M68QDY259X 02 LG Philips Monitor Issue- Clicking, Anode Cap Removing & Green LED

[s34n]

Hi There,

I recently purchased a cabinet with the following monitor:
Monitor: Wei-Ya Makvision Model: M2929D1-62 and 4827F1
Tube: M68QDY259X 02 LG Philips

Upon giving the monitor power, you can hear a slight audible clicking, like a clock, with roughly 3 seconds between each click. There is a Green LED towards the front of the main board (closer to the screen) which lights up when each click sound is made.

When the cabinet arrived, the monitor's anode cap was not plugged into the back of the monitor. I pushed it back into place, and this is how I gathered the above diagnostics. When looking at the monitor the next day, the anode cap was hanging off again!

If anybody has any insight on why this is happening, please let me know! I do not know an awful lot about monitors, but I have done some studying. I guess the obvious questions to ask would be...

1. Does the anode cap simply remove itself unless some sort of glue is supplied? What does the inside of an anode cap look like? It just looks like a small clip which clips into the back... Was really wondering if anything was missing.

2. What is the clicking noise? I read that the power isn't being supplied to the rest of the board to prevent further damage, so the Green LED and clicking noise tells you this. I also read that the likely suspect could be the HOT (Horizontal Output Transistor)?

Thanks for reading and any help is greatly appreciated!

[grantspain]

what model monitor is this,you have only given the tube number

the anode cap has to be clipped into the hole in the tube not just pressed into place

[s34n]

Hi There,

Thanks for the reply!

Monitor: Wei-Ya Makvision Model: M2929D1-62 and 4827F1

[grantspain]

only worked on one of those,yes i would start by reading the horizontal output transistor

[s34n]

I managed to find the schema here: http://na.suzohapp.com/pdf/service_pdfs/makvision-schem49-2717-00D2rev.pdf
It's way over my head!    I was trying to work out which pin is the collector so I can test.

Is it possible to test the HOT while it's already part of the circuit? Or would I need to remove it?
Should the monitor be discharged in anyway for any of the above two outcomes?

The only reason I ask is that I don't want to blow the multimeter!

[lilshawn]

the 2929 is a fairly good monitor. they do have an issue with bad caps though.

take a look at the electrolytic capacitors and see if any of the aluminum tops are bulged up (they should be flat). That said, they can go bad without showing anything. (google "bad caps" for pics of more bad caps than you can shake a stick at)

the click you hear is the power supply portion of the monitor beginning to start up, (voltages start coming up and the capacitors charge up to their full state) but senses an overload condition, and then shuts down. It's designed to wait a short time, then try again to start (in case a small power sag is the cause of the shutdown) Most often bad capacitors cause a huge load on the power supply because they act like dead shorts.

you are going to have to visually check things over first, then if nothing obvious stands out, begin testing things.

[s34n]

Hi There,

Thanks for the reply! I gave the caps I visual inspection and they are seem pretty flat... some have a sticker on the top saying "OK", but look flat nevertheless.

How would you recommend beginning to test things? Do I need to discharge anything or remove any components from the circuit to begin testing? Or can I test everything with it remaining in the circuit?

I'm still unsure how I find the collector pin on the HOT to test that

[lilshawn]

first of all, i recommend having a good multimeter. something digital. I'm not saying go out and buy an $800 fluke or agilent. But spend 30 or 40 bucks and get a half decent one. 500V MINIMUM. something "autoranging" is best (albeit a little more expensive), especially if you don't know much about what you are testing.  It'll pay for itself in avoided frustration. if you have a particular store you will shop at that has a website (walmart etc), let me know, and i'll recommend something that's good and available.

secondly, what you are going to want do is remove the monitor and plop it on a nice big bench. a pad or foam in front so you can tip it onto it's front if need be and not scratch it up. bath towel, moving pad, foam, etc.

Third, make yourself some kind of adapter so you can plug the monitor into an outlet easier. You aren't going to want to drag the cabinet over every time you want to check it. nothing fancy. chop off a cord and use some wire nuts or something to get 'er on there. be safe...respect the white/black color coding. you don't want to mix up your live/neutral wires. you'll end up electrocuting yourself.

Fourth, DON'T ELECTROCUTE YOURSELF! this should be #1 but hey, i'm lazy, i just got off work, and i don't want to go back. Don't touch stuff while it's plugged in. Don't touch some stuff while it's NOT. lots of these capacitors hold 50+ volts...some of these capacitors hold 200 volts or more in them and they don't feel particularly nice when you touch them. anything over 40Vdc is considered HIGH VOLTAGE and should be avoided. Voltages greater than 50 V applied across dry unbroken human skin can cause heart fibrillation if they produce electric currents in body tissues that happen to pass through the chest area.


still into fixing it?  it's alot to absorb, but if you think you can tackle it... let's be sure you are really ready.

[ed12]

after the little pep talk sinks in..and it is a must to listen to shawn..
a un-spoken rule is if u do not have an esr meter..it is cheaper and alot less headaches just to recap it,they may look good.? ie not bulging or nothing running out of the bottom of them..but it is safe to say they are there way south..
there age alone is the reason

ed

[s34n]

Thanks for the advice!

I did really want to try and tackle it myself... It's not going to be a one-off thing, and I'm prepared to learn! I'm an expert in software development, but hardware seems more interesting to me as of late.

If I did buy a cap kit and the HOT was at fault, I would be right back where I started right? I don't like throwing money (although probably not that much) at something and hoping it works. I might be the only one, but finding out the problem seems more satisfying!

Over the weekend, i'll look into some multimeters see what I can find! It'll probably be an ebay special if you know of any decent brands/meters on there! thanks for the help

[lilshawn]

a cap kit will likely fix this. but as you know, not always the case. be prepared to put some extra time in if it doesn't work.

when doing a cap kit...go slow, take your time. change them one at a time. take note of the orientation of the cap...sometimes the silkscreen markings on the board can be printed wrong. noting how the original was oriented before removal will prevent explosions.

they don't make caps (or anything else for that matter) like they used to. I got some stuff with 40 year old electronics with old point to point wiring that have no problems whatsoever. I also have electronics i bought last year iv'e already had to fix.

they drive components pretty hard in these monitors nowadays. they run pretty hot and caps tend to dry out. I've resorted to putting fans blowing air over the chassis to try and get some more time out of them before they crap out.