Sony KV1810ub technical info

[gezza123]

HI'Guy's I don't know if anyone repairs sony TV anymore,I found this document that may be of use to somebody.
Its a modification kit for KV1810UB to stop the set blowing its G.C.S and protect the set.once we change it we never seen the set again.Gezza

[Andy Doz]

Oh that brings back horrible memories ....

[gec2110]

I really hated these sets there was one engineer who used to struggle with them and spend hours upon hours checking changing soak testing to be rewarded if he was unlucky
by blown up devices after 2 or 3 days
the GSC devices were very expensive indeed

[Welsh Anorak]

Hi
As far as I know the modification was just a crowbar thyristor circuit that blew the fuse instead of the GCS, like the original TX9 chassis.
Trouble was it stopped the set from working and didn't solve the original problem which could be due to (in our experience) almost anything! ITR 'Television' did a comprehensive 'what to do' article involving bulbs and variacs, but even then it was best to emigrate once you'd returned one to the customer.
Even nostalgia hasn't made the 1810 seem a good proposition.
Glyn

[Andy Doz]

1820 on the other hand ....

[Welsh Anorak]

Hi
Ah yes - the 1820 rarely went wrong. Great sets - almost made up for the 1810. Almost.
Glyn

[chroma04]

Hi,

I have the February 1987 issue of 'Television' magazine which details the conversion of the 1810UB from GCS to transistor. Whether this made the sets any more reliable in the field is anyone's guess....


Adrian.

[Jason Pero]

Pfft.. I wonder what can cause failures of this to cause GCS to blow up? The circuit is very head-scratcher design. Compared to this simpler CTC203 SMPS, I'd prefer that.

Ah, what made the intermittent no-power up on KV-2064 series, resoldered everything, checked capacitors etc. Yet, you have to heat or try several try then TV finally power up
And on other end, some would start and going then TV simply stops. No drama. Thanks for so mysterious problems with sony designs.

Cheers, Wizard

[Welsh Anorak]

Hi
I remember the magazine conversion from GCS, and I think I did try it out once out of interest. However, I wouldn't have done anything like that for a customer's set - besides which by 1987 the sets were a (bad) memory for most engineers.
I suspect Sony were so thrilled with their GCS devices that they wanted to show how reliable they were. And, to be fair, they probably were as a spike lower down, or a line oscillator fault was the reason for their demise, not the device itself. But as Wizard says, the circuitry wasn't particularly easy to follow, particularly considering Sony's convoluted way of drawing diagrams, and Sony didn't help by charging a small fortune for the replacement parts.
Glyn

[DangerMan]

Hi all
yes, the bad memories come flooding back. [shudder]
SG608, SG613 and their replacement, SG6533. And then the SG264 that was used in some sets as the E-W modulator, and which used to go open circuit all of its own accord.
These 264's were actually much cheaper, and could be used quite successfully in 1810's (especially nasty ones which kept eating them) but I remember a service bulletin from Sony which basically said "Stop it"! They must have been losing a fair bit of revenue, especially as we also used them in KV1820's !
The big snag with the GCS's was that they required continuous drive pulses, as once they're on, they stay on until gated off.
So if your line oscillator missed a beat (and it also triggered the smps) you'd end up with both chopper and line output devices turned on across the rectified mains... until the oscillator and rest of the gubbins woke up and turned them both back off, which was never in time.
Worst of all, the original overvoltage trip deliberately removed the trigger pulses, almost guaranteeing that both GCS's would go short if the HT went up.
To cap it all off, there was a batch of dodgy thermisters, used in the smps control loop, which caused exactly that to happen.

Drrrinkk!! Nurse!! :-(

TTFN
Pete

[Welsh Anorak]

Hi
Ah yes - the Sony thermistor - that does waken a memory. Of course by the time it was known many GCSs had been eaten. Luckily the SG264 didn't cause any other problems when it died in a E/W circuit - and it was cheap. In fact I think Sony were often "out of stock" of the 264s but had plenty of the 613s in. Wonder why?
ISTR Sony came up with all sorts of technical reasons why only the original or their supplied replacement GCSs could be used in the 1810. Wonder if they ever saw the proposed BU28 mod??
In the early Eighties a colleague of mine set fire to his 1810 manual and vowed he would never have a set in his workshop again.
Glyn

[CapitainePlumo]

Hi.

KV1810UB can be tamed if you have time, dedication and patience. What you really need to do is replace ALL electrolytics in the power supply. Check and replace all important electrolytics on the scan circuits too, especially the 22uF on the frame output if you don't like to see reduced/distorted height, flyback lines or frame collapse. Resolder the scan/EHT board on the right hand side which often suffers from corrosion between the copper pads and the soldering, thus making it accident prone.

I have successfully used a transistor instead of a GCS. Tried many and only one did the trick, the R2010 transistor initially made for radar systems by Texas Instruments and adopted by Thorn for their 3000 Chassis as a chopper in the power supply. However you will need to adapt it on a small heatsink as it is larger than a GCS. Finding a GCS these days is probably very difficult unless you are very lucky. Finding an R2010 should be easier and can be a direct replacement without any mods except the heatsink.

