Jensen A530

[TW1990]

Hi All, picked up my first chipper yesterday evening. 
 

Travelled about hour and half to pick it up in the evening from a fairly big forestry contractor. Before we got there he did say everything was working but hadn’t been used in about two years and been stored in the work shop. 
 

She started up fine but the feed roller’s were turning very slowly and didn’t even want to chip small twigs with out jamming. 

He knocked some money off for us and off we went. Had a spare morning so got her opened up in some better light so see what was going on. 
 

She seem to moving better in reverse but still jamming with the smallest of brash, seems to be enough hydrologic oil but almost like shaft is struggling. 
 

any one else had a similar issue with this model of chipper that I can sort or can recommended any one in the North Cornwall area to look at it. 
have attached couple videos 

Edited October 5, 2023 by TW1990
Adding another video

[GA Groundcare]

Don't run it with the flywheel housing open!!

 

Would check hydraulic pump belt tension, is there a speed valve fitted? Probably located on the forward / reverse valve block. If so, is it seized? If it turns is it actually turning inside or just the plastic metal cover?

 

Hydraulic oil level, hydraulic oil condition? If the stop bar activates the rollers forwards and reverse, remove the rod between the valve block and the stop bar. Then operate the forward / reverse directly at the valve block? There is three detent positions, reverse, forwards and stop. These three positions should feed nice and positive and not sloppy. If it works fine testing at the valve block your problem is on the connecting rod. There is a ball bearing that slides across a knuckle. This knuckle can wear and the detent be between positions causing slow rollers.

 

Elmstar are down in Newton Abbott. They know Jensen products well. 

[Mike Hill]

It's probably the circuit board. But check.That you have a steady orange light on the circuit board when the chipper is running full chat. If not check the gap between the sensor and the flywheel,should be a width of pound coin.

 

If so or not try resetting the speed sensor buy removing the cover on the circuit board and running chipper full chat,then pressing the first and last buttons simultaneously until the red light flashes,then reduce the revs 30% and press the first and middle buttons simultaneously until the light flashes again.

 

If still no luck check wires to feed roller solenoid when running you should have 12v at the solenoid. 

 

You could have a bad solenoid, but they'd tend to last and are cheap.

 

Take the circuit board off and check the back of it for visual faults,the boards do get old or water damaged. Good luck

[Husqvarna King]

All above advice is very good. Has it got the sensor/switch under the hopper like the tracked ones? If so check that. Also make sure that ignition is all the way on, if the one at work slips back slightly ours has similar symptoms to yours until you turn the key all the way round

[josharb87]

You sure the engines running flat out? 
 

my old one the rollers would be spinning 5 times faster than that. I do seem to/want to remember that the rollers crept with no power like that when revs weren’t all the way up. 

[Treetom15]

41 minutes ago, josharb87 said:

You sure the engines running flat out? 
 

my old one the rollers would be spinning 5 times faster than that. I do seem to/want to remember that the rollers crept with no power like that when revs weren’t all the way up. 

I’ve got an A528t and yes the rollers do creep at low revs, it almost looks as though the rollers think the revs aren’t at full-mine does the same as the chipping video, they turn at low revs but a small piece of brash stops them. Like the pump is just over running slightly. 

[carlos]

5 hours ago, Mike Hill said:

It's probably the circuit board. But check.That you have a steady orange light on the circuit board when the chipper is running full chat. If not check the gap between the sensor and the flywheel,should be a width of pound coin.

 

If so or not try resetting the speed sensor buy removing the cover on the circuit board and running chipper full chat,then pressing the first and last buttons simultaneously until the red light flashes,then reduce the revs 30% and press the first and middle buttons simultaneously until the light flashes again.

 

If still no luck check wires to feed roller solenoid when running you should have 12v at the solenoid. 

 

You could have a bad solenoid, but they'd tend to last and are cheap.

 

Take the circuit board off and check the back of it for visual faults,the boards do get old or water damaged. Good luck

is there a way to bypass the antistress system? somthing about a paperclip bridging two terminals, could be a way of narrowing the problem.

we had problems with our stress boxes on ocasion,

[Mike Hill]

1 hour ago, carlos said:

is there a way to bypass the antistress system? somthing about a paperclip bridging two terminals, could be a way of narrowing the problem.

we had problems with our stress boxes on ocasion,

 

Yes

 

Simply run a wire from a wire in the ignition to the solenoid,put a fusible link in there and earth the negative terminal on the solenoid to the chipper .

 

You can bypass the reset buttons by bridging some contacts on the circuit board. I can't remember what I did off hand but I have a picture of it.Simply a wire joining one contact to another.

[GA Groundcare]

15 hours ago, Mike Hill said:

 

Yes

 

Simply run a wire from a wire in the ignition to the solenoid,put a fusible link in there and earth the negative terminal on the solenoid to the chipper .

 

You can bypass the reset buttons by bridging some contacts on the circuit board. I can't remember what I did off hand but I have a picture of it.Simply a wire joining one contact to another.

 

If its an older Jensen with the forward reverse on the stop bar this won't be the case.

 

Can the OP get some photos of the forward / reverse valve block and operator controls? 

[Mike Hill]

2 hours ago, GA Groundcare said:

 

If its an older Jensen with the forward reverse on the stop bar this won't be the case.

 

Can the OP get some photos of the forward / reverse valve block and operator controls? 

Yes it will.

 

I guess it depends on what you term old? My 530T is from 2007 and my 528 was 2002.

 

The circuit board was the same between the two so was the wiring sequences on the boards themselves. Same on my big Jensen tow behind as well.