- Видео 12
- Просмотров 38 072
The Retro Bristolian
Великобритания
Добавлен 11 июн 2020
Bang & Olufsen MX7000 - Capacitor Replacement Service & Repair Pt.1
This video is Part 1 in an attempt to service and revive a Bang & Olufsen MX7000 CRT TV
Chapters:
0:00 Introduction & Overview
7:49 Removing the back cover
9:55 Overview of internals
10:50 Post basic cleaning
12:30 Looking up tube details for CRT health check
19:31 CRT tester connection and testing
25:50 Safe discharging of the tube
28:11 Showing removal of the chassis board set cage
31:50 Closer look at the cage assembly
55:03 Closer look at board 4 - the Power Supply board
1:10:25 Rant at how useless the B&O service manuals are
1:39:46 A look at the capacitor spreadsheet and summary of the progress so far
Constructive feedback is welcomed in the comments. Thank you for taking the time to view.
Useful ...
Chapters:
0:00 Introduction & Overview
7:49 Removing the back cover
9:55 Overview of internals
10:50 Post basic cleaning
12:30 Looking up tube details for CRT health check
19:31 CRT tester connection and testing
25:50 Safe discharging of the tube
28:11 Showing removal of the chassis board set cage
31:50 Closer look at the cage assembly
55:03 Closer look at board 4 - the Power Supply board
1:10:25 Rant at how useless the B&O service manuals are
1:39:46 A look at the capacitor spreadsheet and summary of the progress so far
Constructive feedback is welcomed in the comments. Thank you for taking the time to view.
Useful ...
Просмотров: 2 905
Видео
Archiving Documents - Nanao MS9 Monitor Manual
Просмотров 17010 месяцев назад
NOTE: This video is more about the process and the advantages it could service to better quality original documents, sadly the doc I used in the example wasn't all that great to start with. Please just bear that in mind! This video is an overview of how I scanned and archive a manual for the tNanao MS9-29 Arcade monitor. This video attempts to cover: - Disassembling the original document - Scan...
Nanao MS9-29S-E Chassis (Arcade Monitor) - Replace capacitors and repair
Просмотров 1,1 тыс.11 месяцев назад
This video is an overview of how to repair a Nanao MS9-29S-E Chassis with a Toshiba A68KJU96X 29" CRT tube. This video attempts to cover: - Cleaning the chassis - Removing and replacing all electrolytic capacitors - Repairing burnt pad/traces Chapters: 0:00 Introduction 1:34 Overview of chassis 10:46 Cleaning and removing dust from the arcade monitor 15:12 Looking at the neck board under the sc...
Nanao MS8-29FSG Chassis (Arcade Monitor) - Replace capacitors and repair
Просмотров 1,7 тыс.Год назад
This video is an overview of how to repair a Nanao MS8-29FSG Chassis with a Toshiba A68KJU96X 29" CRT tube. This video attempts to cover: - Cleaning the chassis - Removing and replacing all electrolytic capacitors - Repairing burnt pad/traces Chapters: 0:00 Introduction 0:45 Cleaning and removing dust from the arcade monitor 1:44 Light dust removed 2:15 Checking the deflection yoke measurements...
Bang & Olufsen Beolab Penta 2- Display capacitor replacement (Repair)
Просмотров 5 тыс.2 года назад
This video is a continuation of my miniseries on Bang & Olufsen Beolab Penta speakers. In this video I show how to replace the capacitors on the Beolab Penta 2 display. Chapters: 0:00 Introduction & Overview 0:11 How to remove display screen cover 2:24 Removing the display 3:08 Removing the board assembly 4:21 Comparing Beolab Penta display screen versions 7:30 Having a closer look at the assem...