Failing this on a few occasion I fitted damaged or butchered KV1810s with a modified or home made Switch mode power supply (there are countless choices these days). All you need is a 135 Volts output and a temporary 18 Volts kick to the line timebase chip. That chip later gets its own 18 Volts from the line transformer after the line starts running.

From my experience these sets are great and early ones are fitted with excellent tubes; I still have one here.

Reards and good luck from Captain Plumo

[Welsh Anorak]

Hi
Ah - thought there might be someone who liked the 1810! Interesting the R2010 will fit with no electrical mods considering it's quite a different animal.
It was a pity about the design as they were nice and compact and comparing the performance with, say, a Thorn 8000 or Pye CT200 - well, there was no comparison.
I wonder if there was a general manufacturing problem in Japan at that time as the corrosion problem mentioned above wasn't confined to these sets - the Hitachi CWP132 etc (NP6) suffered in the same way with solder lifting off the copper pad.
As the good captain says you need time and patience, and those were in very short supply in busy repair shops in the Eighties!
Glyn

[DangerMan]

Hi
Another thing to remember is that some of these sets were the first Sony ones made in south Wales, and our first delivery of UK built sets was KV1810UB mkII's. They had been anglicised to a large extent, using many locally sourced parts with appropriate design changes. These components weren't the main problem though, and the Sony rep's stance was that with the poor reputation of British sets, these sets had to be better than even the native Japanese sourced ones.
These sets certainly gave a good picture straight from the box, but ran into a reputation for short crt life, which, ISTR, was put down by some to over-vigorous activation of the cathodes in the crt plant.
Yes, they were certainly tame-able, but unofficial modifications were most definitely a big no no back then. If any such modified set had caused a fire or other serious trouble in a customer's premises the repairman that did it would have been on his own, big style. Also, any unofficially modified set that made its way back to Sony would have been frowned upon, a black mark against the service centre that did it. (i.e. if it had been us!)
One thing that annoyed me about them was the poor HT regulation: the picture size oscillated in and out at every sudden contrast change. We even had a customer complaint about it, which we passed on, but with no outcome.
I/we must have sold and repaired hundreds, and TBH you could eventually come to almost like them.
But not quite. Sorry.

Pete

[hans]

I don't remember much about these sets, but I hated them. Those GCS were so expensive the sets were BER if the two GCSes needed to be changed. The sets in general weren't easy to work on either. In the end of the 80's the 1810 sets were dumped without trying to repar them, any good GCS were salvaged and used in 1820s. This was more economical than fixing the 1810s. I think the GCS would cost 50 £ each. I could get a BU208, boost cap, LOPT and remote for most other sets for this price.

Haven't seen a 1810 since the beginning of the 90s

[neil29]

I used to have one of these sets. it goes without saying that it was dead on arrival and i never bothered to repair it as when i had a look in the back it put me off looking at all the stuff packed in to it. i think someone on the forum had it? can anyone remember who.. cheers neil.

[Kurleyuk]

Hi guys, new to this forum. I used to repair these in the days when I was a TV tech. Biggest problem causing the SCS devices to fail was an arcing on off switch. It is of an open type, have a look for signs of arcing on the contacts. If not too bad they can be dressed with a needle file. If very bad replacement is the only answer. A decent vdr across could help to reduce transients from destroying the devices. I hope this helps.

Kurleyuk

[slidertogrid]

Originally Posted by hans9001

In the end of the 80's the 1810 sets were dumped without trying to repair them

I must admit I had much the same attitude with these sets, Ex rentals were scrapped if they didn't work, if they did they were used as loan sets untill they didn't, then we reverted to plan A
The danger with these was the chargeable customer repair, the risk of a under gurantee repair was high and any re repair meant you had spent more than you made in the first place, so usually we put a high estimate on them and warned about future reliability.
I know someone who did the "Television" mods which ISTR entailed fitting a line driver transformer? He had all sorts of problems and never did get the set to work properly.
Sorry, but if I had one of these I would take it for a long walk... on a short pier!

Rich.

[Alastair E]

I had an KV-1810UB for well over 20 years. I got it given to me, --it was dead with both GCS short....

Following the article in Television, I adapted the idea to what I had around.

It ended up with the PSU rebuilt as Sony intended with the GCS and the line-stage had a BU508A and a Philips 'G8' Line-Drive transformer, the line-drive transistor, I Think I used an MJE340, and supplied that stage from the 130V? HT rail instead of the 19V line...

All electrolytics were replaced in the PSU and the line-stages, also, That Large Blue coloured epoxy 0.22uF, 1500V? (I think) that lived on the tag-strip under the line panel...
--This cap has a very hard life, Scan-coil coupling I think....Gets pretty hot--even with everything running normally.

This set ran perfectly like that for best part of 15 years, then went dead. I never investigated why, and passed it on just this week to another Forum member....
The tube was excellent, and I put a 2.2 ohm in series with the heater--this seemed to keep the emission from fading, as the picture the day it failed was as good as the day I had it first working....

- The heaters always seemed to me to 'glow' too bright on these sets, so thats why I added the 2.2 ohm......

IME, Sony always seemed to run the tube-heaters very hard, contributing I believe to the shorter than expected life of the crt.--They nearly always seemed to fade and take on that greenish hue...

[ariston]

Gettza123, pls, can you send me the manual sony.
My E_mail Removed by moderator
Thank you a lot