Accessing & repairing the PSU: Rex Rotary 1280 (Gestetner 5375/Nashua CP375) (2)

[Eight-Days-a-Week]

Re: Rex Rotary 1280 Digital Duplicator (Copy Printer)
(may be similar to: Gestetner 5375 & Nashua CP375)

Machine Dead:

Hi,
I'm new to this forum and hope someone can help with a problem I have with the above.
Especially if you have a personal experience of working on this particular model, as it seems to differ a little bit from the other models of that period.

The 1280 etc, is the A3 version, and although it's basically the same as the A4 versions of that period, it seems to have some layout differences.

This has been in my possession from new, and has had very little use.
I came to use it recently and 'nothing-happens' when I switch it on.

I say 'nothing-happens' but very occasionally, when you switch it on, there is a very faint flash of info on its display, that decays in less than a second.

Many years ago (when I had brown hair) I trained on this then range of Rex/Gestetner Digital Duplicator.
(BTW: Trained by a nice guy at Crawley, London. Now works for himself, anyone know how to contact him?)

I have various service manuals, and the one for the 1280, says, a dead machine is caused by the main fuse (FU1) on its DC-Power-Supply PCB.

But the manuals section on the Power Supply is very sparse to say the least.
I'm not sure if my missing pages was an error, or if they simply weren’t available in the first place.

On this model, the machines exploded diagram (on the back of its 'Point-to-Point-Diagram) indicates that its DC-Power-Supply is in the centre of the machine under the drum, but there is no access from the front of the machine.

Looking at other sections of the manual, it seems that the fan may be mounted on top of the DC-Power-Supply PCB, and under the drum, and under the Transport-Unit.
So the Transport-Unit would need to be removed first to get to the Fan/Power Supply.

Obviously, I don't want to have to remove stuff unnecessarily, so I would appreciate any practical guidance.

Also I note: That when changing or repairing the PSU, or changing the Thermal-Head, the Thermal Head Voltage, needs to be adjusted on the PSU, but exactly how you are supposed to do this, (with the PSU located where it is) is not clear!

Many Thanks Mac

[blackcat4866]

It looks like something got corrected.

Good luck. =^..^=

[slimslob]

How old is that? A Gestetner 5375 would be a C210 product code. The oldest manuals that I have are for the C211.

I was able to find a service manual online. The odd numbered pages have 1 December 1993 printed on the upper right hand corner.

Searching "Fuse" O see that there are 2 fuses, FU101 and FU102 on what I believe is the Main PCB mounted at the upper right corner under the front cover. That board also has 5 trimmers for making adjustments, one of them might be the one you need. There is also a circuit breaker on the incoming AC line.

Good luck on a machine that old as parts may be hard to find.

[Eight-Days-a-Week]

How old is that? A Gestetner 5375 would be a C210 product code. The oldest manuals that I have are for the C211.

I was able to find a service manual online. The odd numbered pages have 1 December 1993 printed on the upper right hand corner.

Searching "Fuse" O see that there are 2 fuses, FU101 and FU102 on what I believe is the Main PCB mounted at the upper right corner under the front cover. That board also has 5 trimmers for making adjustments, one of them might be the one you need. There is also a circuit breaker on the incoming AC line.

Good luck on a machine that old as parts may be hard to find.

Many thanks slimslob.

The date on my manual is April 1991.
The 'Point-to-Point-Diagram' has a C210 on it.
The Fualt-Chart says a dead machine is caused by (FU1) on its DC-Power-Supply PCB.
The Main PCB that you mention, on this machine, I think is the control PCB, which is the largest PCB on the machine, at the front-top-right.

None of the PCB's that I can see look like the 'DC-Power-Supply PCB' which has FU1.
So I need to find that to start with.

Which may under the Transport-Unit, as I said earlier, or possible slightly to the left of the drum, near the output section of the machine.

I've got the outer plastic covers off, so now it looks like I have to start pulling off any internal cover etc, to see if it's behind them.

The Noise filter is on the rear bottom left side, where the mains lead comes into the machine, so the PCB could be infront of that, but hidden inside the body of the machine, infront of the Paper Exit Section?

None of the manual info that I have shows any detail of the 'DC-Power-Supply PCB' except...

In the (exploded) parts section of the manual @
16: Paper Exit Section: Page 40/41

This shows the Power-Supply-Unit (item 7) + Fuse: 6.3 amp + Fuse: 15 amp.
It's really not clear where this PSU is supposed to be, on the machine,
it looks like it's at the output side (on the base) of the machine !?

Many thanks.

Anyone else have more info.

[slimslob]

It should be the board that the AC power leads connect to after the circuit breaker. On most older Gestetner models it is under the back cover, bottom corner at the paper feed table end. FU1 should be either a glass tube AGC 15 or an asbestos tube ABS 15.

[Eight-Days-a-Week]

It should be the board that the AC power leads connect to after the circuit breaker. On most older Gestetner models it is under the back cover, bottom corner at the paper feed table end. FU1 should be either a glass tube AGC 15 or an asbestos tube ABS 15.

Thanks for you assitance:

Looking at other A4 models of this period, the DC-Power-Supply PCB does appear to be on the rear of the machine, but this A3 models seems different, eg:

Here's what I think so far...

Please the the attached images.

My 'Point-to-Point-Diagram' shows:
The mains lead, goes to Main Switch, Circuit Breaker, Transformer, DC-Power-Supply PCB.

The Fault-Chart says a dead machine is caused by (FU1) on its DC-Power-Supply PCB.
The DC-Power-Supply-Unit is shown in the following 4 images, eg:

image 1/2: item 7, including: Fuse 105: 6.3 amp + Fuse 107: 15 amp. (I think one of those is FU1)

image 3: item 27, which appears to be under the fan.
(the locaton seems to contradict item 7 ? Although the shape of the unit seems similar)

image 4: item 55, this is the AC Drive PCB, which is fed from the other boards.

Many thanks

[slimslob]

Item that the 15 amp fuse is the main fuse. If there is no power, then it would be the main fuse blown. Most like those fuses are not on the outside, too much electrical shock hazard.

[Eight-Days-a-Week]

Item that the 15 amp fuse is the main fuse. If there is no power, then it would be the main fuse blown. Most like those fuses are not on the outside, too much electrical shock hazard.

OK: I've located the PSU.
It's a: Ricoh Power Supply Unit - A4: C210 8301

So does anyone have any experience of repairing these PSU ?

It seems that C210 is the machine version and
8301 is the PSU version.

8301 is used in various machines, (with different prefixes), so these powers supplies 'may' be similar to those used in other machines.

I've yet to start checking this PSU, but I can see that various electrolytic capacitors seem to be leaking, which will be a common problem in equipment of this age.

[slimslob]

It it is more than the fuse,you might be out of luck. All it takes is 1 component of a switching power supply to fail and it will crowbar the entire PSU. With out on board schematics proper test equipment and knowledge on repairing power supplies it is near impossible to repair.

[blackcat4866]

OK: I've located the PSU.
It's a: Ricoh Power Supply Unit - A4: C210 8301

So does anyone have any experience of repairing these PSU ?

It seems that C210 is the machine version and
8301 is the PSU version.

8301 is used in various machines, (with different prefixes), so these powers supplies 'may' be similar to those used in other machines.

I've yet to start checking this PSU, but I can see that various electrolytic capacitors seem to be leaking, which will be a common problem in equipment of this age.

Have you tried Hytec?:
Factory Authorized Circuit Board Repair by Hytec Dealer Services, Inc.

=^..^=