repairing crt tv, start with recapping - Page 1
Forum section: electronics / beginners

author: 2takt
author_rank: Contributor
timestamp: August 28, 2019, 02:20:06 pm
content: hi,i have a telefunken palcolor bs 570 dv chassis 619. when i turn on the tv the screen is distorted this will go away after 1hour on(this time will shorten if the tv gets used more frequently).i think the vertical is the issue because the horizontel lines appear right to me.sofar i have cleaned the chassis, tube and case. i have reflowed the neckboard. used deoxit on all connectors.now i want to start with replacing some caps: neckboard, north south modul and the "control and teletext modul". after this i want to recap the mainboard of the chassis including psu and then finaly start with IC swapping.i dont find any datasheet on my caps, can anybody tell me what they are rated or give a number to the next rated cap? i have phoned rubycon germany, 4 distributors nobody could help me. this is the first time ordering caps by myself, i tryed to get into this stuff for 2 years but only ordered packs for specific electronics.my caps and series(i think) is:Rubycon CE WTosin TSMSamhwa SU or SQ(not shure about that)i have service manual for the tv but there is only the uF rating listedif anybody needs pictures just tell me. thanks for helping medaniel

author: 2takt
author_rank: Contributor
timestamp: August 28, 2019, 03:29:25 pm
content: forgot to mention i have searched the rubycon site for this series no result, also found a list for old caps but they only go back to 1998. mine are from 1990-93 (1m9310).tosin i couldnt find the site, only found toshin but i have read they are taiwan and tosin is japan!?i didnt look up the samhwa cap

author: MosherIV
author_rank: Super Contributor
timestamp: August 28, 2019, 05:43:01 pm
content: Hi.I would advise against replacing capacitors. You might do more harm than good.The need to replace capacitors came along with switch mode power supplies, they have high freq switching meaning they put capacitors through higher ripple currents, wearing them out faster.Old crt tvs would have linear psu with fly back to generat the 30KV needed to accelerate the electrons.Just fault find the bad cap in the vertical or horizontal timing circuits. This may be a ceramic or other non electrolytic cap.Good luck

author: 2takt
author_rank: Contributor
timestamp: August 28, 2019, 06:17:58 pm
content: hi mosherdont they go bad on theyre own(electrolytic)? and the tv is somewhere at 30 years old.currently i cant tell you which psu is used on my tv, i will figure this out in the next days.iam currently waiting on my in series esr tester, hope it arrives till friday. thanks i hope i find something.one last question i also ordered this cheap oscilloscop dso 138. the service manual says:the chassis is isolated from line voltage. the isolation point is in the line section.can i measure the chassis without a isolating transformer?

author: vk6zgo
author_rank: Super Contributor
timestamp: August 29, 2019, 01:32:40 am
content: Quote from: MosherIV on August 28, 2019, 05:43:01 pmNot necessarily, SMPS were commonly used in TVs from the mid 1970s.A few TVs sold in EU used a SMPS to supply both operating voltages & EHT, but this was unusual.Most TVs indeed used a transformer variously decribed as a " Horizontal Output" transformer, or an "EHT" transformer, or less commonly (at least in Oz) as a "Flyback" transformer.The electron beam "flyback" during line blanking requires a very fast transition in the current through the yoke, & hence the transformer.A multiple turn secondary produces high peak votages during this transition, which in turn, are rectified to provide CRT tube EHT.QuoteOP--- Your fault doesn't sound like it is necessarily a capacitor.I would nominate a dry joint or similar.If it comes good when the TV warms up there are two ways to approach it.(1)While the Fault is on, heat up various likely points on the board with a heat gun.(2) When it is warm, with the fault no longer evident, use "freeze spray" to strategically cool various likely points.(2) Is usually best to pinpoint the problem, as the heatgun can't target a very small area.

