Quote:
Originally Posted by Jon A.
I'm going mostly on other experiences I've read here. I don't think I've ever had a Trinitron with a strong CRT, apparently they don't lend themselves to rejuvenation and those SG-613 sets are so easy to blow out. Also, they use a lot of unusual parts. Good luck finding subs for anything aside from caps and resistors, especially the CRT.
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SG613s, SG608s and other Sony-unique parts
are still available - the problems most folks had with SG613 sets was their ignorance to how the circuit operated and their unwillingness to troubleshoot further. Bad SG613 with a bad damper diode? Most folks stopped at the SG613, and when it blew again, gave up. I've met several experienced techs that were like that - give them any other set and they'd fix it almost immediately, but with "SONY" staring them in the face, it's like they forgot how to troubleshoot. Never forget the basics - bring it up on a variac, check your power supplies, and then use a 100W bulb to limit the B+ until you get things settled. I never saw a flyback bad in those early sets - usually it was the SG613, a SID30-15/GH3F diode, some bad connections on the horizontal driver transformer and driver transistors (2SC1124's - odd little bastards, we ordered them 10 at a time, as the ECG and other replacements fell short...). Replace that, get those 160V electros replaced, and all was well...
Sony gave everyone the tools with the manual, but most folks used only the Sams to troubleshoot with - big mistake. Sams didn't highlight the different SG613 markings/diofferences like the Sony manuals did. The irony was that Sony (at least their California HQ) had manuals for only $5 shipped. Beautiful manuals, all pink and white...with the manual came all the service bulletins (usually 2 or 3, but some sets had 30 or more!) and any parts bulletins to update, correct or provide the latest sub for parts. I've got tons of them left over from our shop - most are dupes, as the same part in multiple Sony sets meant you got the same bulletin several times over the years.
Fix the horizontal on most, change out the dang 160V caps (Matsushita and Nichicons) and you'd have a set you'd never see as a callback.
470BEBP22 Sony CRTs did go bad, but not any more frequent than others, and a traditional brightener wouldn't do. Many developed H-K shorts, so easy isolation of the filament with a GE horizontal driver transformer (1:1.1 ratio, EP77X-something, I forget..) We replaced a few - easy peasy, as once the H-Stat was adjusted, all the dynamic convergence fell into place. Later (1980-on) Sonys had the dang pincushion magnets and the templates to use for the
starting position. Mitsubishi and even some US made sets were similar, so the pain wasn't just Sony.
I've seen only two Sonys that never left the shop - one was a 19" lightning strike write-off/gimme set, and the other was the casualty of a house fire - the back melted onto the set - a little 12 incher with the tuner under the CRT. We cut the back off, found out the extreme price (back, logo, two attachments, all coming from Japan) and shot an estimate. The insurance company said junk it, but the SET OPERATED NORMALLY! No repairs needed, it just needed a back. We relegated it to one of our "run" VCR benches for 9+ years without failure.
I will fault the Sonys with the STK regulator modules - so much simpler to follow the crowd, but what POS-es they were. Any thunderstorm ( a common occurrence here in the summer) and they'd crap an STK. We'd replace the STK, add a MOV after the fuse, and see it again for only a fuse replacement. Add to this the IF soldering issues (easy, but from the factory in Mexico problem - should have fixed it there...) and you had a steady stream of sets coming in. Our last few years were the dang MX0841 sets - either them or the 2SC4927's - again, mostly lightning strikes, and after the Sony 04-2mod, never a problem again.
We made more money off GE, Zenith(name the problem, we saw it...), and cheapo Sears (bad flys in the Sanyo sets, bad vertical and caps in the Toshiba sets)/Wards(Admiral woes - mostly horiz outputs, and electronic tuning issues)/AOC/Bohsei/Emerson(Caps, chips, and vertical issues)Sanyo/Sharp(Flybacks - mantra was "RTRNF00-what??") and MGA sets (PIP modules, lots of sound issues, etc). Sonys were fewer in the mix, but still there....