Blowing fuses in my Dialog 4 console - Help!
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 31
  1. #1
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default Blowing fuses in my Dialog 4 console - Help!

    I'm blowing a fuse on the power supply board in the operator console of my D4. It's the 3.15A fuse closest to the rear edge of the board. It blows immediately as soon as power is connected. It's the fuse inside the holder in the center of the second photo. Because of this the monitor stays dark and the console does not communicate with the PC in the cabinet. I've tried a borrowed good power supply, disconnecting the monitor, and disconnecting the other ribbon cables.
    Has anyone here experienced this? Anyone know exactly what that fuse supplies power to?
    When the shop is perfectly quiet I can hear a whistle/squeal/hiss noise from the monitor area when power is on, is that normal?

    I'm out of things to try, any help would be gratefully appreciated!

    20200418_184851.jpg

    20200418_184905-1200.jpg

  2. #2
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,349
    Post Thanks / Like
    Likes (Given)
    1947
    Likes (Received)
    2683

    Default

    Get in touch with Wrench (Alan) if you can....He has rebuilt these boards for me in the past and has a working knowledge of the board and its circuit.
    Guessing he would know what that fuse feeds.
    Cheers Ross

  3. Likes Mud liked this post
  4. #3
    Join Date
    Feb 2001
    Location
    Redwood City, CA USA
    Posts
    5,124
    Post Thanks / Like
    Likes (Given)
    204
    Likes (Received)
    1021

    Default

    Mine whistles during warmup, but fuses stay whole. I think the whistle is from the CRT fly back circuit. Do you have the circuit diagrams?


    Sent from my iPhone using Tapatalk

  5. #4
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    3,034
    Post Thanks / Like
    Likes (Given)
    1970
    Likes (Received)
    1114

    Default

    I know nothing about the Dialog 4 and have zero experience with it. But I have plenty of experience diagnosing and fixing power supply (PS) problems in other electronics.

    You should start by isolating the problem. If this PS feeds circuitry which is off the board, start by removing all of the boards that it feeds. If the fuse still blows, then the problem is on the PS board itself. If the fuse no longer blows, then plug in the other boards, one at a time, until the fuse blows. That locates the board which is responsible.

    The method is classic "divide and conquer". You subdivide over and over to identify the area of circuity which is responsible. As much as possible you do this by unplugging connectors or disconnecting terminals (rather than unsoldering parts) to isolate different sections. A good designer has this eventuality in mind, and makes it easier by letting you unplug relays, pull out fuses, remove links from terminal blocks, and so on.

    One other important bit of info. Is this fuse on the primary side of a transformer (in a 120V or 230VAC circuit)? Or is it on the secondary side or in a lower-voltage AC or DC circuit? Measure the AC and DC voltage across the fuse holder (with no fuse inside) with a multimeter.

  6. #5
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    Quote Originally Posted by rklopp View Post
    Do you have the circuit diagrams?


    Sent from my iPhone using Tapatalk
    I have an orange book. If they are as hard to read as the machine wiring diagrams I don't stand much chance of understanding them. I will take a look at them, I guess this is the time to learn.

  7. #6
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    Quote Originally Posted by ballen View Post
    You should start by isolating the problem. If this PS feeds circuitry which is off the board, start by removing all of the boards that it feeds. If the fuse still blows, then the problem is on the PS board itself. If the fuse no longer blows, then plug in the other boards, one at a time, until the fuse blows. That locates the board which is responsible.

    The method is classic "divide and conquer". You subdivide over and over to identify the area of circuity which is responsible. As much as possible you do this by unplugging connectors or disconnecting terminals (rather than unsoldering parts) to isolate different sections. A good designer has this eventuality in mind, and makes it easier by letting you unplug relays, pull out fuses, remove links from terminal blocks, and so on.

    One other important bit of info. Is this fuse on the primary side of a transformer (in a 120V or 230VAC circuit)? Or is it on the secondary side or in a lower-voltage AC or DC circuit? Measure the AC and DC voltage across the fuse holder (with no fuse inside) with a multimeter.
    That seems logical, I'll pursue that. I'm afraid of hurting precious Dialog boards by doing something dumb, I was hoping someone had already experienced this.

  8. #7
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    Quote Originally Posted by ballen View Post

    You should start by isolating the problem. If this PS feeds circuitry which is off the board, start by removing all of the boards that it feeds. If the fuse still blows, then the problem is on the PS board itself. If the fuse no longer blows, then plug in the other boards, one at a time, until the fuse blows. That locates the board which is responsible.
    I don't see an easy way to measure the load across the fuseholder, which is soldered to the PCB and fully enclosed. How do I test this way without blowing an endless number of $1 fuses? (which need to be shipped in)

    Is removing all the boards (except the memory board which should stay in place to retain it's data) then applying power for testing after inserting each board the only way to test? I'm a little concerned that I'll plug in a fatal combination of boards accidentally.

