Proview LB 2006 W Monitor

[momaka]

Re: Proview LB 2006 W Monitor

Had to skip some days working on the monitor as my back complained about the workload, but it was actually a bad nights sleep, turning around and around that caused the old problem to become really bad, but after some days on painkillers and other chemicals from the doctors, I'm back to business.

No problem. Glad to hear you're feeling better, though.

Yesterday I repaired a Mercedes Benz outside temperature sensor that cost as a spare from Mercedes 64 Euro + vat(18%) and the only thing wrong in it is a 50 cent thermistorv (3k3 pearl NTC) so it was well spent time and I left an article about "how to" with pictures on our local Mercedes Benz forum.

Nice!
When it comes to cars, my hands become tied in a knot . I do have a general idea of how everything works, but much rather not mess with it (always keep thinking I'll break something).


Anyways, back to the monitor...

On the monitor front I am still digging as the 5V external supply is trying to drink about 2.5A and the diode goes hot very fast (it's still OK) (U11 does not get warm!).

2.5A is way too much. If diode D10 is overheating, there is definitely something bad down the line of the main boosted voltage rail. It's weird that U11 is not overheating - it should be as it tries to boost that voltage rail to +10 or more volts. Also, did fuse F5 blow?

I removed C 12, C13, C15 and R16 and 520 as they are the ones that are directly connected to the cathode of D10 and gave me a reading of about 10ohms over each of these.

Yup, that's definitely a short. What's very strange is that this didn't appear the first time you measured resistance between cathode of D10 and ground.

Now that you have removed R16 and R520, is there a short on their pads (i.e. the side that is not connected to cathode of D10)?

Also, have you tried removing C11?

When unsoldering R 520, it jumped from my tweezers over my workspace and I spent about 1/2 our trying to find it but no luck.
As it is just a 0 ohms one, I can replace it from a scrap board with a lot of SMD components on it (a t-con board I saved from a broken Medion monitor screen).

Yes, pretty much anything would work, even wire or solder blob. Don't replace it yet until we find the short, though.

It will be a bit of digging as after the resistors, the track seem lo lead to a second or what knows layer.
On one of the pic's of the t-con board you can just see the track from R16 to one of these through holes and the one from R520 is close to it.

One of them (or maybe even both) most likely go to U14. Check with your multimeter. If so, check the ceramic caps around U14.

If you have any time, try rechecking all of the ceramic capacitors again. Keep in mind that some of them may have leftover flux from manufacturing, which may throw off your readings. When measuring SMD components, scratch the SMD component's pads a little bit with your multimeter probes.

Hope to get on with it tomorrow, but it begins to look as a not so easy one.

Yes, it's getting a little harder, but as long as U11 isn't shorted, this should be repairable. Speaking of which, try measuring resistance between pin 22 (VDD) of U11 and ground. Also, measure resistance between pin 22 and the output of fuse F5 (or you can also use anode of D10 and the two pads on L2). Let me know what measurements you get.
-The AAT1164 datasheet states there should be a 10 Ohm resistor between the 5v rail and pin 22 (VDD), so ideally you'll want something close to that.

[Joseph67]

Re: Proview LB 2006 W Monitor

Hi again Momaka,
Today was a family day and I was not allowed to close myself up in the hobby room.
As on your notes:
2.5A is way too much. If diode D10 is overheating, there is definitely something bad down the line of the main boosted voltage rail. It's weird that U11 is not overheating - it should be as it tries to boost that voltage rail to +10 or more volts. Also, did fuse F5 blow?

The fuse did not blow as it is apparently a slow one and I in no moment left the external 5V applied for more than a moment to take readings.

Yup, that's definitely a short. What's very strange is that this didn't appear the first time you measured resistance between cathode of D10 and ground.

Indeed as in the first round of checking it read 228 ohms to ground, but as I noticed D10 getting warm, I checked once again resistance to ground and now it was about not 10 but 100 ohms???(my fault in writing), still, 100 (0.10 on the 2K scale) is not the same as the 228 from the first go.
I did not mention it but when removing all these C's and resistors, I also removed C11 as it also goes from the cathode to ground.

