Kortek 3414df Chassis Troubleshooting - Power Supply Voltages

cwstrong

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Kortek 3414df Chassis Troubleshooting - Power Supply Voltages

I've been troubleshooting this chassis for the past couple of weekends, but I'm getting nowhere fast. It's time to ask for some assistance from the group. I've read the Kortek Monitors Tips,Tricks and Cap Kits thread, but I'm still stuck.

Symptoms:
Chassis is completely dead although 120vac is present. A full cap kit has been completed, but I don't appear to be getting any VDC in the secondary. The fuse at F101 is not blown and IC103 has been replaced. The bridge rectifier at D120 also tests good and has an output of 160vdc. I'm using the negative terminal of the filter cap at C114 for the hot ground. There is no visible damage to the board or any components.

The service manual states to check for 80vdc on D110. I have zero volts being output from SMPS (T101), although 160vdc is present on 2 of the 4 pins on the primary side. The other 2 pins appear to be grounded.

Any suggestions on what to check next? I have the 3414df schematic, but determining what voltage should be present where is still somewhat confusing.

Thanks in advance for any assistance or at least a push in another direction.
 
This thread has been moved to Kortek Monitors Tips,Tricks and Cap Kits.

https://forums.arcade-museum.com/showthread.php?t=157123


We can use this thread.

Need to see if the ic you replace gets warm at all?

Lift one end of R115,R112, and R116

Measure the ohms are good around the IC.

If no secondary voltages, you should check all or most of the

secondary's voltages, not just one voltage.

Watch out for the bad connections under the glue

around the board.
 
Kortek 3414df Chassis Troubleshooting - Power Supply Voltages

We can use this thread.

Need to see if the ic you replace gets warm at all?

Lift one end of R115,R112, and R116

Measure the ohms are good around the IC.

If no secondary voltages, you should check all or most of the

secondary's voltages, not just one voltage.

Watch out for the bad connections under the glue

around the board.

Thanks for the help!

The heat sink for IC103 remains cold when AC is applied.

I've metered each of the specified resistors with a leg up and all checked out.

R112 = 198.7K ohms
R115 = 198.5K ohms
R116 = 5.0 ohms

I've also metered across the chassis and do not appear to be getting any secondary DC voltages.

On a side note, are you familiar with this chassis having an added jumper wire running in series between C602 (-) to C711 (+)? Another 3414DF I capped in the past did not have this jumper wire.

Thanks again.
 
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Ok you eliminated that, but you should test the vcc for voltage?

other voltage pins will help to decide if the ic is running, but no voltages posted

a o-scope will tell ya if its working or off frequency,

If good voltage, put the old one back.

may have a bad new one, just a guess..

Any faint ticking coming from the smps??

I believe Your good on the c602 and c711

Anyway they won't stop the voltage in the secondary.

Did you read about the smps traces around the smps I mention on these models

and glue causing bad connection?

It doesn't stand out, it may not even look bad,

at the pins of the smps scrape up the trace and reflow with solder

confirming a better connection just a little about a half and inch..

to and from the pin.

Just need to eliminate the connections from my experience with these models.
 
Kortek 3414df Chassis Troubleshooting - Power Supply Voltages

Ok you eliminated that, but you should test the vcc for voltage?

other voltage pins will help to decide if the ic is running, but no voltages posted

a o-scope will tell ya if its working or off frequency,

If good voltage, put the old one back.

may have a bad new one, just a guess..

Any faint ticking coming from the smps??

I believe Your good on the c602 and c711

Anyway they won't stop the voltage in the secondary.

Did you read about the smps traces around the smps I mention on these models

and glue causing bad connection?

It doesn't stand out, it may not even look bad,

at the pins of the smps scrape up the trace and reflow with solder

confirming a better connection just a little about a half and inch..

to and from the pin.

Just need to eliminate the connections from my experience with these models.

IC103 readings:

Pin 1 = 0
Pin 2 = 0
Pin 3 = 1.3v
Pin 4 = 0
Pin 5 = 158v

I have extended and reflowed all smps pins and traces.