Backing up, Archiving and Burning replacement EPROMs (B&O VX7000) (TL866 II Plus)
Просмотров 4182 года назад
This video is a start to finish guide of how to back up the EPROM Software/Firmware from a Bang & Olufsen product (VX7000). This video covers: the programmer, removing the EPROM, backing up the EPROM, burning a new EPROM and more. Chapters: 0:00 Introduction & Overview 03:06 Installing Programmer software 08:28 Setting up the programmer/software 11:07 Removing the EPROM from a VX7000 VCR 18:02 ...
Lear Siegler ADM-31 Terminal - Repair & Restoration Pt.1
Просмотров 6 тыс.2 года назад
This video is the 1st part in a miniseries of Lear Siegler ADM-31 Terminal. This video attempts to cover removing, cleaning, and recapping the power supply, CRT driver board, basic troubleshooting, and reassembly. Chapters: 0:00 Introduction & Overview 5:12 Disassemble the clamshell case 8:44 Discuss CRT discharge and safety 17:17 Cleaning the case 18:18 Cleaning the CRT tube 18:54 Using a CRT ...
Bang & Olufsen Beolink 7000 Charger - Repair & re-cap guide
Просмотров 1,4 тыс.2 года назад
This video is a short and rather flawed attempt at showing you how to service a Bang & Olufsen BeoLink 7000 table charger. This video attempts to cover removing, cleaning, and recapping the power supply, re-wiring the plug and basic tips. Chapters: 0:00 Introduction & Overview 1:27 Discuss the plug wiring 2:30 Disassembly of the charger 6:22 How to test the diodes 9:26 Desoldering old capacitor...
Repairing a Bang & Olufsen VX7000 - Pt. 1: Rebuilding the power supply
Просмотров 1,4 тыс.2 года назад
This video is the 1st part in a miniseries of Bang & Olufsen VX7000 VCR problem/repair videos. This video attempts to cover removing, cleaning, and recapping the power supply, basic troubleshooting, and problem analysis and how to find and remove the lithium battery. Chapters: 0:00 Introduction & Overview 2:20 Closer look at the VCR with faulty PSU 4:12 Removing the power supply 13:50 Looking a...
B+K Precision Model 470 CRT CATHODE RAY TUBE TESTER/REJUVENATOR - Overview
Просмотров 1,5 тыс.2 года назад
This video is an overview of the Dynascan Corporation (later: Maxtec International Corporation), (later again: B&K Precision Corporation) B K (B&K) (BK) Precision Model 470 Cathode Ray Tube Tester/Rejuvenator (CRT Tester/Rejuvenator). It seems over I guess 60 years of buy outs, mergers, model succession, there has been an extensive amount of brand alterations. And whilst B&K Precision Corporati...
Carthago Chic I47 (2006 Fiat 2.8JTD) - CBE Stair switch repair
Просмотров 1512 года назад
This video is an in-depth look at how I serviced and repaired set of CBE motorhome switches: Related part numbers: CBE, 106959 - CARTHAGO SWITCH SET (2PCS), 06C0162, 200253, 02-06-05942, 38100, 001937, 001936 Chapters: 0:00 Introduction & describing the problem 4:30 Overview of the switch and diagnosing problem 16:44 Desoldering the components 26:00 Removing solder mask and cleaning the board 3...
Bang & Olufsen Beolab Penta - Repair and restoration
Просмотров 16 тыс.3 года назад
This video is an in-depth look at how I serviced and repaired a Bang & Olufsen Beolab Penta amplifier. This video attempts to cover in extensive detail how to replace the following components on a Beolab Penta amplifier: - Rewire and replace the plug - Replace plug fuse - Check/Replace internal glass fuses - Replace main PCB electrolytic capacitors - Replace trim pots - Replace OPAMP - Replace ...
