This is a monitor that I bought at the Computer Recyclers Center where I live
for $20.00 US
Attached Files
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
< Please and Thanks for any help that you can give me
I have power the board with a 12 volt power supply and can get the evey thing to work but it will not power on with the power cord
I had remove the yellow tranformer when using the 12 volt power supply
I am real as what to do next
Any idea what to check next I have replaced the mosfet and still no go
The Cap near the yellow tranformer has a voltage about 160 volts DC
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
< Please and Thanks for any help that you can give me
I have power the board with a 12 volt power supply and can get the evey thing to work but it will not power on with the power cord
I had remove the yellow tranformer when using the 12 volt power supply
I am real as what to do next
Any idea what to check next I have replaced the mosfet and still no go
The Cap near the yellow tranformer has a voltage about 160 volts DC
To repair monitors in a cost effective manner you must not arbitrarily replace components unless you have a good reason to believe they are defective.
In case of a 'Dead' problem, the first step should be to measure the output voltage of the power supply. If this is 0 volts, the second step is to measure the voltage across the large cap. 'About 160 volts' is interesting for a number of reasons. It is approximately correct, if slightly low. Is it steady, or does it vary? Are you measuring with a DMM?
If the output is 0 volts, but the voltage across the large cap is correct, the next step is to check the SMPS controller. What is the part number on U850? What is the voltage on Vcc?
PlainBill
For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.
Here is the Data Sheet for U850 <
Here is the Part # for U850 <..> SG5841SZ
How do check U850
I had check the Q850 which is a mofet on both boards with a meter and got two very different reading on each one so did not know which one was bad or either one was good and the cost of each one was about $2.00 each on Ebay
I check to see if the gate on Q850 had any voltage which it did about 14 volts DC
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
"About 160 volts' is interesting for a number of reasons. It is approximately correct, if slightly low. Is it steady, or does it vary? Are you measuring with a DMM?"
For most part it steady
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
I will give you those reading a little later on today
If I have to replace this chip what is the best way to remove the old one and solder in the new one I have not solder ( 8-Pin Small Outline Package (SOP) type before
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
I will give you those reading a little later on today
If I have to replace this chip what is the best way to remove the old one and solder in the new one I have not solder ( 8-Pin Small Outline Package (SOP) type before
ChipQuik makes removal easy. Clean up the residue using solder braid. Soldering is covered in this video.
PlainBill
For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.
Both pin 3 and 7 have a voltage between 12 and 14.5 volts DC trying to turn on the monitor make no difference
The measurement across the large cap is a steady 166.7 volts DC
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
I made a mistake in this post it is not a E1703 it is a E1706 sorry about this
I have both model
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
Both pin 3 and 7 have a voltage between 12 and 14.5 volts DC trying to turn on the monitor make no difference
The measurement across the large cap is a steady 166.7 volts DC
Not nearly good enough. Let me explain. I do not have the monitor here. I cannot see what readings you are getting. If you are unwilling or unable to give me specific information, you might as well go back to changing parts at random.
Pin 3 is the startup input. It is connected to the +166 volt supply by a large value resistor. Pin 7 is Vdd - the supply voltage for the IC There is a startup cap from pin 7 to ground. When the monitor is plugged into AC power the startup cap is charged until Vdd reaches 16 volts. At that point the SMPS controller starts, and provides it's own run power.
The voltage on each pin, and the characteristics are critical. If the voltage at pin 7 is jumping around it indicate one problem. If it is steady, it indicates another. If the voltage at pin 3 is too low, it indicates something else.
PlainBill
For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.
"If the voltage at pin 7 is jumping around it indicate one problem." <... YES
between 12 and 14.5 volts
" If it is steady, it indicates another." <...... NO
" If the voltage at pin 3 is too low, it indicates something else." <.... The voltage is the same between 12 and 14.5 volts What should this voltage be ??
" If you are unwilling or unable to give me specific information, < ... This is NOT the case these are the reading that I am getting
" you might as well go back to changing parts at random." <........ I really do not want this way
I am trying to give you the messurement that you are asking for
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
" Pin 3 is the startup input"......> "There is a startup cap from pin 7 to ground. When the monitor is plugged into AC power the startup cap is charged until Vdd reaches 16 volts."
It never reaches 16 volts on either pin 3 or pin 7 so what do I need to need to check
I do have cap tester how ever I will need to remove the cap to test them
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
" Pin 3 is the startup input"......> "There is a startup cap from pin 7 to ground. When the monitor is plugged into AC power the startup cap is charged until Vdd reaches 16 volts."
It never reaches 16 volts on either pin 3 or pin 7 so what do I need to need to check
I do have cap tester how ever I will need to remove the cap to test them
You need to let which ones I need to check
The key is the voltage jumping. It is likely that the startup cap is bad. Another possibility is that the SMPS controller is bad. A third possibility is that one of the outputs is shorted, but that is much less likely.
I'd suggest starting by checking the diodes on the output of the SMPS transformer. Since you got the monitor working using an external supply, we know there is no problem with a short on the load. Next, try replacing the startup cap with a known good one and seeing if that fixes the problem. If the output diodes were not shorted, and replacing the startup cap doesn't fix it, you have a bad smps controller. DigiKey doesn't carry them, but they are available on eBay.
PlainBill
For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.
I have only seen this Board on the Dell FPf series of Monitor, and the SMPS controller is known to fail on a regular basis,so looks like you are on the right track.
I have only seen this Board on the Dell FPf series of Monitor, and the SMPS controller is known to fail on a regular basis,so looks like you are on the right track.
Unfortunately for 3sam, the controller is not available from DigiKey. Fortunately he can buy 5 for $10 (including shipping) from eBay sellers in China.
Unfortunately for 3sam, the controller is not available from DigiKey. Fortunately he can buy 5 for $10 (including shipping) from eBay sellers in China.
PlainBill
Thats where I purchase mine from,and they are used quite regularly.
The key is the voltage jumping. It is likely that the start-up cap is bad. Another possibility is that the SMPS controller is bad.
I'd suggest starting by checking the diodes on the output of the SMPS you have a bad smps controller. PlainBill
I found the part at Mouser 512-SG5841JSZ .....> SG5841SZ
I put it in today and it came back to LIFE the only problem now is to get a set of CLF tubes that are good to finish this repair
I can only hope .....>
___________________________________________________________
The reason I do not a good set of CLF tubes I have three monitors that have the same model # and one them the boards worked but one of the CLF was bad on the other monitor had one CLF that did not work but the other one did not and only one that both sets of CLF tube
I did not care about this at the time, because I only had ONE board that work
The Last Board has some real Problem with it one of the resistor that is real tiny rear the U850 is OPEN also there is a problem
with U851 or with U801 or with U802 it work BUT I had to use two power supplys to get it to come on BUT I do not think I want to spend the time on this board I will just CUT the invert board part off of it and use it to check CLF tube with it
PlainBill
I WANT to THANK YOU for all of your help in this matter and helping get this monitor working again I wish I could send you a
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *
These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%
1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board
All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
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