There is no audible ticking when the chassis is powered up. It's completely silent.

There is minimal glue on this chassis. I do not see any glue covering traces, components or connections.
 
IC103 readings:

Pin 1 = 0
Pin 2 = 0
Pin 3 = 1.3v
Pin 4 = 0
Pin 5 = 158v

I have extended and reflowed all smps pins and traces.

There is no audible ticking when the chassis is powered up. It's completely silent.

There is minimal glue on this chassis. I do not see any glue covering traces, components or connections.

You got the pins mixed up.

but I know what you mean. Pin 1 should have the 158v on it.

vcc should have a higher dc.. but,

Need to check R119 and D118 but should be good if you have voltage on pin 8

of Ic 104, Q102 would not be a suspect if you have 160vs dc on the drain

Just missing PWM for Mosfet , see if warm after 5 minutes.

May need Ic104 if no drive check the pin 7 ?
 
You got the pins mixed up.

but I know what you mean. Pin 1 should have the 158v on it.

vcc should have a higher dc.. but,

Need to check R119 and D118 but should be good if you have voltage on pin 8

of Ic 104, Q102 would not be a suspect if you have 160vs dc on the drain

Just missing PWM for Mosfet , see if warm after 5 minutes.

May need Ic104 if no drive check the pin 7 ?

Actually, there are no components located at R119, D118 and IC104 on the 3414 chassis.

What Mosfet are you referring to in regards to PWM...Q713? I did apply power to the chassis for 5 minutes, but didn't notice the warming of any heat sinks.

I just discovered that there is a "very" faint ticking sound coming from the SMPS. It's barely noticeable, it's so quiet. Do you recommend that I replace Q712 (with upgrade) and Q713?

Thanks again for your assistance!
 
Actually, there are no components located at R119, D118 and IC104 on the 3414 chassis.

What Mosfet are you referring to in regards to PWM...Q713? I did apply power to the chassis for 5 minutes, but didn't notice the warming of any heat sinks.

I just discovered that there is a "very" faint ticking sound coming from the SMPS. It's barely noticeable, it's so quiet. Do you recommend that I replace Q712 (with upgrade) and Q713?

Thanks again for your assistance!

http://www.arcade-museum.com/manuals-monitors/Kortek KT_3414DF1.pdf

I see it on the manual.

you have a different model?

The 80 volt line needs to be test for a short Lift a leg of L601

to input of flyback, power back up need to know if the 80vs and other are present?



Q712 is for scan output to drive just the horizontal windings on the yoke

not High voltage that's q603 through the flyback.

You will get a faint ticking if the PS if off frequency and being shutdown

or bad new part.

Check it out.
 
http://www.arcade-museum.com/manuals-monitors/Kortek KT_3414DF1.pdf

I see it on the manual.

you have a different model?

The 80 volt line needs to be test for a short Lift a leg of L601

to input of flyback, power back up need to know if the 80vs and other are present?



Q712 is for scan output to drive just the horizontal windings on the yoke

not High voltage that's q603 through the flyback.

You will get a faint ticking if the PS if off frequency and being shutdown

or bad new part.

Check it out.

http://www.arcade-museum.com/manuals-monitors/Kortek KT_3414DF1.pdf

I see it on the manual.

you have a different model?

The 80 volt line needs to be test for a short Lift a leg of L601

to input of flyback, power back up need to know if the 80vs and other are present?



Q712 is for scan output to drive just the horizontal windings on the yoke

not High voltage that's q603 through the flyback.

You will get a faint ticking if the PS if off frequency and being shutdown

or bad new part.

Check it out.

The model number on the neckboard is kt-3414df. I've included an image of the primary area where R119, D118 and IC104 do not exist.

I lifted a leg on L601 and confirmed there is still no 80v or other vdc present.
 

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The model number on the neckboard is kt-3414df. I've included an image of the primary area where R119, D118 and IC104 do not exist.

I lifted a leg on L601 and confirmed there is still no 80v or other vdc present.


Ok, no 80vs what about the rest of the secondary voltages??

