HannStar Monitor

[rigeback]

Re: HannStar Monitor

Hi Momaka, thanks for the instructions although its nots so easy to comprehend for someone who has never done it before, anyhow took some more readings and you right about the 200 setting that worked for some of the caps.
I take that at this setting of 200 when I get a reading of 00.6 I've got 0.6 Ohms, right? That means I've got a bunch of low readings!
Anyhow ZZ1 is 00.6, C513 is 00.7, C515 is 10.8, C518 is 00.5 (the Big cap) C13 is 0.502 @2k.
Happy halloween and the home work, are you studying electronics?
C523, C524, C505 and C508 and a few more no reading 200 or 2K tester reads 1??

[momaka]

Re: HannStar Monitor

Hi Momaka, thanks for the instructions although its nots so easy to comprehend for someone who has never done it before,

Hi rigeback, sorry if the instructions were a bit confusing. It was pretty late when I typed them last night. Now that I re-read them again, they sound a bit rough with that bald text as if I'm screaming - sorry if you thought they came out that way.

Anyways, back on topic...

anyhow took some more readings and you right about the 200 setting that worked for some of the caps.
I take that at this setting of 200 when I get a reading of 00.6 I've got 0.6 Ohms, right? That means I've got a bunch of low readings!

Correct

C523, C524, C505 and C508 and a few more no reading 200 or 2K tester reads 1??

If the "1" is on the left side of the screen of the multimeter, then those capacitors are fine. The "1" on the left side means that the resistance is higher than 200 Ohms (if you're using the 200 Ohm scale) or higher than 2k (if you're using the 2kOhm scale).
We are interested only in the low resistances, so in this circuit, any capacitor that shows above 100 Ohms can be regarded as good.

Anyhow ZZ1 is 00.6, C513 is 00.7, C515 is 10.8, C518 is 00.5 (the Big cap) C13 is 0.502 @2k.

Except for C13, those other readings are very low. Sorry if I'm asking redundant questions here, but were you checking each of these capacitors accross (that is, one probe on one side and the other probe on the other side of the capacitor)? - If yes, then we have a lot of problems. In that case, start removing those capacitors from the t-con one by one and test them with your multimeter out of circuit. Do they show the same low readings out of circuit on the 200 Ohm scale?

Happy halloween and the home work, are you studying electronics?

Thanks . Happy Halloween to you as well! (if you are celebrating)
Yes, I'm studying eletronics, but I'm learning more from this forum and from the things I fix than at school .

[rigeback]

Re: HannStar Monitor

[QUOTE]: No worries I use to train people and would frustrated as hell some times=momaka;193639]Hi rigeback, sorry if the instructions were a bit confusing. It was pretty late when I typed them last night. Now that I re-read them again, they sound a bit rough with that bald text as if I'm screaming - sorry if you thought they came out that way.

Anyways, back on topic...

Correct


If the "1" is on the left side of the screen of the multimeter, then those capacitors are fine. The "1" on the left side means that the resistance is higher than 200 Ohms (if you're using the 200 Ohm scale) or higher than 2k (if you're using the 2kOhm scale).
We are interested only in the low resistances, so in this circuit, any capacitor that shows above 100 Ohms can be regarded as good.

:No thats okay I did check each cap across although I just noticed in your quote its not C13 but C37, sorry about that, one thing with C37 it tests .509 one way and 1.245 opposite! Except for C13, those other readings are very low. Sorry if I'm asking redundant questions here, but were you checking each of these capacitors accross (that is, one probe on one side and the other probe on the other side of the capacitor)? - If yes, then we have a lot of problems. In that case, start removing those capacitors from the t-con one by one and test them with your multimeter out of circuit. Do they show the same low readings out of circuit on the 200 Ohm scale?


Thanks . Happy Halloween to you as well! (if you are celebrating)
Yes, I'm studying eletronics, but I'm learning more from this forum and from the things I fix than at school .

[QUOTE]:No I'm just taking easy this time round.