author: Brumby
author_rank: Unknown
timestamp: August 29, 2019, 02:04:25 am
content: Quote from: vk6zgo on August 29, 2019, 01:32:40 amI suggest you don't use your average DIY heat gun you might have in the garage that can be used to strip paint. It could easily destroy things.However, if you really must - be very,very,very,verycareful.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 29, 2019, 08:09:44 am
content: Quote from: Brumby on August 29, 2019, 02:04:25 amI have used just such a gun to heat components on boards, or for shrinking heatshrink, many, many times.Actually, they are pretty lousy at stripping paint.Their main advantages are that they are, at the one time, much cheaper, & more reliable, than the outwardly similar units especially made for use in Electronics workshops,It is easy enough to be careful when using them, but if it scares you, a hairdryer is more gentle.

author: MosherIV
author_rank: Super Contributor
timestamp: August 29, 2019, 08:17:57 am
content: I do volunteer work at a computer museum. The stuff we maintain ranges in age upto 50years old.We never re-cap any of it. Only the stuff 40+ years old do we even look at checking old caps.Even then, only really bad ones are replaced.

author: 2takt
author_rank: Contributor
timestamp: August 29, 2019, 12:28:59 pm
content: thanks for your replies.i have an hairdryer and no cold spray but i will order one today!i have read this chassis has often problems with bad solder joints. what i have thought is a cold joint would always requier the 1 hour warmup, but if i have it on today and maybe tomorrow it would be fine the next day in 15mins(this testing was done 6-8month ago). so i assumed its a cap thats regenerating itself but iam no professionel electroniks repair man.one has said it was a ic that caused his issue but didnt write which ic he had swapped.so the new plan is get this cold spray and see if i find something. if nothing then reflow all the joints.the boards look good to me the faults i have seen sofar are the big psu cap has little bulge on top.on the left side of the mainboard is what looks like capacitour fluid(dryed white lines). but there is only the audio board and no H or V stuff.on the neckboard there are 3 (i think for rgb) big resistors. the pcb it has a darker color here assume its from heat.ok 40+ years is a point! but i have read capacitor shell life is 2 years so i assumed 30years would make the electrolytik inside not so good anymore.can anybody tell me if i need the isolation transformer for testing with oscilloskop?

author: MosherIV
author_rank: Super Contributor
timestamp: August 29, 2019, 03:14:27 pm
content: Before I got rid of my old 29inch crt tv, I could visually spot the dry joints. Many of them did not cause any noticeable problems, so I left them alone.The tv did develop a vertical scan problem: top 15 lines would have larger spacing than normal. A good hit to side of tv sorted it out or just left it to warm up. When this stopped working, I looked up the vertical scan circuits, sure enough there was a dry joint in that part of circuit. Re-soldered that single joint and the tv worked perfectly.If you think there is a bulging cap, change just that one cap. If you have esr meter, confirm tha cap is bad.Leaking cap electrolyte is normall dark in colour. Still try and trace the source of the whit marks.Yes, it is normal for large power resistors to generate heat. If it is starting to badly scortch the pcb, that needs investigating. Be careful, the line scan coils are driven with a few hundred volts.The circuit on the tube rear also has the eht (30KV) so be very careful !Yes, old crt tvs should be powered through an isolation transformer if you are going to probe with oscilloscope.

author: 2takt
author_rank: Contributor
timestamp: August 29, 2019, 06:16:56 pm
content: here is the big psu cap 330uf 385v rated, so this one is bad

author: 2takt
author_rank: Contributor
timestamp: August 29, 2019, 06:18:53 pm
content: that sounds like my old sony always have to give him a little smack on the side xDi will check the rest of the caps with my meter then i begin the reflowing.so the isolation in the tvs psu is not enough for oscilloskop use?and here is the resistors and the white dryed fluid. hoPe you can see it

author: Gyro
author_rank: Super Contributor
timestamp: August 29, 2019, 06:59:35 pm
content: Quote from: 2takt on August 29, 2019, 06:16:56 pmNope, that still looks acceptable for a 330uFnon-SMPShigh voltage capacitor.

