Sanyo DS31590 31" TV from 2002 - Videokarma.org TV - Video

radiotvnut · #1 07-11-2015, 05:18 PM

Every time I say that I'm not taking in any more BPC/SPC CRT TV's, someone offers me one and I end up taking it. This one is a clean looking, but dead, 31" Sanyo from 2002, with the instruction book and original remote. From the lack of dirt inside, it looks to be a fairly low hours TV.

I quickly found the problem to be a shorted HOT (2SD2645) and this was causing the power supply to go into over-current shutdown.

Usually, when a HOT shorts, it had help; but, they sometimes blow on their own. The most common causes for HOT failure is a defective flyback (the one in my set passes the ring test), bad electrolytic capacitors in the horizontal drive circuit and B+ line (all capacitors checked OK), and bad solder connections that cause a rapid dropout of horizontal drive (a few connections looked slightly questionable; so, I resoldered them). Another thing that can cause a shorted HOT is a switching power supply that's running away with itself. I've seen these power supplies lose regulation and shoot hundreds of volts down lines that should only have 5V-12V on them. When this happens, the damage is usually extensive and the set isn't worth repairing. I measured the B+ voltage in this set and it seems to be fine.

At this point, all I know to do is install another HOT and see what happens.

As far as later model "bargain" TV's, Sanyo seems to be one of the better brands. If I fix this, I'll probably give it to a friend who needs a TV (if she'll take it). I hope she'll take it because if not, it will go up for sale and then I'll get ticked off when, 3 weeks later, I still can't $35-$40 for the set.

Currently, I'm trying to get $25 for a 2002 Sony 20" WEGA Trinitron and the only one who has commented was someone offering me $20 if it had the remote. Well, no, it does not have the remote and for the price I'm asking, they can go to the dollar store and buy their own remote. I'd certainly take $20 for it; but, they're not getting a remote that I never had to begine with.

I've also got a working 27" RCA from 2000; but, the CRT is tired in it. It would make someone an OK TV, if they didn't have anything and didn't have much money. However, I'm not even going to bother listing it for sale.

Actually, the Sony and RCA will probably be given to my friend who runs a flea market and maybe he can make something off of them.

zeno · #2 07-11-2015, 06:06 PM

Gotta agree of the low end Jap & ROK sets Sanyos seemed
to be the best over the years. From 13" up these simple
sets never asked for much time on the bench & came out
good, sometimes better than high end sets. Only beef I have
had was the disco of parts such as vert modules & power supply
modules for the Fishers.
Also going back to the 80's one summer we had at least 25 Sanyos
& Sears sets waiting for Z0064 rectifier/dividers. Took a few months
but they came through eventually. Even then they were decent sets
even with the Sylvania tubes that loved to short.
Good luck selling it, I would rather have that than most new stuff.

73 Zeno

rcaman · #3 07-21-2015, 09:53 PM

i always like fixing the sanyos always easy fixes the sets held up great.

Findm-Keepm · #4 07-22-2015, 05:05 AM

Quote:

Originally Posted by zeno

Also going back to the 80's one summer we had at least 25 Sanyos
& Sears sets waiting for Z0064 rectifier/dividers. Took a few months
but they came through eventually. Even then they were decent sets
even with the Sylvania tubes that loved to short.
Good luck selling it, I would rather have that than most new stuff.

73 Zeno

I remember those Sanyo/Sears sets with the funky focus dividers - mounted on a bracket with a couple of screws.

I loved the old metal cabinet Sanyos - 91C90s and their brothers. They rebadged them for Channel Master and TG&Y, maybe others. My first boss had a Channel Master-badged Sanyo.

As to the newer stuff like Bryan's set, Horiz outputs, LA7838's and a few diodes in the derived supplies were about all I can remember replacing. Great sets for the money.

Cheers,

radiotvnut · #5 07-22-2015, 10:03 AM

I remember some '80's Sanyo-built sets that used an oddball TO3 cased HOT where, IIRC, the emitter and collector terminals were reversed. Then, there were those vertical modules that contained surface mounted parts on a ceramic substrate and these would develop loose connections.

Zenith26kc20 · #6 07-22-2015, 12:16 PM

Most of the time we found the horizontal output transistor failed when the flyback punctured. Putting a new HOT would bring the HV up for a moment then a crack and a spark and another shorted HOT.

radiotvnut · #7 08-27-2015, 10:37 PM

Well, I got it working by replacing the HOT and resoldering some questionable connections. I also replaced the 220uf cap in the vertical circuit that likes to fail, causing lines and vertical IC failure. The set ran for several hours with no issues; so, I put it back together and will be giving it to a friend who needs a TV for the livingroom. In the back of the vehicle at this moment, there is a 27" RCA CTC203 set from 2000, a 13" Orion from 2000, and a 20" Sony Wega from 2002 that will be freebies for the flea market. I made one last effort to try to sell them; but, didn't get squat for interest; and, frankly, I'm tired of them being in my way. So, they our out of here tomorrow and I'm going to try not to take in any more BPC/SPC-era TV's. Had it not been for my friend needing a TV, I probably would not have even bothered with this Sanyo. It's funny that 15-20 years ago, I was replacing flyback transformers in knob-tuned 13" TV's and actually making money off of them. Now, I wouldn't replace the flyback in a 36" set, if my motive was to make money off of the deal.