Waiting on parts. When I get them, I'll update this thread more.
Estimated delivery date 1/21 - 2/4........
UglyBetty
Member
Last Activity: 01-12-2022, 07:11 PM
Joined: 01-06-2022
Location: Edmond, Oklahom
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Re: Need some help with Epson Printer Power Supply C655 MAIN
Waiting on parts. When I get them, I'll update this thread more.
Estimated delivery date 1/21 - 2/4........
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Re: Neighbor has a constant drain on his car battery...
Your correct, Acura is Honda....not Toyota. My mistake. Everything else still applies.Leave a comment:
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Re: Neighbor has a constant drain on his car battery...
Here is something else. Just because the alternator "appears" to be charging at the correct voltage, does not necessarily mean the alternator is good. There are 4 huge diodes inside the alt. They can and do leak voltage. If one is leaking, it will drain the battery. The ripple of the alternator needs to be checked. A bad or leaking diode will show up in a ripple test. If you remove the large positive post and unplug the connector to to alternator and the draw goes away, you have found your problem....Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
CapLeaker,
I traced the schematic back from the +42v connection to the printhead. I was not able to find a schematic for the printhead itself, but did determine which connection was the input for the +42v. I ohmed from that point to the remaining pins and did not find anything close to a short. Again, I'm wondering if the printhead was not still wet from the cleaning process when it stopped working. Now the head has time to dry out completely. All I can do it try it. Ya know?
Sam_sam_sam...Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
Just for the heck of it, I ordered some transistors to see if I can screw up this board even more! This should be fun! Stay tuned....Leave a comment:
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Re: The Hall of Shame - Badcaps Photo Montage
Okay, here is my contribution. A few years ago I used a Motorola power supply that was from a retires base-station police band radio. I used it to build a 20amp power supply to run some of my radio gear.
I walked into the shack one day and I could smell something burning. I looked around but did not really see anything. No visible smoke. I noticed this power supply was off. I could tell this was where the stink was emanating from. I just took it out of service, set it aside and used another power supply.
I pulled it out...Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
Thanks EVERYONE for your help! You guys/gals are awesome! I'm going to call this one for now. I'll post an update when I get the "stuff" in and get it going again.Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
I wondered that myself. I numbered all of the small ribbon cables I removed from the main board to the rest of the printer. then I photographed them as I was removing them. The way the cables lay in the printer, they are pretty tight fit. I would be very difficult to get any of them in the wrong place, but I guess anything is possible. I just wonder if there was water or cleaning fluid in the circuit board located on the printhead and when I connected everything back up that water/cleaning fluid shorted...Leave a comment:
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Re: Need some help with Epson Printer Power Supply.
C12 is a 250v cap., not 25v.
Yes, I measured a short of 0.3 ohms across the +42 volt supply connections and ground.
Edit; Sorry, you are correct, I was thinking C11, not C12. Your right, it is 25v. honestly, I don't think I measured that one. Anyhow, I believe I have located the problem, but I DO thank you for your help. As you can tell, I know just enough to be dangerous!
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Last edited by UglyBetty; 01-08-2022, 01:00 PM.Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
I'll see if I can find something with the same specs, replace them and see if I can make it work.
I checked the R164. In circuit, it measures 2.4 ohms, going through that resister, through C129, measure 26.4K to ground.
Oh, and yes, all three C, E and B of the two transistors are shorted together. 0.3 ohms between each contact, regardless of test lead connections.Last edited by UglyBetty; 01-08-2022, 12:56 PM.Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
Something else fun! I put it all back together, minus the transistors, jumper GRD and PSC, I get my +43v, +5v and +3.3v back from the power supply!! Guess the transistors were the short...
What do you think? Replace the transistors and try again? Or order the main board and a print head? Main board is about $60 and the print head is around $55, used, from China of course....
I'm not ready to give up on this printer. Seems to be worth $600-$700 used.Leave a comment:
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Re: Need some help with Epson Printer Power Supply C655 MAIN
This was driving me crazy last night so I did some more digging. I just couldn't walk away from it. I'm a seasoned professional mechanic for a living and I know the importance of proper diagnosis. I also know you can learn a tremendous amount from failure analysis. So I kept going.
I found two transistors on the main board that appear to be shorted. I included a portion of the schematic of the main board. I'm posting this from my laptop and don't have a full copy of acrobat in it so I just did a screen shot...Leave a comment:
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Re: Need some help with Epson Printer Power Supply.
On C12, I just measured across the leads of the cap.
I disconnected the power supply from the main board and measured the ohm value across the +42 volt terminal and to the one of the ground terminals. It measures 0.3 ohms. I would say it's on the main board.
May just replace the main board and be done with it.....Leave a comment:
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Re: Need some help with Epson Printer Power Supply.
Voltage across C51/C52 is 0volts, but it pulses up to between 1-3 when the supply comes on, immediately drops to 0 volts when the supply kicks back off.
Voltage across C-12 is a steady 165.
I measured the resistance between the +42 volt output and ground. 0.3 ohms. I would say I have a direct short somewhere on the main board!
I am guessing my hunch about the power supply was incorrect. There are several caps on the main board. I am wondering if one of those is shorted.
...Leave a comment:
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Re: Need some help with Epson Printer Power Supply.
Thanks CapLeaker.
If you look at the schematic, on the output side, connector CN2, pin 5 of that connector is labeled "PSC". If I'm not mistaken, that stands for Power Supply Control. Studying the rest of the schematic, this is used by the processor to turn on and off the power supply.
Pin 9 labeled "ESAVE" I believe is used by the controller to put the printer into some sort of "sleep" mode or "stand-by" mode. Just in my limited knowledge and some reading I have done, I believe...Leave a comment:
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Re: Help diagnosing PWO1025 SMPS
Great to hear you had a positive outcome. I need to learn more about zener diodes.Leave a comment:
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Re: Need some help with Epson Printer Power Supply.
R_J ---Thanks so much for your reply.
I have measured other sub-ohm resistors and the leads did not add this much resistance (if any). I'm using a Fluke DVOM meter and meter leads. Leads touched together have 0.00 resistance.
The rectifier I've measured is the bridge rectifier.
I've thought about that, I also thought about it being in one of the other step-down boards located around the printer. I removed the main board from the printer and connected the power supply. With nothing connected...Leave a comment:
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Need some help with Epson Printer Power Supply C655 MAIN
Here is the back story. This printer had been sitting for about two years not used. I removed the print head to clean it (completely dried out). I cleaned it and reinstalled in. Powered the printer on, the printer started going through it's normal start-up procedure and part way through it was like the power just shut off. No sound, not lights, no error messages, it just went completely off. I suspect the power supply.
At any rate, the schematic for the power supply is included.
There is a lot going on on the low voltage side that I am not able to make heads or tails... -
Re: New Members - please post your introductions here
Saying hello....50 something Amateur Radio operator and Jeep Junkie in Oklahoma. Here to get some help with a power supply for my beloved large-format printer, and to learn all I can from the people who know more than I.Leave a comment:
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