Yesterday night I had another short session and measured from the the pads to ground, R16 read 192 ohms to ground and R520 has 334 ohms to ground.
This is still no reason why I was measuring the 100 ohms but with the resistors and capacitors gone there is an infinite reading from the cathode of D10 to ground
As soon as I find some time I will try to follow the tracks from these resistors, but one of the weird things of being retired is that one has less free time for hobbies that when you are still working.
I sometimes wonder where I found time to go to work with all the other things I keep now busy with.

Obviously I also spend some time on my car, a 20 year old Mercedes Benz 300D I bought just a few weeks before retiring and was meant as a hobby object (€1200.-).
There was a lot to be done than, but now it is mainly details like adding some of the extras you could order on a Benz when buying it new.
A lot of them are gadgets you can have now in the new cars as standard equipment but it is fun to include them by getting the bits from a scrap yard and we have some really interesting yards around Madrid.
Yesterday morning I went with my son in law to one of the biggest and best organized ones and found some almost new front brake disks and mine are a bit worn after 20 years of use so when we got home the first thing was to remove all the rust and they are now ready to be replaced.
You see... more time gone to the car...
I am fortunate that when I was planning to get into a technical profession, we had at that time 2 ways of getting there, one was after primary to go into some boring 3 years administrative something schooling and than on to technical high, the other way was technical school (mechanics, tooling machine use, welding and the lot), than a bridge class of basic electronics and electrics and than on to technical high.
I took the second -longer- way, but have a wider base than many of my colleagues and manage to help myself and some other people out with cars.
I am now - sort of - specializing in the Mercedes 300's as the diesel and gasoline are basically the same car with only a different engine.
Here is why I sometimes complain about not having time for all the things I would like to do.
When I find some time I will get on with the monitor as that has now become a challenge.
One small advise I can give you on this...
Once you get over the threshold of fear when sticking your hands into the cars mechanics you will realize that it is a lot less complicated as your car mechanic is trying to make you believe (he will lose a customer obviously), but you can always go to a workshop if there is something they can do cheaper than you could as they do have some special tools.
As an example, in my car the fan has a contraption that makes the fan spin fast when the engine is hot.
To replace it myself it would mean to remove the radiator (cooling fluid first) than the airco radiators and part of the front bits.
Mercedes can replace this without removing more than the plastic shroud around the fan, so what would cost you about a day, they do in less than an hour and on top the wash you car.
See, that is where you can come back to the shop, but to repair anything electric and electronic in a car, you better do it yourself and there are great books about it available.
Anyway, let me know if you need a bit more encouraging..
Best regards,
Joseph.

[momaka]

Re: Proview LB 2006 W Monitor

Hi Joseph,
sorry I haven't been here for the last couple of days. It's been a somewhat rough week at school.

Anyways...

Yesterday night I had another short session and measured from the the pads to ground, R16 read 192 ohms to ground and R520 has 334 ohms to ground.
This is still no reason why I was measuring the 100 ohms but with the resistors and capacitors gone there is an infinite reading from the cathode of D10 to ground

Those readings seem okay. I'm guessing all of the ceramic capacitors you removed also show infinite resistance out of circuit (i.e. they are good). If not, let me know.

As soon as I find some time I will try to follow the tracks from these resistors

Try checking Q3 instead. See if there's a short between any of its terminals. Also measure resistance between all of its terminals and ground. Report back your results. My guess is Q3 is either "Q1" or "Q2" on the sample circuit in the datasheet (Page 20).
There's two more 3-terminal components above and below Q3. Can't tell if they are labeled D16 and D6 or Q16 and Q6. If labeled with Q (a transistor), check them the same way as Q3. If they are labeled with D, check them like you would a regular diode. Again, this is how they look internally if you need a reference:
https://www.badcaps.net/forum/attach...1&d=1294381123
Check D51 as well.

That's about all I can think of for right now. Actually, I have just a few more idea but would rather not suggest them unless we really run out of options, since there is a chance they may damage the t-con board.

....

Obviously I also spend some time on my car, a 20 year old Mercedes Benz 300D I bought just a few weeks before retiring and was meant as a hobby object (€1200.-).

Ahh, those old MBs are very nice. We used to have a 200 back in the late 90's for a few years (I was still a kid). It had 400-and-something thousand KMs when we got it. You couldn't tell though - the ride was as smooth as it probably was 20 years ago. And this thing actually did do 180 KM/h on the highway when my dad pushed it. Great car, really. Have fun with yours!

