[Solved] Bosch GWS 850 CE worked, and after a few months' break it did not. Other con

Good morning,

I purchased (one or two years ago) a used Bosch GWS 850 CE angle grinder (06013787AC). The grinder worked and the speed control worked too. Several months have passed since the last time the grinder was turned on. This week I wanted to cut something in the plastic element, and here is an unpleasant surprise - the grinder does not show any signs of life. I turned it on, the photos below show how the individual elements are connected. I found a Bosch schematic of this hardware and am a little confused. I think the connections in my grinder are different than in the diagram. And now I don't know if I can make the connection as shown in the diagram. :

1. If the connection in the device worked, is it correct or acceptable?
a) for example: the regulator from diagram (No. 51), wire D (red, photo 1) in my device is connected where in the diagram the G wire is to be connected to the brush, and importantly, wire D (red) in my device, it looks like it has a pre-tightened bar and it will definitely not reach where the diagram shows (i.e. to the switch position D on the diagram),
b) cable C from the stator according to the diagram is to be connected to the switch, and in my case it is to the pin on the speed controller next to the G cable (in photo 1 next to the black one on the controller),
c) from the speed controller in my grinder, the G cable is connected where the diagram shows position E and F on the switch, and not to the "upper" brush, as in the diagram,
d) I do not know whether to list further, it seems to me that the photos are legible (unfortunately the person / s who would like to help would have to carry out such an analysis based on the photos and diagram posted, an analysis from which, unfortunately, I am not currently able to draw some constructive conclusions).

2. In the diagram, there is an alternative capacitor (item 12 in the diagram), and I am not. Could it really not be?

"I would give my head" that I did not lend anyone a grinder and since it is in my hands, nothing has been "buried" in it.

Since the grinder worked, the wires did not switch during the storage, I bet on a suspended brush, dirty commutator, or no contact on the power cord or switch, first check the voltages one by one and I would leave the diagram at the black end (maybe it's from a different version of this model?)

The contacts are clean and so is the commutator. I unscrewed the switch: if not pressed, it is open on one of the contacts (there are two groups of contacts of two), if pressed, it is closed on all contacts.
As the grinder is connected to electricity, the tester everywhere shows the voltage whether the switch is on or not.

In that case, it seems to me that somewhere something is wrongly connected and I do not give my head that in the "meantime" someone has not messed with it.

The Bosch diagram is correct for several models, for mine too (indication after the end of the model at the speed controller in the diagram), but due to some (short) wires of the regulator, it is possible that there is also a different connection method (and maybe they used one at the assembly plant) .

kaletea wrote:

As the grinder is connected to electricity, the tester everywhere shows the voltage whether the switch is on or not.

Give the grinder to the service, because the fact that you check the sampler indicates that you do not have any knowledge in this topic and you will sooner hurt yourself than find a fault.
There is a saying: let the shoemaker make shoes, the tailor sews clothes, etc., and nothing has lost its relevance and confirms the known wisdom for years.

I have a second similar Bosch GWS 850 C grinder (without speed control).

From the GWS 850 CE grinder I disassembled the switch and the speed regulator, from the GWS 850 C grinder I dismantled the switch, a system similar to the speed regulator (without the speed knob) and a capacitor. I swapped places (I put the gut from one to the other and vice versa) and connected it as it was in the original location. I turned on one. It works. I turned on the second. It works. Speed control? Yes it works. I was glad.

I reconnected everything as it was at the beginning. The one without revolutions, the GWS 850 C, works. The one with regulation (GWS 850 CE) no.

Yes, I can change places and be glad that I have a working grinding machine with revolutions, but ... there is some reason for the problem.

??????

Yesterday I turned on the grinder and ... it works. I moved it a little and it stopped with the power on. Yes, twice and now I am not observing the symptoms described. I still don't know what it could be. Something with a switch?

Check the power cord carefully (you should do it at the beginning), but not with neon - but the best solution is service (taking into account your knowledge and the time you have devoted) and during this time do what you know best to earn money for the repair.

I checked the cable with a meter for a break at the very beginning. Yes, I am not an electronics engineer, but I managed to fix some power tools (minor faults). And now the most important ... the fault was actually in the power cord.
The socket to which I connected the grinder is with a flap. In one of the two positions of the plug in the socket, the flap presses the cable just behind the plug (the force is small, but at this point the cable is a bit more punctured and that was enough). There are power failures in this position. Power cord to be replaced.

Thanks to everyone for your help.

Subject to be closed.

The cable does not work with a meter, which will not always show a break in it. The cable during the use of a power tool is subjected to various stresses and then this defect becomes visible and this is what I meant by giving you advice in my post

The solution as in my earlier post.