7424 high speed issues

[chetmoseley]

Ok first let me say I have used my PC alot. Only on personal vehicles but I would say it gets used a few hours a month on something of mine or a family members. I've had the pc for 3 or so years.

Last night I purchased a new to me (2005) Chevrolet truck with moderate scratches on the truck. Went to tackle the job with menz 1500 and microfiber pad. To gain results I Was having to use heavy pressure and high speed (this technique is used often with my corvette and the hard clear coat) I was very very impressed at some of the scratches and marking I was able to remove on this truck. I did year up one Mf pad and it delaminates on me.

During the later half of use. The PC would not spin under any pressure on high speeds. It seemed if I would reduce the speed to one and back to 6 I could then apply pressure again. I had to baby this while finishing my panel then I called it quits.

Any thoughts or ideas

[chetmoseley]

Anyone?

[ken tuep]

It might be time to upgrade to a griots, or something with more power. The brushes might also need to be replaced.

[rmagnus]

Sounds like an issue with the dial on the PC. I do not consider your PC heavly used but they are tools and all tools develope problems. Take the backing plate off and inspect. My guess is there is a worn electrical connection in the dial. SInce it's out of warranty you might try ordering a replacement dial and installing it yourself or take it to a tool repair shop have have them diagnose it for repair.

The PC is a nice buffer but about the weakest in the DA line up. If you were to update and get a new one try the GG.

Can anyone else offer help?

[erichaley]

Mine actually does the opposite. Below speed 5, it acts like its on speed 1. Hit speed 5, and its like someone lit a rocket!

I replaced the speed switch, but it didn't make a difference.

You could try replacing the switch and see if it fixes your issue. It has worked for others.

BTW, the switch is really cheap, and replacing it is super simple. No electrical experience is required.

[inDetail]

you may be applying too much pressure overall in the past bogging it down perhaps between 9 and 14 pounds is all you need let the pads and polish do the work

[lawrenceSA]

Mine actually does the opposite. Below speed 5, it acts like its on speed 1. Hit speed 5, and its like someone lit a rocket!

I replaced the speed switch, but it didn't make a difference.

You could try replacing the switch and see if it fixes your issue. It has worked for others.

BTW, the switch is really cheap, and replacing it is super simple. No electrical experience is required.

This sounds to me like your brushes are not making proper contact with the commutator and need to be replaced. When on the highest speed setting the increased voltage could be allowing the electricity to arc from the brush to the commutator (and thus the machine works) but on the lower speed settings, there is insufficient voltage to allow the jump across the gap.

My educated guess?

[CharlzO]

Mine actually does the opposite. Below speed 5, it acts like its on speed 1. Hit speed 5, and its like someone lit a rocket!

I replaced the speed switch, but it didn't make a difference.

You could try replacing the switch and see if it fixes your issue. It has worked for others.

BTW, the switch is really cheap, and replacing it is super simple. No electrical experience is required.

Mine does exactly the same. I can get almost no movement with any pressure at all unless I turn it to 6. The worst part, is I've had it for exactly a day. It was this way right out of the box. Had originally forgotten the washer, thought maybe that was part of it, so I fixed that, but still nothing. On 5, it's "eh", 6 is fine, but anything else, it feels pretty useless. Was hoping maybe it was normal for using the MF pads to have that reaction, but watching countless videos seems to point more towards an issue with the unit. Sucks, since it's brand new, and I hate to have to wait to get it replaced, or repaired - which I guess we'll see what happens when I call about it this weekend. I guess I'll peek at it and see if there's anything obvious? Never had one of these so I'm not even sure what I'm looking at lol.