Luxor 3694 (salora L1 chassis) - Page 1
Forum section: electronics / beginners

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 03:12:49 pm
content: HiIm a litle stuck on this tv, its a early 90's 14" crt.I had it sitting in the basement for around 5 years and desided to use it again for some old consoles i got, i plugged it in and it did turn on, had a picture for maybe 30 sec before the cap on the mains blew up.It was a 250v 100n X2, i replaced it with a 220n at 270v i had in a power supply.http://eriko-software.com/schema.pngCN02 is the one that was bad, CN01 was swapped to CN02 and the blue X2 220n was put in to CN01.Problem now is i have standby power, but as soon as i turn on the tv the frontpanel dies, and there is no life at all,I measured 400v on CN06 but that is a 375v 220uf im not sure if this is normal, it has 300v printed on the board itself on the trace for that cap so 400 seems high.Im pretty novice on these things, i was thinking maybe CN08 shorted and backfeed 750v to the 300v line ? im not sure if that is even possible, i did see a 1k400 that seems to be a 400v overvoltage protector but i do not see it on the schematic, but is present in the tv right next to the cap that blew, i was thinking if there was a backfeed of 750v that protector is the reson it is limited to 400v.I have never seen a cap go out in style like this onehttp://eriko-software.com/blown.jpgThe CN08 cap i suspect is shorted do look like it took a beating but the values on it is unreadable, i want to replace the resistors there to but i got no idea what wattage these are and i was hoping someone might be able to tell from the sizeshttp://eriko-software.com/capacitor.jpgI really hope i can get this up and running again, i had this tv since i was a kid, alot of good memories

author: Benta
author_rank: Super Contributor
timestamp: July 13, 2017, 03:26:50 pm
content: When a TV dies like this, it's in 95% of the cases the horizontal output stage. You can't do a lot other than start tracing voltages forward from the mains input, which is a nasty and dangerous job. Be careful.

author: CJay
author_rank: Super Contributor
timestamp: July 13, 2017, 03:33:53 pm
content: Good memories here too, my first paid job was working at a TV shop and we were Salora Luxor dealers so I remember the Salora tellies with fondness, they were lovely but the IPSALO had a reputation of being a bitch to work on.Fortunately they were really reliable.So, first, there's no good reason why those filter caps dying would have messed up the main PSU unless a bit of it has fallen into the PSU somewhere but it's an old television so who knows what else could have been on its way out.With 240V mains you should see around 340V on that main smoothing capacitor, have you checked the bridge rectifier is OK?Check the TN01 S2000AF transistor as well but I'd expect it to blow the mains fuse if that was dead (I think you might be able to get away with a BU508AF if it's dead and you can't find an S2000AF).The 100K resistor RN01, the 100R RN02 and DN02 are all suspects and, weirdly, so is the mains switch, I can't specifically remember if this applies to the Salora Luxor tellies but many tellies of the time had a second set of momentary contacts that sends a startup pulse to the SMPSU, if that fails then it won't power up.As always for anything that old, check low value capacitors and high value resistors, they dry up and go high in value respectively.Does yours have the 12V DC camping power supply bolted on to the bottom of it?

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 03:42:47 pm
content: yes it has the 12v at the bottom, i measured 400v with it unplugged at that cap, the fuse never blewThe switch was damaged when the filter blew, i should have mentioned that i bypassed the switch for the mains only, the low voltage part of the switch was still functioning and is what i use to turn it on with, maybe the switch is the issue after all.

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 04:49:20 pm
content: RN03 meassures 270 ohm, did i read it wrong? i was sure that is supose to be 27k and RN34 is identical and also measure 270ohm, they where both connected to the same pad, RN01 is wide open, rectifier looks ok, got about 0.400 across it in one direction none in the other.the ba159 seem to be ok

author: CJay
author_rank: Super Contributor
timestamp: July 13, 2017, 06:27:38 pm
content: They should have colour codes so check if the resistor is meant to be 270R

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 06:37:10 pm
content: RN01 is measuring 100k as it should, was my meter messing it upRN02 100ohm as it should be.RN03 270 ohmRN04 meassure correct as well 47 ohm.schematic seem to say 27k on RN03 but i guess that must be wrong, what is in the tv is a 270ohm and matches the color code, Red, Pink, BrownThis tv has never been repaired before, so that is the part it came with.DN02, DN03, DN04 conduct in one direction, open in other.rectifier conduct in one directing only between AC and DC.Capacitor CN08 not shorted.I dont know how to check the S2000 but i think i can asume that is ok as well. so the power supply part seem to be ok.Any other ideas on what this could be? im leaning on that switch a bit, is there a way i can bypass the low voltage part of it, it do switch between 2 connecting points when i press it, released its connected to one pin pressed it connect to the other pin, and it seem to send the pulse since the tv go dark after its pushed.Im wondering if it should be between the 2, floating if you like when the switch is in the on position, problem with the switch is it does not stay pushed in when you press it, and i noticed half way in it seems to be floating.Im pretty sure that switch is impossible to get a hold off these days.

author: CJay
author_rank: Super Contributor
timestamp: July 13, 2017, 06:46:03 pm
content: You can replicate the function of the switch though, at least for testing.