Hi there I just wanted to get in touch I have found out that the isue with my b&o mx 7000 is the flyback transformer. I have sent to to a locat tv repair place however they are saying they are strugling to finde the flyback transformer by any chance do you know the part no or a shop online west I could order the part. From do I can give it the the tv repair person. Or is it posble at all if I could get my tv back from them and arrange to send you my b&o mx7000 after watching your video and seeing how thoroug you are with everything. Makes me feel that you would be able to do a fantastic job as the people who have my tv do not comincstion very well and they have had it over over a month woukd i be able to arrange my tv to be servises and have the capasters s as nd parts replaced I would like to give it a second chance on life this tv is my only tv I have and I would like for it to last a long time if not woukd you please be able to help me finde the right replacement part the model no of my tv is Mx7000 16145127 I apreshste you are a busy person thank you gir taking the time to read this best wishes and thank you for the video
Beoparts-shop has moved to Danish Sound Parts (dksoundparts). It would be helpful, if you could update the links in the description.
Hi what sort of plating is required for the crt cage?
it was a Zinc plating with a clear passivate (sometimes called blue passivate).
Thank you very much for this video. It must have been a big big work to do.
Thank you for the kind words! it was a big job, but well worth the effort!
Excellent detailed video, top marks! I have a couple of questions: I've moved a pair of Penta Mk 2s from USA (120V) to NZ (240V). I have the service manual showing how to restrap the transformers for 240V, and it mentions the change in glass fuse ratings; are you aware of any other 'gotchas!' when changing supply voltage to Penta amps? One of my pair is, annoyingly, missing the plastic cover from the digital display; are you aware of any source for a replacement? Beoparts have nothing :-(
Hi there my mx7000 I was using it last night with my nes and all of a sudden ther was a static sound and then a crackle s as nd pop by any chance do you know if it’s fixable I live in the Uk
Hi mate, are you still repairing B&O's? I'm up in Cheltenham and searching for someone who's able to repair a couple of old MXs!
@The Retro Bristolian Did the recap do anything for the barrell geometry issue?
Hi. I bought an MX7000 yesterday. I really like him! I've set up everything I need, but the image is clearly more blurry than on my mx 4000. Is there any way I can adjust the focus of the picture? Are there any handles inside for this, like other CRT monitors?
Fantastic Video Mate! Ive managed to score a MX5500 and a MX7000 recently. will certainly be using this guide as reference when thinking about cap replacement and maintenance. Thanks so much! looking forward to pt2 of this video!
Hello! I moved to another place with the TV on truck, When I start the TV for the first time after the move. The LED in the upper right was getting less and less power now the TV doesnt start anymore. Could that be capacitor problem? The Led was blinking but I dont remmeber if it was red or green.
Hi, Thanks for this vidéo. I follow you from France. Are you agree to help me to repair nanao ms9-29a. I can’t set the image correctly. I make a vidéo to share the problem.
This video has been a great help repairing a pair of mk1 6603. Though I ran into a problem if you had any input. I replaced all capacitors and got the amp to turn on and green light. Though trying to set my trimpots I have tried two different multimeters and can't get any reading from 1R103 and 1R104 pin. Also when clamped onto end of loudspeaker output is only reading in the 30s and isn't affected when I turn the screw. The light is green on the amp to.
it measures in millivolts DC from memory, if you have an auto ranging meter you might have to change from AC to DC, try adjusting the range on your meter, try probing something like a AA battery to make sure you can read a smallish DC voltage. Thanks for dropping by, great to hear the video was helpful
I've the Mk2 model, but from one of them not heard nothing audio, but the Red light of amplificator is on. What is the problem? Should be one of 2 internal fuse burn? Who help me?
Many thanks for this valuable instruction! It was a very usable guide for me to disassemble my Penta 6631 and service it.
Thanks for dropping by with a comment, really glad you found the video helpful!
Hi great video, my MX4000 fizzled out last month and whilst there is some useful info out there online it's all old forum posts with very few pictures of the picture links are broken and yes i totally agree about the service manuals! Thank you so much for this video just gives me a bit more confidence to dig in and replace the caps. I know it will come back to life if I do change the caps out. This video will help a lot. Cheers!
