WG 27 D9200 click click

[lilshawn]

I have a toasted WG D9200 monitor. Found dead and relay clicking over and over.

replaced the following faulty parts found....

CAPACITOR - C466 (swelled)
HOT - Q418 (shorted)
MOSFET - Q413 (shorted)
MOSFET - Q414 (open)
RESISTOR that runs off Q413 - R462 - (Burnt, 1ohm...reads in the kilo ohms)
RESISTOR - R804 (open)
DIODE - D424 (shorted)

checked the other resistors and diodes in the associated circuit area and they test okay. ran the cap analyzer over the rest of the bigger caps and they aren't terrible, but still what I would consider "okay for now"
heard around the grapevine that due to bad design, these chassis, when the HOT is blown, takes out a bunch of other stuff too. (as evident in the above list.)

But this chassis still won't boot up. Any other parts (or does anybody know what or where a list of the commonly killed components are/is)

EDITED TO ADD FAULTY PARTS

[grantspain]

http://www.wellsgardner.com/pdf/Repair/D9200_27_33_39_inch.pdf
i am sure ken mentioned that repair kits were provided by wg for these chassis

[lilshawn]

http://www.wellsgardner.com/pdf/Repair/D9200_27_33_39_inch.pdf
i am sure ken mentioned that repair kits were provided by wg for these chassis

there is?! what's up with that?

P.S. still broken.... work on it tomorrow

[lilshawn]

add to list: R804, had a hole blown open on the board side (didn't see it).

will source another tomorrow and see if it will start.

[lilshawn]

Email from WG regarding this unit:

Hello Shawn.
 
You are right about these units taking out multiple components but it seems like all of these multi-scan digital monitors have this trait. You seem to have covered all of the know components that usually go with this problem but there are a few additional ones that are overlooked. Make sure you check out R854 a 1.2 ohm 2 watt along with D424.
 
Like I said before these units the longer they burn in when they fail the more components seem to go, it’s like a domino effect. You may also have to change out IC404 and Q404 and any of the surrounding parts in that circuit.

[lilshawn]

still no luck as of yet. This chassis uses 3 SMPS PWM driver chips!!!! i'll have to pull them and check them.

[lilshawn]

removed all 3 SMPS driver IC's and still no start.

went over chassis again and checked diodes and resistors.

on startup the B+ voltage starts at 170+ volts then bleeds off to nothing

removed R854 to isolate that section from power supply and loaded with a lightbulb. power supply starts up and stays on.

[claysred]

Sounds like your power supply section is good.  With all the burned components in the 400 section, I'd think there must still be something fried in there.  Look at the schematic and see if you can isolate each section, one at a time.  Make sure you check IC401, IC403, Q401 and Q425.  Let us know what you find.

[lilshawn]

ya, removing r854 disconnects the entire 400 section (seems to be 3 different sections) i swapped the ic401 and q425 and tested q401 (still good). can't source the deflection processor (ic403) anybody know a quick and dirty test?

started isolating the specific sections.....

i disconnected the bd401, still won't start, hooked it back up and tried bd405, still nothing,

looking like the flyback may be the issue. i dont have another (at least i don't think so anyways) it's about the only thing left.

unless someone thinks that after disconnecting the bd's i have to load it with the bulb too? i would think there would be enough to properly load the power supply but you never know.

[lilshawn]

I have had a chance to get into testing a little more with this chassis. But still have not found the issue.

I have 170 volts (before it shuts down) getting to the drain of  q413 but nothing coming out of the source. But I have also found that there is nothing going into the gate of q413 to turn it on.

So going back through the circuit, I'm not getting anything out of pin 6 (the output of ic404) replacing it again does not help.

