Sony Trinitron TV teardown (1979) - Page 1
Forum section: electronics / general

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 03, 2014, 10:50:33 pm
content: SO VINTAGERelated to my teardown of theSony Trinitron computer monitorActually use a tripod in this one!Kind of cool. Interesting to see the way they did things back then compared to how I've seen them done in TVs now (by now I mean early 2000s)I like how they do the illuminated channel selector with the neon bulbs.As mentioned in the description, I was disappointed that I couldn't find a service manual, but it was still fun.Thanks for watching!

author: mariush
author_rank: Super Contributor
timestamp: January 04, 2014, 12:59:00 am
content: @17:50 those boxes with dots in them may be just a sort of revision number system for the board. The black rectangle by the leds (sip package) may be just a resistor network.@30:00 cd, cu .. maybe channel down , channel up , mute ... could be infrared and this board being reused on other television sets.@38:00 and some place earlier BKG would mean background to me but not sure that's the meaning.. a few minutes before AGC could be automatic gain control :http://en.wikipedia.org/wiki/Automatic_gain_control#38:45 that's to-3 not to-220Overall interesting and good job using that makeshift tripod.Found it interesting that they still designed electronics in such a way as to require hand soldering wires around the board surface instead of optimizing things so that they could just use connectors. I guess workers were cheap.Saw some flux residue in some spots, making me think they hand fixed some components.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 04, 2014, 03:44:18 am
content: Really appreciate the answers cant wait to read up in agc, though its presence makes sense as radios have it as well. Appreciate the feedback on video quality as well, im wirking on it and it seems to be getting better. The makeshift tripod is working out pretty well.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 04, 2014, 06:55:11 pm
content: Sorry for the lack of punctuation and spelling mistakes, I did that up on my phone.

author: MartinX
author_rank: Regular Contributor
timestamp: January 05, 2014, 11:16:03 pm
content: YUCK! I remember those from the late eighties when I worked in a TV repair shop and we had a flood of them coming in, a large hotel in town had one in every room and the precisely engineered lifetime must have expired, it was a special hotel version with a lock on the lid over the channel setting buttons and a short piece of chain attached to the rear so you could anchor it to a table or something.The schematic was on a single small piece of paper and it did not match the actual circuit very well, they had a funny failure mode, the high voltage became to high so the picture shrunk and it started to emit a lot of very disturbing crackling and popping noises, the hotel guests must have been surprised. The transistors were all Japanese and a bit hard to get hold of then, possibly even harder now.I don´t remember the details now but the TV in your video seems a bit more modern than I recall, maybe the sets I worked on were a bit older than yours, there would also be a slightly different version in Europe.

author: Unknown
author_rank: Unknown
timestamp: January 05, 2014, 11:18:34 pm
content: Quote from: MartinX on January 05, 2014, 11:16:03 pmI had to read that a couple of times trying to work out why all the hotel guests were experts on Far Eastern electronic component availability.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 05, 2014, 11:43:20 pm
content: Quote from: MartinX on January 05, 2014, 11:16:03 pmCool story! That IS a pretty weird failure mode, the high voltage would accelerate the electrons faster leaving less time for the magnetic field to deflect them, eh?And yes that sentence was rather odd, still loved it though haha.Thanks for the replies!

author: MartinX
author_rank: Regular Contributor
timestamp: January 06, 2014, 12:02:37 am
content: I completed the punctuation in my post, the quotes will remain odd.

author: Stonent
author_rank: Super Contributor
timestamp: January 06, 2014, 12:35:09 am
content: One of my Aunts had a TV that each station had to be manually set. There was a strip similar to yours, but there was a pot near each channel that you had to adjust to get it just right. I remember it wasn't set right so a lot of the stations didn't match, but it worked.

author: Unknown
author_rank: Unknown
timestamp: January 06, 2014, 12:37:55 am
content: Quote from: Stonent on January 06, 2014, 12:35:09 amDunno how old you are but when I were a lad that basically describes all of the TV's on the market.

author: Stonent
author_rank: Super Contributor
timestamp: January 06, 2014, 12:41:58 am
content: That one, I'm not sure it isn't an inductor because it says 30H at the top and also 8.2(Omega)K so I think 8.2k not 8.2 Ohms.

author: Stonent
author_rank: Super Contributor
timestamp: January 06, 2014, 12:46:03 am
content: Quote from: Lurch on January 06, 2014, 12:37:55 amLuxury! When I were a young man, we'd tune the TV using an old coat hanger. Dad would have us hold the antenna beat us with a coat hanger until we had contorted with pain in a way that tuned the station correctly!Ay! But we were happier back then, even though we were poor.:DDI'm in my 30's.