Thanks for the lovely comment, glad the video will be of some use to you! I believe the MX4000 and MX7000 are essentially very similar inside. I would probably recommend marking the cables so you know direction/location and also doing one board at a time if you can, best of luck with the MX4000!
Great Video! Thanks. Try scanning the Nanao Ms9 schematics in grayscale i sometime find it better scanning manuals in that format than black and white mode Cheers 🤗
Thanks for the comment, I've recently just updated my script if you find it useful. I've also purchased a Fujitsu Fi-6770A as it has an A3 document feeder. I also completely agree with scanning in grayscale rather than b/w. the manual I was scanning in this video was clearly a poor b/w scan/print anyway, but I've just been archiving some high quality B&O manuals to my archive.org account and grayscale is 100% the way to go!
@@TheRetroBristolian Many years ago i found the same manual on eBay but unfortunately it got lost in the mail.😟 I was very sad and for many years i was after both monitor schematics Nanao and Sanwa. Keep up the great work in archiving your manuals, is there any chance of getting a scan copy of Nanao Ms9 and Sanwa schematics by your Fujitsu Fi-6770A in grayscale or other best quality possible? any help would be much appreciated
@@RestorationitemsOnEbay drop me an email (it's on my channel about page) the original manual is genuinely a scan of a scan from Sega UK and poor from factory sadly, but I'll show that in photos and scan them for you when I can probably next week or so
@@TheRetroBristolian I drop you an email not sure if you received it Cheers
@@RestorationitemsOnEbay I've replied to your email now, (check your junk mail If you don't see it). Thanks,
THANK YOU FOR THIS AMAZING VIDEO! Please make a video showing how to refurbish the crossovers next :)
My bang & Olufsen receiver to my Penta 2 speakers. I now have to use the speaker cable because the data cable does not seem to want to work it. Whether it be 4 pins to 1 speaker or 8 pins from speaker to speaker. But instead I have to use the speaker line input from the receiver. Before it went completely out I used to be able to get sound out of one of the speakers and the other one worked but I used to have to turn it way up till it came on turn it down and then sometimes it up and down a few times. Does this sound like a common occurrence and if so what's a quick or some what do I do to remedy that. The speaker sounded so much better through the 4 and 8 pin cables. I don't know if it's using the on speaker amplifier or the speaker amplifier from this receiver itself at this point. And I noticed that the green light at the bottom is on all the time.
very informative! my Dad recently got some refurbished beolab penta mk3 and unfortunately has developed a fault where the right speaker entirely cuts out while the left carries on as normal. they are daisy chained with powerlink cables with the right speaker (faulty one) is the beginning speaker. after a bit of troubleshooting we have found it to "come back to life" when the power cord near the base is given a litttle wiggle....looks like a loose connection from the power cord but neither me or my dad have the technical ability to remove things or considder soldering anything!? apart from sending it to B&O specialists, what would you recommend for someone living in the west UK? sounds like it could be an easy fix but my dad daren't open them up
That noise is normal. It's a wiper running over coils of wire. It's called a Rheostat.
also I cannot find specs does it do VGA? 31khz
so the MS9-29 is a medium res chassis doing 15khz and 24khz, there is a mod you can do to make it do 31khz but it is quite involved. if you want 31khz you should look at the later model which is 31khz compatible wiki.arcadeotaku.com/w/Nanao_MS-2931 info on the mod is here mikejmoffitt.com/pages/ms9-hax/
hello!! do you need an Isolation Transformer for 120v?
so these monitors are technically 100v as they come from Japan, but you can run them on 110v/120v, I use a step down transformer to achieve that in the UK, but the MS9 and MS8 don't NEED an isolation transformer, just step down. some monitors like WG monitors need a isolation transformer, eventually I will get one as it is recommended to increase safety. Thanks for dropping by and commenting.
