[Misc] RA-4200 - light streaks down middle...

[The Copy Man]

RA-4200 getting light streaks about 1/2 inch wide down pages top to bottom. Always in the same spot (doesn't move) down the middle of the pages. I can see it on the master too. Bad Drum? I removed the master from the drum and the drum screen appears OK in the affected area... I'm a copier guy but told them I would take a look at it. Are drums still available for this? Can we convert a color drum to Black?

Steve.

[20gaugeO/U]

Re: RA-4200 - light streaks down middle...

OLD machine 25 years, parts not available

If the drum surface is black all the way around it is fine. If there is a visible white streak on the drum surface then there is something inside the drum caught up in the internal parts leaving a void area.

If the drum is black but you can see the voided image burned on the master then either 1) there is white out on the scanner glass or 2) there's a huge buildup on the TPH surface and may be cleanable or may be burned out in that area.

There are dip switches under the cover if you wanted to switch a color drum to black but I doubt that is going to fix the problem from what it sounds like.

[Iowatech]

Re: RA-4200 - light streaks down middle...

RA-4200 getting light streaks about 1/2 inch wide down pages top to bottom. Always in the same spot (doesn't move) down the middle of the pages. I can see it on the master too. Bad Drum? I removed the master from the drum and the drum screen appears OK in the affected area... I'm a copier guy but told them I would take a look at it. Are drums still available for this? Can we convert a color drum to Black? Steve.

Have you checked for what I used to call the "unremoved master strips of doom (UMSOD)" underneath the actual master on the drum? That was a frequent issue with the RG to GR series Risos, generally caused by the voltage from the outlet the machine was plugged into being outside the acceptable range. If that's not the problem, it sounds like you probably aren't running enough prints per master. You need to run at least twenty prints off every master, otherwise this will happen. If there's an actual defect on the master (pull it off the drum and look at the pattern created by the thermal head), unless you have access to a parts machine that has an actual working thermal print head, that RG is dead. If you want to source a replacement thermal print head, be aware that it was the most expensive part of the machine when it wasn't obsolete (about 1 Kbuck) so it probably will still be pretty expensive. If I'm mistaken with anything here, I apologize. That was just the best I could come up with based on what little information you shared here so far.

[The Copy Man]

Re: RA-4200 - light streaks down middle...

Riso Test 2.jpgRiso Test Copy.jpg

Okay see above for samples of what it is doing...

Steve

[20gaugeO/U]

Re: RA-4200 - light streaks down middle...

Put Legal size paper in the machine and run service mode 117, 118, 119, 120- I can't remember if the RA will run the checkerboard test pattern 120. Run a handful of each printout. It looks like TPH to me since it's in the same spot on both. But by running the internal test modes you'll cancel out any scanner issues.

[The Copy Man]

Re: RA-4200 - light streaks down middle...

Thanks for the heads up. I downloaded the service manual and didn't find a way to get into service mode... could you walk me through getting into service mode and running these tests? Like to see if it's Scanner or TPH (TPH = Thermal Print Head?).

Steve

[20gaugeO/U]

Re: RA-4200 - light streaks down middle...

Turn off machine. Hold down both Line/Photo and Master/Print button and keep them held down while turning the machine on. Should pop up with a number which is the firmware, press stop to clear it and then input one of the numbers (120) and press start. It should start making a master. Hold down Reset to get out of service mode and run prints. You may have to move the registration down the page so it doesn't jam on the sep finger

[The Copy Man]

Re: RA-4200 - light streaks down middle...

Ok here is what the test print revealed (Proves Scanner is ok)...

Your thoughts?

Steve.Scan040.pdf

[Woxner]

Re: RA-4200 - light streaks down middle...

replace the press roller its bowed (worn and not against the drum) common on these

[20gaugeO/U]

Re: RA-4200 - light streaks down middle...

TPH is burned out every spot there is a line going down the page, it will eventually get worse. It's more noticeable when multiple lines are close together.
Take a soft clean cloth, Iso alcohol and clean the TPH with some force (like your fingernail behind it- you can't really make it any worse). Any TPH out there will be old, used and already may have the same issue.

It's old, use it as long as you can stand it

[The Copy Man]

Re: RA-4200 - light streaks down middle...

Thanks bro, dumb question... where is the TPH located? (Under top right cove where masters load?


Steve.

[20gaugeO/U]

Re: RA-4200 - light streaks down middle...

Yep it's the brownish (or greenish- I can't remember) glasslike piece that makes contact with the top of the master roll when you close the master making unit. There should be "cleaning instructions" in the book if you have it

[The Copy Man]

Re: RA-4200 - light streaks down middle...

Thanks a lot for all the help! I cleaned the TPH and it works great now.

Steve.