I tested for the presence of 20.5 volts at c458 and for 32 volts at zd403, both reading low (approx. 12 and 20 volts respectively)  and both varying up and down. SEE PIC FOR SCHEMATIC

just for giggles i tested the voltages at the neckboard (since there is a few right there) the 170 volts that goes to the neckboard is a solid 150   ... the 8 volt and 12 volt are pulsing with the clicking and the G2 voltage is non existent.   Why is this 170 solid, but the input down at R854 spikes up and bleeds off?!?!?!?

ARGH! stupid engineers! starting my voltage tracing over again tomorrow...starting with the 32 volt line

[lilshawn]

Disconnected the R854 and loaded with a lightbulb. Power supply works properly this way.

170 volts = 170v
12 volts = 11.8v
8 volts = 8.0v
32 volts = 32.19v (as measured from input side of zd403)
20.5 volts = 21.7v (feed to IC404)
TP14 (output of IC404) = 20.3v
TP 17 (output of q413) = 0.2v
R461 (feeds gate of Q413) = 4.00v

replaced Q413 already, and a quick and dirty test of it shows still okay. the FET should be turning on since it has 4 volts feeding the gate but nothing is flowing. Quick and dirty test gets the FET to turn on and begin conducting at about 2 volts so i'm still not sure what the heck is going on.

BTW: "quick and dirty N channel FET test":

1:) Place FET in front of you tab/mounting hole on top legs sticking out the bottom. this ensures GDS (Gate Drain Source) leg configuration. if testing smaller "TO-92" FETs be aware that the leg configuration is SGD (when viewing the writing on the flat side)
2:) set volt meter set to "diode test"
3:) Place red lead on center leg (drain)
4:) place black lead on right leg (source)
5:) meter should read a no voltage condition.
6:) place your finger between the first and second leg (gate to drain) hold for a few seconds then remove.
7:) meter should read some voltage conducting through the FET. maybe about 2 volts
8:) reversing the red/black leads should show about .4 to .5 volts (the meter is showing the forward voltage of the intrinsic diode of the FET)

if the FET does not conduct (open) or shows a 0 volt drop (shorted) the FET is bad if the forward voltage is below about .4 volts, the FET is likely bad. if it's below .3 it's very likely bad.

[claysred]

Found anything else fried?

[lilshawn]

sadly no... John Pruski with whom i was conversing with regarding this chassis has gone on vacation till next week... and probably missed my last e-mail before taking off 

i'll post up the e-mails i have regarding this situation thus far... begin reading from the bottom up

Out of Office AutoReply: d9200 issue‏
From:    John Pruski (jpruski@wellsgardner.com)
Sent:   May 13, 2010 3:45:11 PM
To:   Shawn Abernethy (lilshawn2@hotmail.com)
I will be out of the office from Friday,May 14th thru Monday, May 24th. I will be back on Tuesday, May 25th.


-----Original Message-----
From: lilshawn2@hotmail.com
Date: Thu, 13 May 2010 21:46:18
To: John Pruski<jpruski@wellsgardner.com>
Subject: Re: d9200 issue

No, only schematic list part #'s where used as replacements. I only go NTC for discontinued parts.

I booted up the board (after soldering back r462) and let it TRY to run for 60 seconds. Non-contact infrared thermometer shows absolutely no increase in temperature whatsoever in either of those components during the time it was on. (21.4 c before and 21.4c after)

I also checked the temperature of q413, which rose slightly (0.6 degrees during that time)

I let the unit continue to run for another 60 seconds, and observed no significant changes (within scanning error) in either q425 or q418 and a total change of 1.8 degrees in q413 over the duration of the test.

I felt no further testing was necessary. (Don't want to kill anything else either)


Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: John Pruski <jpruski@wellsgardner.com>
Date: Thu, 13 May 2010 19:59:07
To: <lilshawn2@hotmail.com>
Subject: RE: d9200 issue

Shawn, one more thing when the unit is on are the Q425 and Q418 running extremely hot. And also make sure you use only OEM parts because if you use NTE parts they can give you more problems.