author: 2takt
author_rank: Contributor
timestamp: August 29, 2019, 07:47:38 pm
content: ok i found 1 and the display said good if <1000uf the cap was a 1000uf. so this should be good too?update my esr meter just gave up on me. had serveral zerroing errors. now it show 0L when shorted great

author: Benta
author_rank: Super Contributor
timestamp: August 29, 2019, 09:14:27 pm
content: In all the CRT TVs I've repaired (and they were many), the primary fault mechanism was to 99% solder joint failures. Secondary component failures then followed as collateral damage.The high voltage horizontal and vertical deflection circuit is the part of your main board that's most prone to failure due to high thermal and mechanical stress. Thermal, because it gets hot, and mechanical because the parts are heavy (compared to a resistor).A simple reflow of the main board willnothelp. A manual resolder/reheat will also not help.You'll need to remove the old PCB solder joints under the high voltage components (solder wick, rework station, whatever you have) and resolder them manually withEutecticelectronics resin solder (60/40 or close). Modern lead-free solder will not work on components this old.Why? The old solder joints have one or two issues.First, they're oxidized over the years and a simple reflow will not break the oxide.Second, There's a production issue called "Tin Depletion". Tin has a higher affinity to copper than lead, so when several thousands of PCBs have been run through the wave soldering machine, the solder is no longer eutectic, but lead-heavy. Quality manufacturers monitor this, but it was an issue 50 years ago.SAFETY ISSUES:1: make certain that all large capacitors are discharged (easily done with a multimeter).2: discharge the CRT. Connect a wire between chassis ground and an insulated screwdriver. Press the point of the screwdriver under the "suction cup" on the CRT.Let us know how you get along. Cheers.

author: MosherIV
author_rank: Super Contributor
timestamp: August 29, 2019, 10:12:37 pm
content: Hi.Agree with Gyro. That 330uF sounds ok.Generally speaking, most electrolytics caps have esr less than 2when good.If you measure more than 10then it is bad.Also agree with Benta. Your primary problem is likely to be bad solder joint some where.I did not know about tin depletion.I did as Benta suggested, I removed the old solder and re-soldered with fresh 60/40 solder.I did not do the whole HV section, just found the single faulty joint and re-soldered it.TV worked for at least 7 years before the next fault. Could have repired it (total loss of vertical scan, just left with bright horizontal line) but it was 20 years old, 4:3 aspect ratio so decided to get shiny new flat screen

author: 2takt
author_rank: Contributor
timestamp: August 29, 2019, 10:36:22 pm
content: so esr meter had a really bad cold solder point where the probe attaches. need to clean it tomorow, has a lot of loss solder on the pcb. but seamed to work fine.i did discharge the tv befor doing anythingthe caps seem empty to me(had a philips cdi psu that shocked me already)i already ordered a desolder station should arrive next weekmy solder is:https://www.rapidonline.com/stannol-535236-solder-wire-hs10-sn60pb39cu1-0-5mm-100g-50-3997is this ok to use? what flux do you guys recommend?i did notice that when i reflowed the neckboard that the solder points didnt look as shiny as normal.i will keep the 10ohm in mind when further testing. maybe i should ask a friend to look for the joints, 4eyes see more then 2.same thing happened to my sony 10years ago

author: Benta
author_rank: Super Contributor
timestamp: August 29, 2019, 11:23:36 pm
content: That solder is fine, there's no need to use additional flux, it already contains colophonium. You'll get wonderfully shiny joints after removing the old solder.Don't forget to discharge the CR tube, I'll give you one hell of a whack if you don't (up to 1 J)