The Power Ic has then PWM in it.

that would be the circuit missing.

anyway, Need to measure the pins of the ic again.



If one is pulsing the dc it would be trying to shutdown, and hear a faint ticking.

The manual is talking about the 80v line for High voltage circuit

but you need a few other voltages which could be a problem

that why I ask for the voltages?

Need the cold ground hooked up when measuring a dc on the secondary!

D110,d113,d121,d104,d105 band side of diode.

have to move your ground each time you go to Primary and secondary

to test the dc.





You need a tube and yoke also..
 
Ok, no 80vs what about the rest of the secondary voltages??

The Power Ic has then PWM in it.

that would be the circuit missing.

anyway, Need to measure the pins of the ic again.



If one is pulsing the dc it would be trying to shutdown, and hear a faint ticking.

The manual is talking about the 80v line for High voltage circuit

but you need a few other voltages which could be a problem

that why I ask for the voltages?

Need the cold ground hooked up when measuring a dc on the secondary!

D110,d113,d121,d104,d105 band side of diode.

have to move your ground each time you go to Primary and secondary

to test the dc.





You need a tube and yoke also..

IC103 readings (hot ground off filter cap):

Pin 1 = 158v
Pin 2 = 0
Pin 3 = 1.3v
Pin 4 = 0 - 0.3v (NS = not steady)
Pin 5 = 0 - 0.4v (NS)


Diodes (cold ground off chassis):

D110 - 0 - 0.8v (NS)
D113 - 0
D121 - 0 - OL (NS)
D104 - 1.6 - 1.9v (NS)
D105 - 0 - 0.6v (NS)

Again, I really appreciate your help! :)
 
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I️ wonder about the new part.

There's not much around that ic

Check for open trace around the ic.

If no shorts on the same test point diodes

See if any of the diodes cathode read low ohms

To ground.

Use the hot heat sink as the cold ground
 
I️ wonder about the new part.

There's not much around that ic

Check for open trace around the ic.

If no shorts on the same test point diodes

See if any of the diodes cathode read low ohms

To ground.

Use the hot heat sink as the cold ground
I tested each diode within the primary with a leg up and all tested within .400 - .700 ohms on the cathode side. None were shorted when reversing the leads.

Also tested caps in the primary and all were within range using an ESR meter.

I returned the original IC103, but no change when powered on. Still hear a faint ticking from the SMPS.

No broken traces found anywhere in the primary.
 
R112 and R115 lead to the vcc the voltage is low in your readout

you check the resistance of r112,r115 but is there a bad connection

on pin 3 because if the resistors are good and 160vs is on one side of

r112 and goes to r115 it should go straight to pin 3???

I would suspect the resistors have increased in resistance

because the low dc on pin 3!
 
R112 and R115 lead to the vcc the voltage is low in your readout

you check the resistance of r112,r115 but is there a bad connection

on pin 3 because if the resistors are good and 160vs is on one side of

r112 and goes to r115 it should go straight to pin 3???

I would suspect the resistors have increased in resistance

because the low dc on pin 3!

I have 160v on one side of R112, but only 2.8v on the opposite. 2.8v goes into R115.

When testing the resistance on both R112 and R115, it slowly climbed to 195k and leveled off.
 
Need to replace both

They maybe .25 watt or .5 watt

But what will be easy to fined

And fit the holes

They got to be failing under load
 
Need to replace both

They maybe .25 watt or .5 watt

But what will be easy to fined

And fit the holes

They got to be failing under load

I replaced both resistors at R112 and R115, but unfortunately no change upon power up. I'm getting the same exact voltages as before (160v on one side of R112 and only 2.8v on the opposite).

Bummer!!!!
 
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You lift the resistor going to pin

3 and test the voltage on the center

Between the two resistors

See if something at that test point

Is pulling it down.
 
You lift the resistor going to pin

3 and test the voltage on the center

Between the two resistors

See if something at that test point

Is pulling it down.
Sorry, I'm not understanding the above instructions. Do you want me lift the leg of R112 that goes to pin 3? Where exactly am I testing the voltage?

Thanks.
 
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