-----Original Message-----
From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Thursday, May 13, 2010 2:48 PM
To: John Pruski
Subject: Re: d9200 issue

Still no start, volts start @ 180v then bleed down to about 149v (varying ±2v ) after about 10 seconds.
Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: John Pruski <jpruski@wellsgardner.com>
Date: Thu, 13 May 2010 18:11:40
To: <lilshawn2@hotmail.com>
Subject: RE: d9200 issue

Shawn thanks for all effort you have put into this monitor but let's try one more little trick to see if we can find the problem. Put the R854 back into circuit and this time remove lift R462 out of the circuit and then re-check the 170vdc. If the 170 is ok than the problem is most likely the flyback transformer.

-----Original Message-----
From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Thursday, May 13, 2010 9:55 AM
To: John Pruski
Subject: Re: d9200 issue

Forgive the lateness of my reply, duty calls when a transformer blows up across town!

I disconnected the resistor ( I also loaded the 170 line with a lightbulb) here is the voltages I read:

170 = 170
12 = 11.8
8 = 8.0
32 = 32.19 (as measured from the entrance side from zd403)
32 = 32.19 (as measured from R835 on output of power supply)
20.5 (feed to ic404) = 21.7
TP14(output of ic404) = 20.3
TP17 (output of Q413) = 0.2
R461 (feeds the gate of Q413) = 4.00

Replaced already, a quick and dirty check of Q413 shows still okay.

Still confused,
Shawn


Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: John Pruski <jpruski@wellsgardner.com>
Date: Wed, 12 May 2010 14:10:43
To: <lilshawn2@hotmail.com>
Subject: RE: d9200 issue

Shawn, I hate to let this chassis win over us. Lets remove R854 out of the circuit and re-measure the voltage off the power supply especially 170 and 32volts along with the 12volts.

-----Original Message-----
From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Wednesday, May 12, 2010 9:05 AM
To: John Pruski
Subject: Re: d9200 issue

The only voltage that's stable is the 170 which is at 150 volts +/- 1 volt . The 8 and 12 are pulsing (below 5 volts) with the relay clicking. G1 is nearly nonexistent. I tested those voltages with the neck board plugged in. When the connector is unplugged, the voltage at the connector for 170 volts is 160. all the other voltages behave the same (pulsing).


Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: John Pruski <jpruski@wellsgardner.com>
Date: Tue, 11 May 2010 15:50:01
To: <lilshawn2@hotmail.com>
Subject: RE: d9200 issue

Shawn

  Let's try to check the voltages off of the power supply that are at the Neck Board there is a connector that you can easily check the 12v and the 8v along with the G1 voltage which is usually a negative 50v.   

-----Original Message-----
From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Tuesday, May 11, 2010 9:59 AM
To: John Pruski
Subject: d9200 issue

I have had a chance to get into testing a little more with this chassis. But still have not found the issue.

I have 170 volts (before it shuts down) getting to the drain of  q413 but nothing coming out of the source. But I have also found that there is nothing going into the gate of q413 to turn it on.

So going back through the circuit, I'm not getting anything out of pin 6 (the output of ic404) replacing it again does not help.

I tested for the presence of 20.5 volts at c458 and for 32 volts at zd403, both reading low (approx. 11 and 20 volts respectively)  and both varying up and down.

Sorry to be such a bother, but if you have any suggestions, I'd be willing to entertain them.

Thank you for your help

Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: lilshawn2@hotmail.com
Date: Mon, 10 May 2010 18:22:00
To: John Pruski<jpruski@wellsgardner.com>
Subject: Re: d9200 issue

Good afternoon,

Q425 tests okay. No 170 voltage at R462. Issue must be upstream then. Switched out ic404 already, but you never know now a days.
Sent from my BlackBerry device on the Rogers Wireless Network

-----Original Message-----
From: John Pruski <jpruski@wellsgardner.com>
Date: Mon, 10 May 2010 15:45:21
To: <lilshawn2@hotmail.com>
Subject: RE: d9200 issue

Hello Shawn.
 