Is it possible to disable the ambient light sensor in the top right corner so you can have full brightness all of the time? If you use a flashlight there the screen will get brighter. I think it’s too dim by default.
hi , only you can help me because you know the mk3s like the back of your hand, basically I sent the midrange panels to a specialized center to renew the suspensions, unfortunately when I removed them I didn't catalog the wires with the various colors, I was wondering if you could give me a hand. Greetings from Italy
I just came across your video. I notice it was from a year ago but no updates since then. What happened with the restoration? Please try to jump pins 2 and 3 on the com port and type on the keyboard and see if any characters are displayed. Look to see if there are brightness or sub brightness adjustments on the video board and try to adjust thrm
So, The update was, I took it to work, managed to create a separate circuit to power the CRT stand alone and generate the signals needed to make it energise, managed to get a green dot on the screen. in terms of the terminal, there was a comment from a fellow RUclipsr who kindly made some videos to show how a working terminal works - which is very useful and I will revisit this one day. At the moment personally I have a lot going on, my grans house has finally sold this week, she passed in 2022 so it's been a long and stressful road, I now have 5 days to clear the house and swap keys so that will be taking up my time. after that I'm trying to build a room for all my projects and work, but having issues with planning so it's delayed. Thanks for stopping by with a comment.
Used an ADM terminal in college to write 6800 assembly code and it eventually went to a teletype that could also produce punched tape. Then after college was able to use a TRS-80 Model-1 computer.
Gosh that set still looks stunning to this day
yeah they're cracking TVs with incredible sound systems
I’m searching for one of these monitors for my collection
I wish you luck with your search :-)
The mechanical design of that amplifier is gorgeous!! Looks great, a bit of a pain to work on 😂
yeah! mega pain to work on, especially if you aren't familiar with the design and it's your first time. When I did my first amp it was a real struggle, once I worked out a process it wasn't too bad. Thanks for dropping a comment!
Great video. Do you have an email address i can contact you on? I can't see it in any of your links. Wonder if you could service an mx8000. Thanks
on my RUclips home page there should be an about and an option to view email address. I do also have an MX8000 and will be looking at that in the future 🙂
That probe is really not gonna discharge the crt if it had voltage. The probe really is just a voltage divider of REALLY high resistance
Why won't it discharge it? there is a resistor between the probe and the ground point and it can be used to discharge as well as measure the high voltage.
Well it will but you wont see or hear it discharge. But it might be actually better to discharge for a second or two because of dielectric absorption.
@@TheRetroBristolian also if the crt has an anode capacitance of around 500pF and the high voltage is 25kV then it would take just over a second to discharge with a 1 gigaohm probe.
i cant work with gloves on my hands in electronics repair
I'm not a big fan of gloves myself! but if I'm using IPA to clean I try to wear gloves so it doesn't dry out my skin all the time! 🙂
When you get around to it, the small board between the neck of the CRT connecting the horizontal and vertical deflection coils, very likely to have a burned / cracked joint on one or more of the terminals on the PCB.
I did read about the deflection coil board, I'm hoping mine is OK, but I'll give it a look over for sure. I think I've already spotted some dry joints on the neckboard (board 3) - thanks for dropping a comment!
The "mystery" caps are "Samwha" brand. Also, the BIPOLAR caps are the best sounding type (of electrolytic cap) to use in the signal path. This is the kind of thing that takes quite a long time to learn on your own.
Ah, Samwha indeed, I thought it looked a familiar logo but without the text I just couldn't place it. interesting to know about the BIPOLAR info, I'll keep with BIPOLAR caps where they are fitted. thanks for dropping by with comments
Hi Jonathan. By any chance do you knowwear could finde a fly back transformer or know if the model part force b&oMx7000 16145127 My tv stoped working and I’m trying to locstecdd as part but findeing it hard thank you in advance
I've repaired and restored countless B&O products from the 1970's onward... and a couple tips for you. The orange caps are "LN" (low noise usually) and are a higher quality, used for signal path or power applications. They very rarely fail in my experience. And one more thing.... ALWAYS always always replace any surface mounted caps!