author: james_s
author_rank: Super Contributor
timestamp: August 30, 2019, 12:22:35 am
content: Problem that improves as it warms up is a classic symptom of failing capacitors. The most common fault like that I see in old CRT displays is a worn capacitor in the vertical deflection circuit causing foldover when cold.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 30, 2019, 04:01:04 am
content: Another common cause of distorted ("folded over") vertical scans is that the vertical (& audio) output stages are fed with a highish voltage (usually around 150v) derived from an overwind on the Horizontal output/ EHT transformer.The 15kHz output of this is rectified using a halfwave rectifier, then filtered by a fairly small caoacitance, but high voltage rated Electrolytic capacitor.(This same system was used in the valve days, when it was called "boost HT")If the Capacitor fails, the filtering is radically degraded, affecting the vertical scanning.If the rectifier fails, the same thing happens, but more so, as the vert stage supply reverts to the quite low "start up" voltage, & will be unable to perform its function.Fix?----Easy, replace the rectifier or capacitor, or both.But wait! there's more!A trap for young players exists, in that the capacitor has to be a "high ripple" type.(Well, that's the old terminology, which I guess, translates to a very low ESR in today's talk!The rectifier is a "fast recovery" type.If you fit ordinary old caps or rectifiers, they will work OK for a few minutes then let the magic smoke out!No prize for guessing how I know this!Strangely, I first came upon this problem not at work, but on my Mother in Law's TV.It had the classic "fold over" symptoms, but my old Fluke 77 read the largely unfiltered output as around 103 v DC-----Not the 150v it was supposed to be, but, I felt "not low enough to cause the problem".When I dragged an old BWD home from work, I was confronted with a "copybook" display of a unfiltered half wave rectifier output.From this, I learnt another useful lesson.DMMs can be fooled by strange waveforms, although more modern ones may be able to tell the difference.I'm not sure, as I don't have a modern DMM.

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 02:46:01 pm
content: i have added the pictures of the screen on start up and after it fixes itselfi worked quite a bit with this solder and very happy with it. i dont want to find out how it feelsyesterday i saw a video from retromancave but the other way round, after the pc warming up the screen starts blinking and then goes completly away. he fixed it with recapping the whole board.i dont know what foldover means or is this my failure in the picture?the speakers have a bit of hum when the tv is on, so this does matter?i did find some low esr caps befor the meter quited on me yesterday.the rectifier is just an arrangement of diodes? like the full bridge rectifier containing 4 diodesi will post you an update if i find something with my now working esr meterthanks again for all your help

author: xmetal
author_rank: Contributor
timestamp: August 30, 2019, 04:33:14 pm
content: Quote from: vk6zgo on August 29, 2019, 01:32:40 amIt's also known as a LOPT (Line output transformer) in the UK.

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 04:35:35 pm
content: this green yellow white and red pieces in the picture, are this film capacitors?i only have found one cap on the chroma modul labeled 470uf 6.3v with esr of 0.219. meter says good if < 470ufi couldnt read all the values. will have to wait for the desolderstation then i will get the shielding/heatsinks out of the way.on the front input panel i have 331j (ceramic?) caps the meter just reads 0L is this normal

author: xmetal
author_rank: Contributor
timestamp: August 30, 2019, 04:45:19 pm
content: I think they're polyester film capacitors from first looks.

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 05:00:06 pm
content: the red ones says 0.12j so there are 100pf/0.1uf with 5% tolerance?

author: xmetal
author_rank: Contributor
timestamp: August 30, 2019, 05:25:18 pm
content: Quote from: 2takt on August 30, 2019, 05:00:06 pmI would say they are 120nF (0.12uF) 400V 5% caps.