[rigeback]

Re: HannStar Monitor

I just noticed in your quote its not C13 but C37, sorry about that, one thing with C37 it tests .509 one way and 1.245 opposite!
As you can see I need some practice writing QUOTES!!

[rigeback]

Re: HannStar Monitor

I removed C513 and tried to test it but no reading even at 200K and no contenuity! How should I go about testing these caps off board? So far only C513 off board to determin its condition.

[rigeback]

Re: HannStar Monitor

one other thing when probing both sides of the board where C513 was soldered both pads give contenuity to ground???

[momaka]

Re: HannStar Monitor

I just noticed in your quote its not C13 but C37, sorry about that, one thing with C37 it tests .509 one way and 1.245 opposite!

Yeah, that's usually normal. The reason behind the different readings is because there are diodes in the circuit, and those will read higher resistance/continuity in one direction than in the other.

I removed C513 and tried to test it but no reading even at 200K and no contenuity!

That means C513 is fine.
Outside the circuit, capacitor are indeed supposed to show open-circuit (no continuity at all).

How should I go about testing these caps off board? So far only C513 off board to determin its condition.

Resistance check, just like you were doing it in circuit.
First try 200 Ohm scale... if you get open circuit, go to 2 kOhm scale... if you get open circuit, then the capacitor is more than likely fine and you can put it back in the circuit.

one other thing when probing both sides of the board where C513 was soldered both pads give contenuity to ground???

Low continuity?... How much?
What about resistance - do you get less than 10 Ohms to ground on both sides? If yes, then that's exactly the type of problem we are looking for.

As you can see I need some practice writing QUOTES!!

It's easy. Just type
[*quote* = "name_of_the_person_you're_quoting"]*and place the person's quote here*[*/quote*]
Ignore all of the " * " symbols I put above, though - I only put those there so that the forum will not interpret it as a quote so that you can see the syntax.

[retiredcaps]

Re: HannStar Monitor

Low continuity?... How much?

Multimeter have no standard for the continuity threshold. For example, one Fluke multimeter might beep continuity for resistance less than 30 ohms. Another brand I have seen beeps continuity for resistance less than 700 ohms.

[rigeback]

Re: HannStar Monitor

Yep its real low 00.8 from both pads to various areas on the board, the only cap that gave a bit more 10.8 was C515.
What do you sugest replace C513 or pop a few of the others??

[jetadm123]

Re: HannStar Monitor

Yep its real low 00.8 from both pads to various areas on the board, the only cap that gave a bit more 10.8 was C515.
What do you sugest replace C513 or pop a few of the others??

I would suggest you remove C513 from the board and remeasure it's resistance. If it still shows shorted, then replace it.

[momaka]

Re: HannStar Monitor

Multimeter have no standard for the continuity threshold.

Yes, but they do show the voltage drop.

Yep its real low 00.8 from both pads to various areas on the board, the only cap that gave a bit more 10.8 was C515.
What do you sugest replace C513 or pop a few of the others??

Well, if both pads where C513 was show short-circuit to ground, then C513 is likely in parallel with other ceramic capacitors.
The next task is to find all ceramic capacitors that show the same low-reading to ground on both sides. Let me know which ones you find to be like that.

As for C513, you said you measured it at 200k and it still showed no reading (open-circuit), so that means C513 is okay. Save it for right now. You can put it back in the circuit later once we find the faulty component.

[rigeback]

Re: HannStar Monitor

Okay, new tests to ground indicate that most of the "C" caps are okay, however 7 of the "R" caps / diodes test .500 both ways, these are the small black caps with (000) or (010) markings?
ZZ1 is also .500 both ways and L1/2/3 check 1.140 both ways and C1 is .000 both ways.
All tests were done at 2K, the black caps mostly indicate through contenuity!

