RISO RP 3700 DIY service

[benoitv]

Hi,

Summer is coming, that means a bit less work for us, and a good time to service our pre-owned risograph.

The counter on the machine says 500k copies, but when I check the usage count on the screen, it is closer to 4 million... I guess this is the right figure.

So far, the machine is running smoothly, although registration could be better. I also noticed that by default, the prints are not centered on the sheet (it varies with the different drums), but nothing we can't resolve using the positionning functions of the printer.
Registration is pretty crucial as I often use this riso for quadtone printing, and i'd like to tune it as good as possible!

I'm located in France and service is really expensive here as less and less companies are offering it, so I was thinking of servicing the machine myself.

I know there are a couple of very skilled technicians here, so i'd really appreciate if I could get some advice about what to look at first, what parts I should replace anyway, what parts to check for excessive wear, etc...

Also, in case anyone has a parts source in Europe, or even in the US, that could be really great!

thanks,

Benoit

[JustManuals]

This site is for professionals in the business. It says so in the forum rules you agreed to when you joined. The pro's here giving you information are taking money out of another technicians pocket. What business are you in? Do you give away professional secrets to any Tom, Dick or Harry who walks through the door? Don't be a tight ass, call a technician!

[RRodgers]

This site is for professionals in the business. It says so in the forum rules you agreed to when you joined. The pro's here giving you information are taking money out of another technicians pocket. What business are you in? Do you give away professional secrets to any Tom, Dick or Harry who walks through the door? Don't be a tight ass, call a technician!

[benoitv]

Hi,


I was orginally trained as an Epson LFP technician, so I thought i'd be accepted here, if this is not my place please excuse me.

I started my printing business two years ago, we mainly do exhibition prints for museum using inkjet printers, but also started to experiment quadtone printing with a riso for artist books.

As I used to service printers, i'm not trying to avoid calling a technician, but please keep in mind that the context in Europe is very different from what you have in the US. Riso is kind of dropping the duplicopier line, it's getting harder and harder to even by consumables: they're trying to push the comcolor line, and don't give a shit for older material.

Most service companies do not offer riso maintenance service anymore, as from what I heard it's harder and harder to get parts from Riso, and they move to laser copier service.

So i'm kinda stuck here, I have to do it myself as I don't want to try 10 different companies who may fuck up my printer...

If you do understand this situation, your help will be appreciated. Otherwise i'd be happy if anyone has a reliable service company in nothern France / Belgium they can advise...


thx,


Benoit

[20gaugeO/U]

RP's were over engineered. When something breaks it's usually pretty major. Invest in a service & parts manual and keep the machine clean is my recommendation.

[benoitv]

Hi,


thanks, that's what I just did a few days ago. Removed and cleaned the different rollers, vaccumed everything including the PCBS on the back, everything was full of paper dust. The timing roller cleaning helped a lot, i'm getting much better registration now!

Benoit

[LA TECH]

Riso came up with a new upgrade for the main driving ass'y for that series they went to metal instead of plastic, those are the gears that drive the drum if they are not metal they wear out going off timing giving you misregistration also replace the one way and load spring they are very critical in the registration process too and should be replaced often when needed. the horizontal screw shaft in the drum needs to be lubed

[mixedfeelings]

Re: RISO RP 3700 DIY service

Do you know if it is possible to still purchase the metal upgrade main drive assembly? I am wondering if this might be to blame for my registration / skewing difficulties (I can't get the prints to stop skewing in clockwise direction). I have an RP3700 with the original plastic gears.

[jermyth]

Re: RISO RP 3700 DIY service

Main drive gear would not give you skewed copy. Is the skew on the master or just the prints?

[mixedfeelings]

Re: RISO RP 3700 DIY service

yes there appears to be a skew of about 1/16th on the master. I measured the distance from the silver edge of the drum screen to the master on the top and bottom of the F side. it's skewing clockwise, so the bottom is a little closer to the edge.

Is this a write roller problem?

[mixedfeelings]

Re: RISO RP 3700 DIY service

Well, i've messed something up...

I cleaned the master making rollers and took the front and back covers on to check if the set screws on the write rollers were tight, advice i'd seen in other threads. They were. I also carefully and slowly ran a piece of cardstock through master making set up (with the tph up). But, when I put it all together and tried to run a test print nothing burned on the master. everything seems to be running through the system smoothly, but no image.

At one point there was a "TPH not connected error" but I am no longer.

I also got a T95-056 error - but was able to correct that by clearing all of the saved memory and restoring to default settings.

Any ideas as to why the TPH isn't making a master? is there a test I can run to diagnose the problem further?

[20gaugeO/U]

Re: RISO RP 3700 DIY service

Test mode 50 should make a checkered pattern from memory. Make sure you have 11X17 paper in the tray. 50-55 all make different patterns.

I'd check or replace the impression roller under the drum for a skewed master. Any wrinkles on the drum shell?

[mixedfeelings]

Re: RISO RP 3700 DIY service

Thanks!

I ran test modes 50 and 51, and sadly neither test image burned onto a master. At first I thought that I had somehow cleared those test patterns when I cleared the memory - so i tried to make an image from the glas top - nothing. Everything is running smoothly, the paper is feeding through the machine as expected, masters are going on and off the drum - just no master is made and there is no error. so strange!

Regarding the skew and the pressure roller. I took it out, inspected it, cleaned it up a little. It seems like its in good shape - but I ordered a new one just in case. One of my strategies has been to replace all of the commonly replaceable parts just to start from scratch with that regard (stripper pad, feed tires, etc.). I noticed there is a way to adjust the parallelism of the pressure roller could that affect skew?

[Iowatech]

Re: RISO RP 3700 DIY service

If the test modes didn't make a master, that means the thermal head isn't working. Hopefully the thermal head isn't broken, it is extremely expensive. I'd take a look at the connectors on top of the thermal head, I had one that came loose after the thermal head cycled a number of times. Also check the connectors on the main board and the power supply board. Check for blown fuses on the power supply board.
As for the skewed master, clean the inside of the clamp, and maybe see if there's a way you can increase the amount of master in the clamp.
Hope that helps.

[mixedfeelings]

Re: RISO RP 3700 DIY service

Thanks! I will try that stuff for the TPH tonight.

re: skewed masters - one thing I should mention is that it seems to be on every drum - so I don't think its the master clamp on the drum - is there another clamp in the master making assembly?

Thanks again!