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 06:18:35 pm
content: ok meter says 11.5ohm good if<10uf so they are good tooi got two that the meter cant measure, the green one(cant read the value) and a yellow one 4n7j100. the rest seam ok to me.i think i will do a testrun today or tommorrow, i got the ice spray but its flammable i dont know if thats a good idea on the back of my tv?this north south module is a correction for the planar? tube. isit possible to bypass this module and hock my yoke directly in the mainboard without destroying something?

author: Benta
author_rank: Super Contributor
timestamp: August 30, 2019, 06:39:25 pm
content: It seems you're a bit in over your head here.Like I said, start with the high voltage section, odds are your problems are there. Resolder everything.N/S and E/W correction are secondary, don't start fiddling with that until the basic functionality is right, which is making certain that your horizontal deflection, high voltage generation and auxiliary voltage generation works 100%. This is all in one 15625 Hz transformer/circuit, by the way.Pay special attention to the safety capacitors across the primary of the horizontal transformer. These need to be soldered 100% reliably.Cheers.

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 07:13:51 pm
content: first time working on a crt:)ok i will do that.can you tell me where this cap is?

author: 2takt
author_rank: Contributor
timestamp: August 30, 2019, 07:41:49 pm
content: look something was hidding under the plastic) i could spot 2 more but this was the worst of them

author: Benta
author_rank: Super Contributor
timestamp: August 30, 2019, 08:44:32 pm
content: Quote from: 2takt on August 30, 2019, 07:13:51 pmIt's the snubber network with LL02, CL04 and RL05. These make certain that the HVT does not produce too high voltages.But you're already finding the relevant places for resoldering

author: 2takt
author_rank: Contributor
timestamp: August 31, 2019, 04:05:14 pm
content: i have found this parts, i will add a pic in the next post(size too big)santa was here and brought my desolderstationi have found some black stuff looks like the big psu cap. in the pic bottom right*. i will update after i resolder everything*the forum rotated the pic

author: 2takt
author_rank: Contributor
timestamp: August 31, 2019, 04:09:13 pm
content: so here are the safety parts

author: 2takt
author_rank: Contributor
timestamp: September 01, 2019, 08:45:58 pm
content: i found 2 leaking caps the big psu cap had some brown crust on the underside and the other has even more. and it looks like this other is hooked to Audio 0V, like vk6zgo said.so how do i find replacements for this?the psu cap:330 uF 385V LL057 90009M HP 932040/085/56PhilipsESR meter: 0,046ohmthe other cap:1000uF 63V85°C (VX)9310(M)TaiconESR meter: 0,021ohmmeter says caps are good low esr.i got half of the board resoldered, hope i can finish it tomorow.greetings

author: 2takt
author_rank: Contributor
timestamp: September 06, 2019, 09:50:09 pm
content: hi i have finished the soldering today, and it works no problemsthank you for your help!i have attached the pics from the caps, i would like to get new ones. what do you guys suggest?

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: September 09, 2019, 11:21:58 am
content: The big one looks actually ok, the small one - not so. There is some corosion on the pins, so I would definitely exchange that one. The bigger one.... it depends. If you can afford it and find a suitable replacement, replace it.Depending on the city you live in I could look in my cap stock pile if there is a fitting replacement waiting.

author: Benta
author_rank: Super Contributor
timestamp: September 09, 2019, 08:06:33 pm
content: The big one's OK, the small one is leaking, which can be seen on the PCB.

author: 2takt
author_rank: Contributor
timestamp: September 12, 2019, 07:44:18 pm
content: the big one also had a round(leaking) mark on the pcb.i life in germany.i couldnt find any detailed information(again) about this two caps. the thing i found was:https://www.datasheets360.com/part/detail/tvx1h221m/381254941137251487/how do i find out what caps i need for replacement. so i already know they are low esr, what else is important besides the uF and V ratingi did notice when the tv is turned on there is a really small flicker on screen(noticeable on letters) but is gone after 10minutes. is this a normal behavior when cold?the image is a little bit curved on the sides, has this something to do with my repairing? i have the service manual so i can programm the picture to be square again. but have to check the "system voltage" first. it should be 148V, can you tell me where i have to measure?

