I messed up...

Video Description

Last year I dove back in to working on vintage stereos after a 10 year hiatus and my first big project was restoring a Pioneer SX 434 for a friend along with some speakers. Finished the restoration and delivered the system but a couple of months later the phono stage stopped working properly. Fast forward to December 2023 and I made the few hour drive to my friend's house with parts and soldering tools in hand. I updated the phono stage and it worked great. Unfortunately, I decided to test the receiver with the heatsink removed from the output transistors and it caused major issues. I had to bring it home and am now diagnosing it and hopefully fixing it for the last time. I'm a bit embarrassed that this happened. I'm still learning and am by no means an expert which is why I tend to work on stuff for my friends instead of for other people. I've also come a long ways since I first restored the receiver last year and leaving the heatsink off was one of those you'll-only-do-it-once mistakes. Timeline: 00:00 Intro and explanation of the failure 01:44 The current issues 02:29 Troubleshooting 05:25 Rant about old Service manuals and parts labeling 07:11 Troubleshooting Cont. 08:21 Sneak peak at future projects 08:46 Checking for bad components in the pre amp 10:21 Installing new parts 11:08 Finding the correct output transistor replacements 13:13 First test on the dim bulb 13:40 Checking voltages and reassembly 14:16 Full test •••••••••••••••••••••••••••••••••••••••••••••••••••••••• Hey! My name is Matt and I sure do love stereos! I got into this hobby when I was in high school over a decade ago. I had huuuge speakers in my bedroom and way too many pieces of gear (my mom was worried I would become a hoarder haha). I started repairing stereos for friends a few years back and decided to make videos about it! Now I repair gear for people. If you want to send yours in for repair, head to my repair form: https://forms.gle/Tk5xAEkGgVdyZ4w4A Some of my favorite brands are Yamaha (CRxx20 series receivers, CA 1010/2010 integrated amps), Harman Kardon (Twin power receivers 430, 630, 730, 930), and Sansui (X0X0 series receivers, AU 717, 919 integrated amps). Test equipment: (I earn a small commission if you buy from these links) -Dim bulb tester! I made mine but you can find them on various websites -Soldering iron Hakko FX 888 https://amzn.to/3JhyNrK -Hakko FR 301 solder sucker https://amzn.to/4ogUecy -Main Multimeter (Fluke 87V) https://amzn.to/45dvqJS -Get the mini grabber leads for it! https://amzn.to/4qpJzxt -Cheaper multimeter (Fluke 115) https://amzn.to/4o9y0ce -Oscilloscope Siglent SDS 1104X-E https://amzn.to/43ovYMU -Function generator Siglent SDG 1032X (There are newer versions out so finding this used online is the best option) -Capacitor tester Peak Atlas ESR 70 https://amzn.to/3JjBauK (The price here fluctuates, you can usually find them cheaper on other stores) -Transistor tester Peak Atlas DCA 75 (you can get the cheaper 55 model but it’s not as good so if you can afford it this is the one) https://amzn.to/4oaW6TS -Hagerman labs IRIAA (Phone or signal generator gets dropped to phono cartridge level) https://hagerman-audio-labs.myshopify.com/products/iriaa2-inverse-riaa-filter Tools: -Ratcheting screwdriver https://amzn.to/3WihZED -Needle Nose pliers https://amzn.to/477nQmr -Lead forming pliers https://amzn.to/3JsB1oK -Capacitor drain tool https://amzn.to/4oD6HGZ -Wire strippers https://amzn.to/43r26iU -Magnetic Helping Hands https://amzn.to/4o5BAnF -Plastic Rocket Sockets https://lovemyswitches.com/rocket-sockets-pedal-building-socket-set/ -Fiber glass pencil for cleaning metal contacts https://amzn.to/3Jdn0eG -Digital caliper (Don’t cheap out on one like I did, this one is nice) https://amzn.to/3WS5cJ7 Chemicals/glues: -Electronics contact cleaner https://amzn.to/4o7yH5O -Deoxit D100L for metal contacts https://amzn.to/3WRiXaS -Deoxit F100L for graphite contacts https://amzn.to/4hps1xf -Solder flux in a syringe https://amzn.to/4hpNs1f -Dow Corning 340 Thermal paste (Non conductive) https://amzn.to/4o6f65O -Freeze spray (Electronics safe) for finding faulty transistors https://amzn.to/4qlDvGl -Silicone oil for cueing cylinder on turntables https://amzn.to/43osOsw -Acrylic glue for dustcovers and such https://amzn.to/4o87TSZ -Mother’s Mag & Aluminum polish for faceplates https://amzn.to/3L70ip2 -Meguiars ScratchX For light buffing https://amzn.to/4ht58t1 Miscellaneous useful items: -Tuner string https://amzn.to/3Wl6DzK -Parts organizer bins https://amzn.to/4ht3nfp PCB Repair: Eyelets https://amzn.to/4qr8TTH Punches for installing eyelets https://amzn.to/48LJbmE Hand drill for enlarging PCB holes https://amzn.to/3WoxWZQ Instagram: @Shuksanaudio Tik Tok: @Thedealydeal eBay: https://www.ebay.com/usr/shuksan-audio