other checks and if so which ones. Where can I buy spare parts? Would cannibalizing them from the matching old cassette player be an option? Which soldering iron should I buy to easily remove the solder? Thanks for your time and best regards, Samuel

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Bromeliad said:

It's great that you want to learn about audio amplifier repair! If you've spotted two damaged capacitors and some old thermal paste, start by replacing those capacitors with the same values, which you can buy from electronics stores. Cannibalizing from a similar device might work if the parts are in good condition. For soldering, a 30-40W adjustable soldering iron is suitable, along with solder, desoldering tools, and a soldering iron stand. Remember safety—unplug the amplifier and discharge any stored energy before you start. It's a learning journey, so be patient and seek help from forums or experienced folks if needed. Good luck!

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