author: SparkyFX
author_rank: Frequent Contributor
timestamp: September 12, 2019, 08:15:52 pm
content: Quote from: 2takt on September 12, 2019, 07:44:18 pmWe too... check the country flags. Which city/area?QuoteThe BNC ground is usually connected to protective earth, therefore it is not isolated in the sense of running the device-under-test with an isolation transformer. In most cases, all BNC sockets on the front panel share the same ground, so whatever you touch with the probe ground is live on those BNC sockets -> horribly unsafe to work with, without further provisions.QuoteCapacity, voltage rating, temperature rating, the footprint of the part, obviously. ESR is usually somewhat defined by type of capacitor.QuoteEven if the pillow setting can be done in software, first sort out the line transformer issue. These deflection grids are probably not working as intended when hit by the beam (lines that are not on the screen probably end in them).Replacing the leaked capacitors is probably a move in the right direction.

author: Gyro
author_rank: Super Contributor
timestamp: September 12, 2019, 08:21:52 pm
content: Quote from: 2takt on September 12, 2019, 07:44:18 pmLeakage marks... or just residue from board cleaning / normal environmental contamination? Hard to say but I think it is the latter - I can't see any sign of leakage around the terminal pins or bottom rubber, just marking on the end of the plastic sleeve.It's worth at least thinking about replacing some caps after you've gone to the trouble of removing them but consider cost also. The caps around when that TV was built wouldn't have been the same as the ultra-low ESR ones used in compact, high switching frequency, SMPSs these days.The factors determining capacitor replacements are capacitance value, voltage, ripple current (which effectively covers ESR too in these caps), temperature spec, and physical size / pin spacing. Remember that this is consumer equipment, the originals wouldn't have been exotic. With modern caps, you sometimes need to select a higher voltage part - simply to make the physical size big enough.It's easy to 'see' picture defects in CRT TVs these days when you're used to modern digital LCD TVs. A bit of flicker on an interlaced screen is normal, as is a bit of curvature (which can probably be adjusted out if it really bothers you), I'd keep adjustments to a minimum.The service manual ought to be specific on the voltage measurement points, often also marked on the PCB (with care!).

author: 2takt
author_rank: Contributor
timestamp: September 13, 2019, 05:23:41 pm
content: i didnt see the country flagsi life near kaiserslautern rheinland-pfalz.i think i will stay away with my oscilloscope from the tv. i will train me on lower volt equitment first! and i have no isolation transformeri will search for some spare caps, when i find something i will post it. so the only things that are importent is V uF and ESR. i will search for this over 100°C caps. i already read that i can go a little higher with V.deflection grid, what is this in german? i think the picture was square befor i started working on it but i didnt look for it.. so i will get the leaking cap new and then we will see.befor the pictures i cleaned the board with a vacuum, no liquids. the caps are a bit apart and there are other caps in between with no marks. the color looked the same(the small one had more gung so the colour was darker). on the underside of the pcb i found some black stuff(cap juice?)i found other caps with "colored" legs but there was nothing to see if something had leaked.i thought the same about the flicker, maybe it was this way. but it got away after 10mins and i used the program list of the tv, this shouldnt be an interlaced screen?!yes the service manual tells me the points, i searched the schematics but couldnt find them. i think i have to look again. the system voltage should be in the psu area?

author: 2takt
author_rank: Contributor
timestamp: September 13, 2019, 05:40:24 pm
content: for the smal one:https://www.ebay.de/itm/1-pc-NICHICON-Elko-Low-ESR-43mOhm-UPW1J102MHD-1000uF-63V-16x31-5mm-RM7-5-NEW/233128281101?hash=item364787440d:g:aKIAAOSwxp9W6Fftfor the psu cap:https://www.ebay.de/itm/2-x-330-F-330uF-400V-105-Snap-In-RM10-Elko-Kondensa-Samwha-Elko-SnapIn-2pcs/152860959292?hash=item239739223c:g:jB8AAOSwItFc1xBythis one doesnt say low esr. i found a datasheet, there is also no mention for low esr. its also smaller then mine 22mm to 31mmhttp://www.samwha.com/electric/product/list_pdf2/HE.pdfcan i use these 2 caps for spare?