It looks like you have one of those though ones. It might be a possibility that you have a bad flyback  so lets see if Q425 is ok or not and also check out to see if you have the 170vdc at R462.
 

From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Monday, May 10, 2010 9:57 AM
To: John Pruski
Subject: RE: d9200 issue
 
i'm still having issues with this chassis. i have replaced the parts you suggested, and tested several others. i have also replaced a few resistors that looked a little suspect but tested okay. (darker burned color)

 

on startup the B+ voltage starts at 170+ volts then bleeds off to near nothing. a chassis solenoid clicks. removed R854 to isolate that section from power supply and loaded with a lightbulb. power supply starts up and stays on. feel the issue is in the "400" section.

 

i removed the ferrite beads that feed a few sections (i disconnected the bd401, still won't start, hooked it back up and tried bd405, still nothing) so i'm still unable to isolate where the issue is.

 

I went through the 400 section and tested all the transistors and checked diodes but to no avail.

just wondering if you can suggest anything else i could try.

 

----------------

From: lilshawn2@hotmail.com
To: jpruski@wellsgardner.com
Subject: RE: d9200 issue
Date: Tue, 4 May 2010 08:46:54 -0600

thank you for your prompt reply,

 

"R854 a 1.2 ohm 2 watt "

 
The schematic sheet calls for a 1 watt resistor, should I up this to 2 watts or leave it as 1 watt?

 

Hello Shawn.
 
You are right about these units taking out multiple components but it seems like all of these multi-scan digital monitors have this trait. You seem to have covered all of the know components that usually go with this problem but there are a few additional ones that are overlooked. Make sure you check out R854 a 1.2 ohm 2 watt along with D424.
 
Like I said before these units the longer they burn in when they fail the more components seem to go, it's like a domino effect. You may also have to change out IC404 and Q404 and any of the surrounding parts in that circuit.
 


From: Shawn Abernethy [mailto:lilshawn2@hotmail.com]
Sent: Monday, May 03, 2010 3:55 PM
To: John Pruski
Subject: d9200 issue
 
I have a toasted WG D9200 monitor. Found dead and relay clicking.

found and replaced the following faulty parts...

CAPACITOR - C466 (swelled)
HOT - Q418 (shorted)
MOSFET - Q413 (shorted)
MOSFET - Q414 (open)
RESISTOR that runs off Q413 - R462 - (Burnt, supposed to be 1ohm...read in the kilo ohms)

checked the other resistors and diodes in the associated circuit area and they test okay. ran the cap analyzer over the rest of the bigger caps and they aren't terrible, but still what I would consider okay. I checked through the WG supplied troubleshooting chart as well.


I heard around the internet that due to bad design, with these chassis, when the HOT is blown, takes out a bunch of other stuff too. (as evident in the above list.) But this chassis still won't boot up. Any other parts (or does anybody know what or where a list of the commonly killed components are/is when the HOT blows.)

I also heard there is a fix for this chassis to prevent something like this from happening again, is this true or is someone just blowing smoke?

 

any info would be greatly appreciated. 

 

thank you for your time.

[lilshawn]

 

still no word yet with regards to this chassis. perhaps it's a lost cause.... *sigh* sending another e-mail.

[grantspain]

why do i have a feeling that John may have been very busy helping with d9200 faults this week

[lilshawn]

yeeeaaaaaaa  ....could have a little something to do with this: http://forum.arcadecontrols.com/index.php?topic=103017.0   

[Madman]

Did you ever solve your issue? I seem to have a similar problem

[lilshawn]

PM sent...

I have back burnered this monitor project for now...and seeing since this monitor is for work, it was just more cost effective for us to replace the monitor and be done with it.

I have a feeling that maybe the flyback has been toasted. (seemed to be the only thing left) I had another tech from another company take a look at it, and even he was mystified by my notes and readings...

if it comes down to us really needing it to fix something, I will re-visit it then.