[PlainBill]

Re: HannStar Monitor

Okay, new tests to ground indicate that most of the "C" caps are okay, however 7 of the "R" caps / diodes test .500 both ways, these are the small black caps with (000) or (010) markings?
ZZ1 is also .500 both ways and L1/2/3 check 1.140 both ways and C1 is .000 both ways.
All tests were done at 2K, the black caps mostly indicate through contenuity!

I've been stayong out of this thread, momaka has been doing much better than I could, but I saw something that really needs correction. This post indicates one of the reasons there has been so many difficulties troubleshooting.

A component whose identifier starts with an R is a resistor, not a capacitor. an identifier that starts with C is a capacitor, D is for Diode, Q for Transistor, L for inductor. I've marked up some or them on the picture.

I wasn't able to locate C1, but that reading indicates it is a prime suspect.

PlainBill

[rigeback]

Re: HannStar Monitor

Bill thanks for the help outlining them items on the picture, that really makes a lot more easy to understand, I guess I miss the point here without realizing it, yes C1 in this case will be a main suspect.

[momaka]

Re: HannStar Monitor

Thanks for the explanation PlainBill. Makes it much easier for me to explain as well .

@rigeback:
yes, remove C1, and test out of circuit.

[rigeback]

Re: HannStar Monitor

Well it turns out that I retested C1 and got a reading 1.145 /.000 and C15 next door gives the same so I left them alone.
Anyways I checked the group of caps C507, C508 and C509 and they had some low values 1. /.000 so I removed C509 but its real confusing how to determin whats shorted as there is no reading across even on 2M and no conteuity so I'm lost for ideas now??
C510 has a slightly different reading to the other caps in the group 1.872 but probably OK I guess!

[retiredcaps]

Re: HannStar Monitor

but its real confusing how to determin whats shorted as there is no reading across even on 2M and no conteuity

I have been reading along and suggest you consider the following. With respect, I think you misunderstand how to use a multimeter and what we are asking for when looking for a shorted component.

1) A multimeter always gives a reading. "1" on the left hand side of the display means the reading is "out of range". 1.0 on the right side on the display is a unit of measure (i.e. 1 unit of measure). As you as you turn on the multimeter, it gives you a reading. There is no such thing as "no reading".

2) When testing for a short, put your multimeter on 200 (two hundred) ohms. Any reading under 30 ohms suggests a short. If your multimeter reads "1" on the left hand side, it is telling you that the resistance is greater than 200 ohms (out of range for the dial setting). At this point, we don't care what the actual resistance reading is. We know it is NOT less than 30 ohms and thus it is NOT shorted.

So testing for a short on the 2K, 20K, or 2M dial setting is pointless. In fact, testing for a short on the 2M can lead to misdiagnosis.

3) For beginners, using an autoranging multimeter is much easier. You don't have to worry about dial settings, etc.

4) When reporting measurments, we need to know what you have recorded. 1.0 means nothing. Is it 1.0 ohms, 1.0V DC, 1.0V AC, 1.0uF, etc?

[retiredcaps]

Re: HannStar Monitor

5) If you think your multimeter is not working when reading resistance, do a real simple test. Put your multimeter on 200 ohms and touch your probes together. It should read less than 1.0 ohms. Any reading above 1.0 ohms when your probes are touching suggests a bad/weak battery or your test leads are worn (wires inside are fraying).

[rigeback]

Re: HannStar Monitor

I appologize for not indicating 1.145 Ohms I was taking it for granted I guess that any one reading would understand but you're right.
Thing is with this T-con when testing with the 200 Ohms setting it gives an overall "1" and 00.5 reading when testing the caps, so I don't think if I will ever find the short to get it going!

[rigeback]

Re: HannStar Monitor

5) If you think your multimeter is not working when reading resistance, do a real simple test. Put your multimeter on 200 ohms and touch your probes together. It should read less than 1.0 ohms. Any reading above 1.0 ohms when your probes are touching suggests a bad/weak battery or your test leads are worn (wires inside are fraying).

Thanks for that information and I have just checked my multimeter as you said and it reads 00.5 Ohms which suggests its okay.