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 06:54:34 pm
content: im not sure what the correct function is, but i guess i could try and unsolder it and hook another switch to pulse it but leave it floating after the pulse and see if that works

author: TomEV
author_rank: Contributor
timestamp: July 13, 2017, 10:16:20 pm
content: i think i found the issue. dont have time totest it until tomorrow its getting really late here, but the neck board ribbon was not plugged in all the way, i think there is a return from it powering a winding on the transformer that powers the high voltage and yoke.

author: TomEV
author_rank: Contributor
timestamp: July 14, 2017, 08:04:39 am
content: no change putting the cable properly in, but, i floated the switch and it now turns on, there is krakling in the audio no image, and dead front panel, a faint whine or beepinng like like what you hear when the HV is running, and i mean really faint, not like a short or bad supply, but i dont think there is any hv to the tube, and no smoke wich is always a good thing

author: Benta
author_rank: Super Contributor
timestamp: July 14, 2017, 10:39:53 am
content: The faint beeping could be from the driver transformers for the horizontal power transistor, which leads me to think it's blown like I mentioned earlier.

author: TomEV
author_rank: Contributor
timestamp: July 22, 2017, 09:00:48 pm
content: Been busy with other things for a while, but the current state is, Front panel lit up like it should, press the power button and let the low voltage part for the turn on pulse to float, the tv keeps turning on then imediatly off again, about 2 sec passes and the process repeat itself, letting go off the power button stop the startup loop but do not light up the front panel again, cutting power and turning it back on restore the front panel.The faint beep i talked about seem to be just the powersupply, and its very faint, if i had the back lid on, i doubt i could hear it, the only thing atm i find really confusing is that the Filter cap reads 400v, its rated for 385, and 240v threw the rectifier and cap should give me about 340v or so, even if the line voltage was a bit higher it would have togo very high to pass 400v.I will check the transistors next, at least make sure they are not shorted, from my understanding the resistor betwen base and emitter is not built in to these ones so i can check this like a normal transistor?It can very well be the Horizontal has gone out as mentioned if so its one big coincident, i dont see how that would blow from the X2 cap on the main blowing up, if anyone could explain how that could happen that would be greatim trying to learn what i can as i go along with this.I should also mention that while sparks where flying when the X2 blew, there was still a image on the screen, that didnt change until i pulled the cord.Im no expert in these things so what im about to ask might be a silly question, But when i replaced the X2 with a 220n instead of a 100n is it possible that caused less ripples causing the DC voltage to become higher on the filter cap, and because of this everything is getting overvoltage, and the set goes to shutdown because of this? its the 400v on that cap i do not understand.The line voltage is 236v

author: TomEV
author_rank: Contributor
timestamp: July 25, 2017, 12:26:58 am
content: Both S200AF meassure the same, ether both are bad or they are both good, no shorts.336v on filter cap CN0622v present,12v and 16v missing.170v missing,8,5v is present.33v present.N02 to low, only 7v should be 35vN03 not present, RN05 good.DN14, DN21 goodRN27, RN28 goodDN13 good, RN23 seem to not exist on this board.CN34, DN05 goodSo it seems everything on LN02 and LN03 is missing, exept the 33v output on LN0222v i m measured was on the switch, not the output from LN02

author: TomEV
author_rank: Contributor
timestamp: July 29, 2017, 08:41:08 am
content: http://eriko-software.com/schema.pngPin 5 on IN01 is 37v, following that trace, schema says 118v RN28 is good and i get 37v on both sides of it, 118v is what would drive N02 and N03 if im not mistaken, Am i looking at a bad transformer? i know the main voltage is good with 336v now.I checked the H output stage from LN05 to the yoke, nothing bad in that part of it. and TN03 act like TN01 so i asume they are both good, they are not shorted.Any ideas?

author: TomEV
author_rank: Contributor
timestamp: July 29, 2017, 09:00:23 am
content: Quote from: Benta on July 14, 2017, 10:39:53 amits from the TN01 area

author: TomEV
author_rank: Contributor
timestamp: July 29, 2017, 09:03:24 am
content: Im not sure if this is related, but when i press the volume button in standby the 7 segment display start acting up by showing dim segments in areas it should not, goes back to normal when the button is released, im sure it did not do that when it was working.