author: Gyro
author_rank: Super Contributor
timestamp: September 13, 2019, 06:56:00 pm
content: Quote from: 2takt on September 13, 2019, 05:23:41 pmGood plan! Stay far away from the TV with your scope - a handheld DMM should be all you need for a CRT TV.Quote from: 2takt on September 13, 2019, 05:23:41 pmI would be surprised if the TV suddenly switched to non-interlaced when the program list is up, I think it will probably always be interlaced.Regarding the 148V measurement. Looking at your partial schematic in reply #28, it is the signal named 'USYS', the only place I can see it is on Pin 8 of the line output transformer, LLO1 (makes sense as it is the regulated HT line feeding the line output stage). The LOPT isn't the safest place to measure it though, you should be able to find it in the PSU area (not on the partial schematic photo).

author: 2takt
author_rank: Contributor
timestamp: September 13, 2019, 07:46:37 pm
content: ok this helps me. i have added the rest of the schematics. would DP56 be a good measure point?i should measure from the underside? because its near the line output transformer

author: Gyro
author_rank: Super Contributor
timestamp: September 13, 2019, 08:17:02 pm
content: I don't know if you have safe access to the underside of the PCB when it is operating. If so, then CP54 looks like the biggest target. Harder to mis-identify.Please don't do it if not confident in your ability.The safest way, after checking that the capacitor is discharged, is to solder on a pair of wires and attach these to your meter probes (and insulate) before powering the TV. Your hands are then free.

author: 2takt
author_rank: Contributor
timestamp: September 13, 2019, 08:28:30 pm
content: i dont want to get near the 31kv when its on, so the upsite i wouldnt do. i will check it tomorow if the cables are long enough for rotating 90° but your suggestion is great! i think i go with yours.negative i can get from the shielding? the neckboard has a black ground cable that goes the shielding of the mainboard

author: Gyro
author_rank: Super Contributor
timestamp: September 13, 2019, 09:06:41 pm
content: Quote from: 2takt on September 13, 2019, 08:28:30 pmProbably (without tracing it out). If measuring at CP54, you can simply measure across the capacitor - or at least continuity check between CP54 negative and the shielding first.

author: 2takt
author_rank: Contributor
timestamp: September 13, 2019, 09:38:48 pm
content: ok i will update the result tomorow

author: 2takt
author_rank: Contributor
timestamp: September 14, 2019, 06:56:04 pm
content: i got 148.3 v on start up and it goes up to 148,5. this should be good?i do a longer testrun right now.

author: 2takt
author_rank: Contributor
timestamp: September 14, 2019, 08:09:10 pm
content: still on 148,5vi added a pic so you can see its just a little offthe first line is displaying green red and black flickering. it disappears when i zoom in.

author: Gyro
author_rank: Super Contributor
timestamp: September 14, 2019, 09:44:50 pm
content: 148.5V sounds absolutely fine, you wouldn't expect absolute precision. From your photo, the screen geometry looks fine too.Regarding the flickering top line, I have no explanation other than maybe the picture height is set slightly low. This used to be easy to diagnose because on analogue TV broadcasts, you would see white teletext data bits flickering at the top, these would normally not be visible due to slight overscan.

author: 2takt
author_rank: Contributor
timestamp: September 16, 2019, 08:52:14 pm
content: ok good.i thought the same. do you suggest going trough the service menu and adjust the screen for perfect fit? i think i gonna leave it like this, because its done with bits and i never done this befor. of course i did it with a pc monitor that had a on screen menu.are this caps ,i posted, ok to put in my mashine?

author: 2takt
author_rank: Contributor
timestamp: September 19, 2019, 02:35:11 pm
content: so nobody is gone say yes to the caps.. does anyone say NO to this caps?