Weekend Warrior Project – Old-Skool HiFi Receiver Repair

Several years ago, Tim came across a pretty sweet stereo reciver at a tag sale. It was cheap (I belive around $10), so he bought it.

He used it for some time as a pre-amp for the stereo in his room. One day, he went to switch it off while it was playing quite loudly, and something went wrong – one of the filering caps on the powersupply arced to the case, making a huge bang, blue flash, and that was that – no more music. He attempted to troubleshoot the issue breifly, but didn’t find it worthwhile. From then on, it sat collecting dust on top of a refridgerator for a couple of years. During some renovation at his house, he decided to let it go – and that’s how it fell into my hands.

Now why would I want a broken stereo one might ask? Well, this specfific model was special – not just to me, but in-general. It’s a Nakamichi SR-3A. For anyone my age, you’re likely going “who the fuck is that brand?” – well, for those into hifis back in the 1970’s and 1980’s, Nakamichi was one of the top-of-the-line brands out there, being on par with the likes of Marantz, Krell, and others…most of those people of my age haven’t ever heard of anyways…but you get the point…and if you don’t, Google if for God’s sake!

More personally, this unit was special to me because my brother was the proud owner of a *MINT* SR-7A – one which he’d gotten for the scaresly belivable price of $120 back in 2005. Even now in 2012, a working SR-3A unit will go for north of $100 and good SR-7A can go for upwards of $300!

When my brother got his, I couldn’t belive how great it sounded, even when compared to my Marantz 2216 (an equally high-end reciver in its day!) – forget my Marantz, my brother’s SR-7A decimated my Dad’s Pioneer Eleet VSX-54TX reciver – one which when he’d bought it cost more then most people would be willing to spend on an entire home theather, let alone just the reciver – and it was getting its ass trounced by a 25 year old, $120 amp off Creigslist.

Anyhow – more on my SR-3A, and what this post is about.

So after getting this thing in my hands, it did much the same as it did in Tim’s hands – sit on a shelf collecting dust for a few years.

Fast foward to last year, and for people who know me personally will know that my brother’s old bedroom was converted into a second home theater after my familly got tired of being cold while watching stuff in the downstairs theater. Using my 42″ Samsung plasma and a random xbox 360 I had sitting around, we had ourselves a second home theater. (We stream everything over IPTV as my video server has a pair of quad tuner PCI-e cards with CableCards). It was great, but we always missed having a good sound system upstairs. My PA rig was too heavy & large to move across the hall all the time, so I needed to figure something else out.

Fast forward again to last week. I finally got around to looking at the SR-3A, hellbent on pulling together a sound system as football season was in full swing and the cold winter was fast approching. (Not like the downstairs theather worked anyways…the TV blew up quite spectacualrly in the fall of 2011, and the replacement failed out a couple of months later). Before someone comments, no – I didn’t want to bring up the audio system from downstairs as we’ve got a new TV on order…this time a 55″ Samsung plasma…no more DLP bullshit!

First I plugged the thing in to see if it’d even power up…which it did; then I threw on my EE hat and checked for the obvious shit – blown caps, disconnected wires, etc. – right off the bat, I found 2 of the 5 fuses on the powersupply were blown. After doing some testing, I confirmed these were on the output side of the PSU, and that they supplied power to the main board. After playing with settings on the unit, I established that the tuner was functioning correctly, but there was no audio output to speak of.

The next evening, Tim came over to help out since he’s got a whicked good hand for soldering (the damn fuses were soldered to the board!) – after desoldering the blown fuses, we soldered in a pair of replacements.

After doing this, we connected a pair of speakers, connected my phone to the input, plugged it, and powered it on. After not seeing sparks or magic smoke, I changed modes, and…nothing. We could hear crackling on the speakers though, so we knew we’d fixed the output issue. Tim switched the wires from my phone to a different input, toggled over to that input mode, and to our delight, music started to come from the speakers!

This amp now runs the upstairs home theater quite nicely. It’s pushing a pair of Kenwood bookshelfs. It sounds good and works great, so I won’t complain.