author: Stonent
author_rank: Super Contributor
timestamp: January 06, 2014, 01:31:15 am
content: It was fairly normal on older TVs to run antenna stuff over 2 wires like that. Some had 4 screw terminals and some had 2 with one coax. It seemed to me that the UHF usually was on the spade terminals and the VHF was on coax.The BKG part is blanking that's the period between frames.The G and B were probably Grid (or Grille) and Base. Trinitron tubes used fine wires stretched across the front of the tube that sort of masked the electron beam to be more sharper. Non-Aperture Grille screens used what was called a shadow mask, a much smaller grid at the neck of the tube. That wasn't as sharp of a picture as a Aperture Grille screen since the beams could distort after they left the shadow mask.Another fun bit of trivia on aperture grille screens is you will see anywhere from 1 to 4 faint lines going from left to right on the screen. Those are stability wires to keep the fine wires from moving much. You can usually thump the side of a aperture grille TV and it will shimmer for a brief moment. Numerous times I've seen people try to return Sony TVs or monitors because they said "there's a line in the screen" and if you tried to explain it to them they'll just fixate on it and refuse to accept it.

author: vk6zgo
author_rank: Super Contributor
timestamp: January 06, 2014, 01:52:47 am
content: Quote from: mariush on January 04, 2014, 12:59:00 amBKG stands for "blanking",AGC is definitely "automatic gain control"Sonydiduse a fair number of connectors,but didn't get caught up in the "edge connector" craze---their reliability was much better as a result.Philips virtually killed their market in Oz due to the unreliability of the K9 & related models,where they used cruddy sub-boards plugging into either the main board or chassis mounting sockets.A lot of people don't like Sony,but I always found they were better designed than their competitors,with the sole exception of their SMPS .Reliable enough--- but why use 10 different designs?--Sanyo kept the same basic design for 20 years!

author: vk6zgo
author_rank: Super Contributor
timestamp: January 06, 2014, 02:01:54 am
content: Quote from: sonnytiger on January 05, 2014, 11:43:20 pmIn a lot of Sony sets you could replace the Japanese transistors with whatever Philips used in similar sections of theirs.In the big Sony 27" "Profeel " monitors,you could use BU208Ds in both the horizontal output & the SMPS.Not the ordinary BU208s,only the "D" variant,which worked better than the original Sony device in both positions.

author: mariush
author_rank: Super Contributor
timestamp: January 06, 2014, 02:07:00 am
content: You don't have to tell me about Phillips.My parents bought a Royal (basically Phillips designed licensed to a factory in Romania or somewhere close) and the tv failed 3 or 4 times in a year.The TV looked very similar to this tv (if it's not actually the same model) :http://mercador.ro/oferta/vand-televizor-color-royal-ID10ZDL.html#92b5fb68f4The failure was always a DIP chip that was maybe 1 cm from a very hot heatsink. If I remember correctly the IC was used to make the image black while switching channels, so when it was dead there was only one thin white line in the middle of the screen, or nothing at all.Back then I wasn't so curious about electronics, so that's all I remember the service guy telling my parents.The other failure was that the buttons on the front panel were basically about one centimeter away from the actual board with the internal buttons and the plastic holding the buttons broke.The channel up , channel down buttons on the tv fell inside the tv so I could only change channels using the remove or by inserting a screwdriver to hit the standard push buttons on the main board. Looks like the TV in the link above will have the same problem soon (ch up / ch dn buttons are slightly depressed, sign of weaker plastic)

author: MartinX
author_rank: Regular Contributor
timestamp: January 06, 2014, 02:11:08 pm
content: Ahh! Philips K9 and K11 the breadwinner for so many TV repairmen, they were fairly easy to repair and the service documentation was quite good, you could repair the modules yourself instead of buying a new expensive one from Philips, then they had a later model that had some novelty ceramic modules on the CRT board that also failed quite often.I never liked Sony TVs, the service documentation was minimal and they often used thyristor horizontal output stages something they probably copied from some German manufacturer as they were the first to use that. It was often difficult to access things due to the convoluted layout with wires criss crossing the whole thing, during the time it took to repair one Sony TV you could have repaired four Philips instead.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 06, 2014, 04:59:37 pm
content: Lots of great stories guys, appreciate the read!

author: SeanB
author_rank: Super Contributor
timestamp: January 07, 2014, 07:22:27 am
content: I remember the one TV spares place ( still is open, and still does business) which had a whole range of kits for Sony sets, from GCS switch replacements ( often a whole bag of resistors, a pcb, a BU508D, a few diodes and capacitors along with some precut wire and a sheet of paper), tuner replacements and assorted control board replacements. There probably are still a few hundred sets dating from the early 1980's and the late 1970's still running around here, probably with the original Sony tubes as well.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: January 07, 2014, 12:20:10 pm
content: Cool, I am suprised mine is still running on original hardware considering the environment it was operating in and the how dirty it was. It was also out in an unheated garage for who know's how long.