Also, thanks for the encouragement about fixing cars. Given that I'm not doing exactly great in school, though, I really need to focus more on that.

[Joseph67]

Re: Proview LB 2006 W Monitor

Hi Momaka,
I've been a bit busy with other things and as my space on the table is a bit limited by a lot of other junk sitting around to be looked at, I have to remove the monitor bits every time.
I hope to get on with it soon as I already mentioned that it would be a great monitor to use for watching films.
Obviously the first things will be follow up your suggestions and I'll report back ASAP.
Indeed, all the blasted capacitors that I removed are fine once removed.
Would be great to find the guilty one(s) and get the thing to work.
I remember my student times and I know there are some of these weeks that look as if there is no end to it.
Still I like to encourage you to keep up the good work at school as it will mean a decent job.
I see all around me people made redundant and having great difficulty to find a job as they are not really prepared for the actual work experience/levels.
Spanish government is offering many of then "re-schooling" so they might find work once "updated".
Mind you, I don't pretend to lecture you but just remember, you are studying for yourself and not for the teachers or your mum or dad, despite that sometimes you feel that way.
Our son has the same problems once in a while but reminding him that it is for him seems to encourage him for some time again.
I'll see you here again soon.
Best regards,
Joseph.

[starter28]

Re: Proview LB 2006 W Monitor

I welcome,
I am calling for help.
What value does C228 have?
The same display type: M201EW02 V.8
I am thanking for help.

[selldoor]

Re: Proview LB 2006 W Monitor

@starter 28
Hi= this Tcon has a different layout than that in the thread, is it out of the same make of monitor? Can we ask why you need to know -is it missing , shorted or what.
As you are new and have not posted the New members forum we have no idea of your level of knowledge. Are you aware that there is fuse/s on these boards and have you checked it/them.
I believe you will not get an answer to your question as this detail is rarely known most people seem to just try and find a cap the same size and shape and put that in. Finally perhaps you could update your profile with Country and Home Mains Voltage in case your post goes on.

[Joseph67]

Re: Proview LB 2006 W Monitor

Hi starter28,

With SMD components it is very hard to find out the value of capacitors and obviously not all that important.
It is like "selldoor" wrote, just look at the size and if it is shorted replace it with one of about the same size.
I have tried to get some info from Proview but they don't even reply.
I must assume that there are not that many "nuts" around who try to repair the Tcon board.
I think most just replace the whole monitor as prizes have come down quite a lot in the last years.
I was trying to repair it as a short of challenge and also since I am a pensioner I have to watch my budget a lot more that before.
As "Momaka" is still at school he might have more idea about the way of recognizing the modern-ish SMD components.
They are much newer/moderner than the ones we used I have been thought about at school in my time.
I had a teacher I remember who said about transistors that it was an funny experiment building things with transistors but they would never replace the vacuum tube.
I just wonder what he would say when seeing the latest integrated circuits circuit with all their build in functions.
Any way, just replace it with a C of the same size and you will be fine.
Cheers,
Joseph.

[starter28]

Re: Proview LB 2006 W Monitor

Yes, I exchanged C228 on 3 uF.
The monitor works.
Thanks
I am greeting

[Joseph67]

Re: Proview LB 2006 W Monitor

Good for you.
Cheers,
Joseph.

[momaka]

Re: Proview LB 2006 W Monitor

As "Momaka" is still at school he might have more idea about the way of recognizing the modern-ish SMD components.
They are much newer/moderner than the ones we used I have been thought about at school in my time.

Actually, they don't teach us anything like that in school - at least not in the college I go to. Most people in EE don't know how to tell SMD components apart (even graduates). The kits for our EE labs consist mostly of late 80's and early 90's components .

Yes, I exchanged C228 on 3 uF.
The monitor works.

Congrats!

[Joseph67]

Re: Proview LB 2006 W Monitor

Hi Momaka, That a shame. When I was at school we used the actual components like vacuum tubes (ECC83; EL84; etc...), "normal" resistors and electrolytic capacitors of 50uF/450VDC!!
I had to learn a lot afterwards in practice when one had to work with the newer stuff.
The "wounded monitor" is still waiting for new inspiration and time as I have been building in my house in Nicaragua for 6 months and just got back to Spain. First have to fix all things that went wrong when I was away and after that I am allowed to "play" with my toys again. I'll keep in touch. Best regards, Joseph.