  9. #8
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    3,034
    Post Thanks / Like
    Likes (Given)
    1970
    Likes (Received)
    1114

    Default

    Quote Originally Posted by Mud View Post
    I don't see an easy way to measure the load across the fuseholder, which is soldered to the PCB and fully enclosed.
    Jury-rig two pieces of stranded wire to carry the connections a couple of feet away to a nearby bench or stool. You can either solder the wires to the PCB at the same places where the fuse holder connects (no need to remove the fuse holder) or you can use some bits of plastic and ingenuity to fit the stranded wires inside the fuse holder to make contact inside. SHUT OFF POWER FIRST AND BE CAREFUL NOT TO SHORT THE CONNECTIONS INSIDE THE FUSE HOLDER. Outside the machine, solder the stranded wires to an external fuse holder.

    How do I test this way without blowing an endless number of $1 fuses? (which need to be shipped in)
    Pick your "external" fuse holder to be a type for which you can easily get lots of cheap fuses. It does not need to be the same style fuse, any quick-blow wire fuse type with the same or slightly smaller current rating will work. Alternatively, you can wire in a circuit breaker or a correctly-chosen resistor, but this is the simplest.

    Is removing all the boards (except the memory board which should stay in place to retain it's data) then applying power for testing after inserting each board the only way to test? I'm a little concerned that I'll plug in a fatal combination of boards accidentally.
    Other Dialog owners (Ross?) need to answer -- as I wrote above, I have zero experience with those. But no decent engineer -- and I have the impression that the Dialog engineers were very good indeed -- would design a system where any combination of boards inserted or removed from a backplane could do damage. Be sure to power down before removing/adding boards!

    Alternatively, if you have schematics, first identify the fuse in question, second, identify where it gets its source of current, and third, identify where it carries that current to. For most of the electronics that I have fixed, that wasn't an option because there were no schematics to be had.
    Last edited by ballen; 04-20-2020 at 03:49 AM.

  10. Likes Mud liked this post
  11. #9
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,349
    Post Thanks / Like
    Likes (Given)
    1947
    Likes (Received)
    2683

    Default

    Think Bruce's technique is valid...Do the cards one at a time install and remove only with all power off. To be honest i have not tried this with all boards, but know it works fine on the axis boards (NZP)
    Schematic for the board is in the orange book. There are factory upgrades to the board that are not shown in the prints.
    Print is very difficult to read, that is why i suggested you contact Wrench...I know he spent quite some time sorting out the circuits and is familiar with the upgrades.
    I would look first at the memory board with its onboard battery.....
    Cheers Ross

  12. Likes ballen, Mud liked this post
  13. #10
    Join Date
    Apr 2020
    Country
    ITALY
    Posts
    5
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2

    Default

    Quote Originally Posted by Mud View Post
    I'm blowing a fuse on the power supply board in the operator console of my D4. It's the 3.15A fuse closest to the rear edge of the board. It blows immediately as soon as power is connected. It's the fuse inside the holder in the center of the second photo. Because of this the monitor stays dark and the console does not communicate with the PC in the cabinet. I've tried a borrowed good power supply, disconnecting the monitor, and disconnecting the other ribbon cables.
    Has anyone here experienced this? Anyone know exactly what that fuse supplies power to?
    When the shop is perfectly quiet I can hear a whistle/squeal/hiss noise from the monitor area when power is on, is that normal?

    I'm out of things to try, any help would be gratefully appreciated!


    20200418_184851.jpg

    20200418_184905-1200.jpg
    transistor T1, T2 or ceramic resistor R9 may have burnt out.

  14. Likes Mud, ballen liked this post
  15. #11
    Join Date
    Oct 2016
    Country
    SWITZERLAND
    Posts
    69
    Post Thanks / Like
    Likes (Given)
    18
    Likes (Received)
    25

    Default

    If I remember correctly, NSV 52 board takes something like 42VDC and converts it down to 5,15,24VDC.... Back then when I fixed my FP2NC and recapped NSV 52, I didn't realize that the GND terminals of the big aluminium cap are also used as a bridge, so it ended up not working. So I used a bench power supply instead of the 42V from the machine for troubleshooting and eventually got it back working.

    My approach would be to remove NSV52 and use external power supply as input source and see wether it outputs the correct voltages. If all voltages are good, then put NSV52 back into machine and pull out cards until the problem disappears. Then you know which card is shorted, so you can search for shorts on that card only.

  16. Likes Mud liked this post
  17. #12
    Join Date
    Oct 2012
    Location
    Austria
    Posts
    176
    Post Thanks / Like
    Likes (Given)
    14
    Likes (Received)
    46

    Default

    I change this exact fuse every month on average, the last 10 years.I have not yet discovered what the problem is, but they always burn 5 to 30 secs after powering from the main switch.I cant find the original fuses with the little crystal balls, but I believe they are "slow burnt" fuses. After change, everythings works well...

