Hacker GP42 issue

[Armbored]

I'm trying to get a Hacker GP42 working and was having the common problem associated with the trip pawl being affected with old grease. I managed to get the cam wheel dislodged and cleaned it up, now it's clean and the pawls are loose and move freely. I struggled to get the cam wheel off and hope I have not damaged the spindle it sits on too much, as now there is some play and it's a little loose. However, the cam wheel sits on it quite nicely and I reassembled everything. I cleaned the tonearm levers and connections underneath and it's much more free than previously. Motor seems to be running well and the speeds change cleanly.

Now to the problem; when you engage the Auto function, the platter slows down to a stop. If you rotate the platter with your fingers, it will get up to speed again, but rather than the arm start the auto cycle, the operation lever jumps back to OFF and the unit shuts down. I don't know if the trip pawl is the issue, I cannot find anything else that seems to be wrong with it. Any help would be appreciated.

[Nickthedentist]

Hello,

The slowing may be due to the rubber intermediate wheel slipping. Ensure that the motor pulley, wheel edge and inside surface of the inner platter are entirely grease-free.

As for the switching off, the deck is presumably thinking there's no record present. Could you tell us what deck is fitted (the 2025TC was common but others are also found) and how you are loading records onto it etc.

Nick.

[Edward Huggins]

Yes, they sometimes fitted the (better) Garrard 3000/3500 as well as the SP25. There are plenty of "Stickys" on this site that go into more detail to help the OP. Does anyone remember if the Celestion 10" x 6" loudspeaker on the Hacker GP42 was a twin-cone unit? Edward

[julie_m]

Originally Posted by Armbored

when you engage the Auto function, the platter slows down to a stop. If you rotate the platter with your fingers, it will get up to speed again, but rather than the arm start the auto cycle, the operation lever jumps back to OFF and the unit shuts down.

That sounds as though you are trying to play a record which is already on the turntable. You can't do that! The record dropping down the spindle is an important part of the cycle. For one thing, a 25 or 30 cm. record strikes the measuring finger gently or hard respectively on the way down, so the mechanism knows where to land the tonearm; and for another, the overarm drops down with no records stacked on the spindle, to indicate "no more records to play".

The platter slowing down is probably due to poor contact between the rubber idler wheel and the inside of the platter. Clean the inside surface with lighter fluid (make sure this has all evaporated before allowing it back near the idler). You might also be able to spin the idler with an electric drill and expose a fresh surface with fine glasspaper.

[Armbored]

Hello all,
Thanks for your replies. When I first assembled the deck (2025 TC), it played perfectly.
I did a little more 'tidying up' and cleaning, then I assembled it and the slowing down platter materialised. There is no grease on the inner rim of the platter, but I could try roughening up the edge of the idle and cleaning the inner rim with IPA. Easy to try.
I know you have to put the record on top of the tall spindle and flick it to Auto for the cycle to begin, though I don't totally understand how the whole business works (I think it's sorcery actually). Will update you when I try this, thanks.

[Armbored]

Tried cleaning the inner rim of the platter and roughening of the idler wheel, still the same. However, I do notice that the trip pawl cam wheel is quite stiff to get moving. It seems to be resting in it's 'indent' quite securely, so I am going to look at the mechanism underneath. I am almost certain this is the issue, as once it's 'clicked' out of this rest, it's very free to move, as are the actual trip pawls. Will let you know how I get on.

[julie_m]

That'll be the culprit, then! Almost certainly just hardened grease. It will come off with a little heat and gentle persuasion. Be careful to lift it straight up so as not to bend the spindle it pivots on, and don't get any lubricant anywhere there wasn't any before.

[Armbored]

I've had the wheel off a few days ago Julie and cleaned it as much as I thought necessary. Unfortunately the cam post did get bent as it was stuck fast, and there is some wobble on it now. Going to try some super glue!
I can't work out what the resistance is when you try to turn the cam wheel by hand. Everything seems very free underneath, but when you try to turn the actual cam wheel, it's stiff to get going. It's very clean, I removed all old grease. still scratching my head on this one...

[Armbored]

Right, I have managed to cure the cam post wobble and the cycle seems to run reasonably well now. Except... the arm swings in to play what it thinks is a 7" record.
I'm not sure how the record sizing mechanism works, I know it's something to do with the flipper, but I appears to be not registering the size correctly. If you move it across by hand as the record drops, the tonearm goes to track 1 as it should.
However, the arm is not returning after the record plays, no matter what, unless you move it manually towards the spindle. I'll keep persevering.,,

[Armbored]

Update on this thread as it's always frustrating when the posts just dry up without a conclusion to an issue.

I fixed all the issues with this deck, I made an error in reassembling the trip pawl, by leaving out the intermediate circlip underneath. On the post where the pawl pivots, there should be two circlips, one above and one below the trip pawl. Once I discovered this and reassembled it, everything seemed to work perfectly. I then just had to clean it up. It also cured the problem of the platter slowing down as the main cam rotated and meshed with the platter.

All in all, good experience!