Hi, I hope you don't mind me asking. But my B&O CRT slowly turns blue after 10mins or so. It reverts back to normal when powering off and back on. I wonder if this is a resistor or capacitor problem on the neck circuit? I hope someone can give me a clue. Cheerio.
Hi mate, i suspect caps out of value or resistor causing a ready state... i dont know... yoke look familar, one of the tubes here has that style. Planning on picking up another flat screen based tube tomorrow from the same place... also... we running SWAG this weekend at Chipping Sodbury, drop in for ten minutes as a guest, let me know if you do by messenger.
thanks, I'll drop you a message today 🙂
This is really interesting! I have the same problem with my camper, same print plate and panel! Thanks for this 😀
Thanks for the email, I've replied!
Hi, great video, i have this crt monitor in my naomi arcade, i habe a problem, sometimes turn on and work perfectly, but another times sound turn on, but the monitor don't show picture, do you know if the problem is easy to repair?
if it's sometimes fine and sometimes not it could be temperature related or a failing component like the capacitors. with temperature changes either environmental or due to it running a cracked (dry joint) could expand or contract just enough to touch and restore functionality. I would say you should safely discharge the tube (so there is no voltage at the anode), remove the chassis and check the underside for a dry joint, with a strong light and a magnifying glass you should see if there are any cracks, also check for bulging or leaking caps. these chassis will all have high hours on them now and have been through a lot of heat cycles, also they'll be about 20+ years old so the capacitors are past their recommended and usable lifespan. Thanks for watching.
@@TheRetroBristolian oh thank you for the fast answer, I'll check the caps, I will keep you informed, thanks!!!
Is it possible to provide information for the mesh towels you are using please. I am doing a similar process and this method looks great. Thanks.
These were just hand wipes I bought for about £3, but they aren't really the right tool for the job. Kimtech wipes are a similar product and I believe the right tool for the job as other people use it to assist with flux removal. I've also recently switched from using straight IPA to an actual flux removal (dissolver) liquid with the wipes to mop up excess fluid, that helps with removing the overly sticky residue left on boards. Hope this helps!
ah good stuff, was thinking that the wider distorsion might be a cap issue, not electrolytic.. I know Mike 'the amateur' has done a video somewhere for this on another chassis as I pretty much watched all his videos.... i think i recognise u now from ur reflections, think we spoke about Vampire Nights with Luke on top of Matts PL warehouse
Howdy, thanks for watching, and yes indeed my ugly mug in the reflection has been spotted - we were speaking about Vampire Night and other things. I need to get down and see Luke and the guys soon, I've just got back to the UK as have been in Iceland for a few days. As you say Mike has done videos showing something along those lines probably on a WG monitor, when I get to the point of actually recommissioning these monitors into use I'll have to compare the MS9s I have and maybe speak to Mike and see if I can get to the bottom of why. Thanks again and hopefully catch up soon.
@@TheRetroBristolian Awesome, will be at Timewarp Tuesday afternoon/evening on repairs and Luke will arrive later on. Also doing a bit with Playback at Galleries. Iceland so ur familar with the cold
@@DaveRepairs funnily enough Iceland is warmer than Bristol is at the moment, a lot warmer! If you get a second, can you drop me an email to the email address on my page contact details, I'll reshare my personal contact details, It would be good to tie up soon. (maybe Tuesday if the invite is there), I work next to the Galleries and have walked pass that playback quite a few times and have been meaning to go in. This year I really want to ramp up my game and do a lot more repair videos and do some collaboration work. I did say to Luke about coming down and scanning a load of artwork off the machines for him and helping if I can in anyway.
@@TheRetroBristolian Im back - Got my own Gunblade MS9 to review and got Craigs Astro City to improve. Hoping they cross compatibile with tubes so i can test it on my gunblade tube ? who knows ... starting to study and order parts
This h linearty issue is due to the values of the last film caps of the H stage, the two green one near the h yoke connector. The last one cap is bigger for Hitachi tube also the heater resistor is different and you want have 3.3ohm for Toshiba tube, you can check this is near the flyback, on ms9 chassis witch prepped for Hitachi tube is 1.8ohm
Hello, I have a problem with one of my beolab penta mk. 3 6631, I hope you can help me. One of them is having a humming noise from the amplifier, not from the speakers, only the amplifier. Is is like a small electric humming, not a deep sound. It doesn’t amplify when the volume increases. And usually it starts after I have used it for a little while. Newer when I turn it on when it’s “cold”. They are both speakers running at 56 degrees Celsius. When I have been pushing them at high volume. They overall sound great. I bought them, and tried them shortly to see if they worked, then I refurbished the 4 midranges in both speakers. So after that, I noticed the fault. Are they doomed? Did I mess up the wirering? I really need some expertise. Thanks for some great videos. Best regards Ben
A great video and guide... keep up the good work!
Glad you enjoyed it!
Great video.. think this is in one of my cabinet so will have to use this to help restore/repair!
I just bought one of these and am waiting for it to arrive. My first thought would be remove the CRT and CRT power board from the equation. Can you pull a composite video signal from the logic board and send it to a known-good external video display? You might feel better spending time trying to fix an old analog CRT if you could see that the underlying brain of the terminal was already working, or if you should focus on that instead.
Hehe capacitor 😊
The keyboard looks crunchy. What switches does it use?
How do you know what model number CRTs it works on? My CRT 25VGDP22 CRT tube model number
I kind of feel like you've missed the point of the video a bit, I put a lot of effort into uploading all the documentation and providing the links to everything you would need in the video description. you simply take the tube model you have, go to the tubular site and search for it, I even demonstrate that in the video. I've done it for you here - tubular.atomized.org/tube/25VGDP22 It seems that tube uses the CR-24 neck adapter. This is a somewhat common adapter, you follow the steps I take to setup the rejuvenator with the values found on the tubular site. I hope that helps 🙂
Have you made any progress on the terminal. I have one of these still in use on radio automation equipment. Make sure the contrast and brightness pots are ok and turned up. The solder connections on the pots can get lose. Also jump pins 2&3 on the serial connector this allows you to type and locally display. This will verify that the cursor is not hidden off the screen. As the pots were cleaned it’s possible the data is there just off screen due to size and position adjustments on monitor board. The high pitch whine noise is a good indicator that it’s possible out of adjustment with sizes causing yoke to deflect beam off screen. Some high pitch sounds are normal from those CRT’s. Mine has given issues with the bright and contrast pot on main board from getting dirty over years and causes blank screen issue. Try simple things first. Sounds as if the terminal is working. If you have a serial cable connect and set rates same and use a pc with terminal emulator and send and receive from keys this will check the communication. Might need null modem adapter or custom build cable
It's back in storage at the moment. your points are very interesting though for sure, when I get back to it it's all things to try. do you have an ADM-31? or a similar terminal? it would be helpful to see a video of one powering up, and being used - Thanks for stopping by and offering help/support.
@@TheRetroBristolian I will do a video of my terminal and a few test results as well that you can try.
Here is a video of my ADM31 ruclips.net/video/i4m1EwCxV-Y/видео.htmlsi=OtRvgYO-hCx_kOEZ
Here is the second video I done on sync pulses measurements from the SMC CRT controller IC. ruclips.net/video/37neAAYg7xY/видео.htmlsi=WDL4_TMgUr2Xr9xs
@@rick601a I've watched both videos and have to say the information is fantastic! So much for me to unpick and test, very interesting how early your terminal is and how it has the different PSU and monitor. When I get more time I will do a follow up video next year and of course drop credit to you when fingers crossed I make some progress.
So 90% is power supply for h-sync and v-sync is down