  18. Likes Mud liked this post
  19. #13
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    I pulled the NSV out and powered it up by itself. The fuse stayed intact, and the led next to it lit up.
    I pulled every card except the memory card in slot 10, reinstalled the NSV, it blew the fuse immediately on power up. I have 2 NSVs, both behaved the same out of the machine. and both blew the fuse in the machine. I didn't want to lose all the data in the memory card, but is that the next card to remove? It has a remote battery in the base of the console, I assume the SAFT battery on board is NG.

  20. #14
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,349
    Post Thanks / Like
    Likes (Given)
    1947
    Likes (Received)
    2683

    Default

    Not sure, but i think if you pulled the K10 jumper (which you will need to do if you remove all the cards except the memory board), pretty sure all your data is gone already......
    Would try disconnecting the external battery and try your power test again.
    Cheers Ross

  21. Likes Mud liked this post
  22. #15
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    3,034
    Post Thanks / Like
    Likes (Given)
    1970
    Likes (Received)
    1114

    Default

    Hi Mud,

    If I have understood correctly, the fuse is blowing on the NSV board, which is a power supply. If you power up the NSV by itself outside of the crate, then all is OK. But if you power up the crate with the NSV plus the memory card inside, then the fuse blows. Is that right? It seems to implicate the memory board. If you do pull out the memory board, next thing is to try the NSV card by itself in the crate. This is to eliminate the possibility that you have a connector/backplane short inside the crate, and the problem is unrelated to the memory card.

    Cheers,
    Bruce

  23. Likes miburk liked this post
  24. #16
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,349
    Post Thanks / Like
    Likes (Given)
    1947
    Likes (Received)
    2683

    Default

    John:
    On the off chance that the data is still intact on the memory board, you could patch in a new battery on the extension wires while the old one was still present, then cut off the old battery and try your power up test.
    If you have the remote battery, i would definitely remove the on board battery from the card.
    Cheers Ross

  25. #17
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    Quote Originally Posted by ballen View Post
    Hi Mud,

    If I have understood correctly, the fuse is blowing on the NSV board, which is a power supply. If you power up the NSV by itself outside of the crate, then all is OK. But if you power up the crate with the NSV plus the memory card inside, then the fuse blows. Is that right? It seems to implicate the memory board. If you do pull out the memory board, next thing is to try the NSV card by itself in the crate. This is to eliminate the possibility that you have a connector/backplane short inside the crate, and the problem is unrelated to the memory card.

    Cheers,
    Bruce
    But if you power up the crate with the NSV plus the memory card inside, then the fuse blows. Is that right?
    Yes that's correct.

  26. Likes ballen liked this post
  27. #18
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    Quote Originally Posted by AlfaGTA View Post
    John:
    On the off chance that the data is still intact on the memory board, you could patch in a new battery on the extension wires while the old one was still present, then cut off the old battery and try your power up test.
    If you have the remote battery, i would definitely remove the on board battery from the card.
    Cheers Ross
    Ican't quite follow the wiring from the battery, it doesn't go directly to the board, it seems to go to a connector on the backplane. I'll look closer. tomorrow.

  28. #19
    Join Date
    Jan 2011
    Location
    Germany,35764 Sinn
    Posts
    59
    Post Thanks / Like
    Likes (Given)
    23
    Likes (Received)
    12

    Default

    Quote Originally Posted by Mud View Post
    Yes that's correct.
    It sounds a little bit freaky.
    The Fuse which blows is SI1 and LED D1 is off.
    This indicates, that the +15V Regulator is overloaded or does not work.

    You tested the nsv56 without any other card and it works. There for the +15 V Regulator works.

    The freaky thing: The NSP Card with my knowledge does not use the +15V Supply.

    So i agree to ballens idea, that there may be a defekt on the backplane.

    If the battery on the nsp56 is working, you can plug the card out and the programms should stay there.

    Can you measure the voltage of the battery on the NSP Card? should be around 3.6V (nominal)

    NCR53 and Monitor also were of during your test?

    Regards Michael

  29. Likes ballen liked this post
  30. #20
    Join Date
    May 2002
    Location
    South Central PA
    Posts
    13,886
    Post Thanks / Like
    Likes (Given)
    2432
    Likes (Received)
    3675

    Default

    I'm making some progress. Yes the NCR 53 is out and the monitor is unplugged. I pulled all the cards except the NSP56, and it still blew the fuse. So I pulled the NSP56, and it still blew the fuse. The only thing that appeared to be still connected was the fan. I kept looking and noticed that half of the NBP cable is plugged into the backplane underneath the cage. I unplugged that and it didn't blow the fuse, so it seems to be in the NBP.
    I have 3.8V in the Saft battery on NSP, less than 3 in the 6pack battery so I'm working on the 6 pack battery. I have parts coming for that tomorrow. I have another NBP board to connect after I get the battery situation resolved.
    The battery I thought was a remote battery for the NSP56 is actually the 6 pack battery. This is the first time I've gotten this far into the electronics of this machine, obviously some of the problem here is my inexperience. I appreciate all your interest and help very much!

    What does that 7.2V 6 pack battery do? I understand the control won't start if it's dead, but what does it supply power to and what does it do?


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •