Hacker Grenadier GP45 - just purchased, repair advice needed

[Station X]

I would start by disconnecting the motor and fitting just the 750mA fuses.

If the fuses blow you have a problem with the transformer, diodes or smoothing capacitor.

Assuming the fuses don't blow, reconnect the gram motor. If the fuses now blow you have a problem with the gram motor. If so disconnect it and replace all blown fuses. With any luck the amp will work.

[Techman]

Personally I wouldn't bother replacing any parts before powering up just so long as any preliminary static checks with an ohm meter don't show up any abnormally low resistances or shorts.

Looking at the picture of your fuse it doesn't look like it's been 'frazzled', ie, blackened on the inside of the glass from blowing due to a short circuit, but rather that it perhaps just failed slowly or even from old age.

You can replace the electrolytic if it makes you feel better to do it first, but you run the risk of getting in a mess if you start replacing parts before you know if it's even capable of working. I always power up first after static checks and see what 'gives' and then deal with any faults that show up after that.

You'll soon know if the electrolytic is bad as it'll either blow the fuse, there'll be a bad 'hum' from the speakers, or its case will start to feel warm - switch off quickly if this is the case.

Good luck with it.

Edit: Post crossed with Graham.

[steve83]

Thanks guys, I really appreciate your help with this so far.

Still no fuses in the post so I ended up changing the capacitor and checking continuity throughout the power section...everything looks good, no shorts. However I also noticed a small tear in the edge of the speaker I'm starting to think I may have given myself a lot of work to try and get this back up and running again in a decent condition! Frustrating that the fuses still haven't arrived so I can't progress any further (fingers crossed for Monday)..

As well as the electrical issues, I need to:

- Hard wire a UK plug on it (I'm borrowing a friend's Hacker power cable currently)
- Refinish the wood / clean and refurbish the tolex
- Replace / repair speaker cone....Difficult to know how much it will affect the sound until I manage to get the record playing through it I imagine
- Any possible mechanical work needed on the record deck

I have taken some general pics of the inside, and the deck itself in case anyone might be able to cast an eye over it and definitely say that it's in a serious state of disrepair! There appears to be mould of some description on the silver shielding inside the unit...could this spell trouble?

[Edward Huggins]

I cannot see the centre stacking spindle for the Garrard record deck. Do be aware it cannot fully work without it. The speaker cone can easily be repaired (from the front) with tissue paper and contact adhesive e.g. Bostik.

[steve83]

Hi Edward - Thanks for the speaker cone tip. I do actually have the stacking spindle, just not shown in the pictures.

[Radio Wrangler]

Fuses DO have an eventual failure mechanism, even without excess current.

Constant current at the rated current is defined as that which takes 1000 hours to blow. On top of this although they survive surge currents to an extent, they age because of it, the metal of the wire becomes more granular and its resistance goes up and eventually it meets one surge too many.

So don't automatically assume there has to be a fault in the equipment, but do perform basic checks for anything obvious before replacing it and applying power.

Manufacturers are quite careful about specifying replacement fuses because it's important that the right ones are used, and making it clear covers their backsides in case someone puts something silly in and legal shenanigans ensue. If they don't say it's a slow or timed type, then it's fair to assume it's a normal blow type.

If you see something else in its place than it rouses suspicions that someone's had bother and tried to fix it with a less sensitive fuse.

I'd do some checks, change anything dodgy, put the specified fuse in and give it a whirl.

Some capacitors have a bulge in the rubber end, covering a pressure release valve and the thin rubber just tears if it lets go. That bump looks like it could be one, but even so the rubber there is clearly perished. It needs a new capacitor. Things may be getting a bit dry in there. It could be across a flush mounted valve which has partially let go. Time to let the whole capacitor go.

David

[steve83]

Hello everyone...just wanted to update this thread. I've spent a lot of time working on the player and am very chuffed to say that it is now fully operational!

After replacing the capacitor and fitting new fuses, the power section started up ok...adding in the motor it was very sluggish at first and then got going but wasn't stable. Pots were very crackly and stylus was knackered, after cleaning the pots and changing over to a new stylus I was getting good sound, but the mechanism for automatic play was gummed up as usual.

I stripped the turntable down as per various threads on here and Vinylengine, working through every section in turn, and managed to free it all up. She now works like a dream!

Final jobs to do are repair a small hole in the speaker, strip back and re-stain the tired wood, and wire an IEC plug into a new lanolin board. Going to be sad to see it go as it's a present for someone but already eyeing up another one for a future project for myself

Thanks everyone for all your input with this, very much appreciated.

Steve

[mhennessy]

That's good news

Looking closely at the picture of the loudspeaker, if that's the only damage present, I would leave it alone. It's not going to adversely affect the sound quality, but there's a risk that a repair attempt might make things worse. Chances are it's been like that since new - for all we know, you might have been the first person to ever take it apart.

I'm looking forward to reading about the cosmetic restoration. It might even persuade me to get on with mine. It's only been waiting for 7 years now

[Herald1360]

Originally Posted by steve83

... and wire an IEC plug into a new lanolin board...

I'd go for Paxolin or FR4 ERBGF myself

[D_S_J_R]

Loads on here and Vinyl Engine regarding servicing the Garrard deck. ALL auto Garrards of this period suffer from dried grease which turns to mostly-set araldite after all these years. The tonearm jumps backwards near side end and auto functions can be sluggish. It's *essential* to clean and lubricate the mechanism and the trip pawls on the cam (leave these clean and 'rattly' when re-assembling). I believe the cartridge here is the excellent Acos GP104 and although the stylus 'coupling fork' can harden with age, the main issue is the flexible suspension on the stylus hardening, which has an adverse effect on tracking. A new diamond stylus will sort this hopefully (the single 104 'Transcription' is fine if you don't play 78's on it).

Lovely old record players these and as for the valve equivalent in the previous GP42, the amplifier is very well designed, beautifully made I recall and quite possibly 'proper' HiFi quality in isolation within it's power output... When we moved here in 2004, I needed to pass on my own GP42 which Dad had been storing up until his passing. It was still working fine, had a replacement AT60 deck inside with low hours GP96 cartridge and at auction, the thing went for a fiver

[steve83]

Almost there now! Racing to get it ready for tomorrow. Been working on it all day today:

To start with I took the lid and front wooden frame off (thankfully yes the wooden frame DOES separate from the grille and metal piping, was worried about that) and stripped them back to bare wood with medium / fine paper and finally fine steel wool. Masked over the tolex on the lid for this and thankfully it held and no damage was caused...didn't fancy having to re-cover that on top of everything else!

I'm using tung oil for the refinish, and am very happy - it's come up better than I hoped. So far I'm three coats in (the brand I'm using needs 4h30 between coats) and I have one final application to do before I call it a night.

For the speaker - whennessy I've already repaired it...will report back and let you know how it sounds. Hope I've not made it worse! Managed a pretty clean job with some tissue paper and diluted bostik as per lots of googling.

I also created a new paxolin board (not lanolin ) and mounted the IEC, with in-line fuse holder cases as I couldn't find anything better anywhere nearby. Annoyingly I had to make a new back cover plate as there wasn't room to mount the IEC far enough to the left to make it accessible through the existing round hole. Bit of a bodge job with only a hacksaw and drill but got there in the end.

Finally some brasso worked wonders on the hinges and the multi player spindle.

So all that's left is to leave the wood to dry overnight and then put it all back together tomorrow! I'll post some final pictures of the finished job when it's all in one piece.

[mhennessy]

Sounds encouraging - though I hope you kept the wire wool well away from the loudspeaker! It's awful stuff, and wrecks speakers - seen it happen countless times.

[steve83]

Hey guys - here's a few pics showing the original casing against the refinished case after using tung oil. Also you can see the reworked power section with in-line fuse casings and a replacement IEC connector board.

I'm very happy with how it came out. It took a couple of attempts at putting everything back together as the wood frame is no longer true so I had to be careful how everything was retightened to try and get the bolts to 'hold' it as much as possible.

In general I'm really chuffed with the results although after having not been used for a few days the motor was a little sluggish to get going and needed a little nudge on the turntable to start turning. Also there is a bit of wobble on the pitch - I've found a handy iphone app which uses its built in gyroscope to analyse the stability and it looks like there is about a 1.5% deviation above 33rpm. When viewed as a graph it is always in the same part of the turntable's cycle that the speed up occurs, and is gradual (looks like a mountain shape drawn). I imagine this could be due to a number of things. My plan is to have a closer look at the motor first (I only degreased and re-oiled it from above), also to remove the rubber idler and strip down and rebuild (I cleaned it up and added a dab of oil to its spindle but didn't strip it as it seemed to be functioning OK). I also didn't de-gunk the underside of the deck as the work I did from above (including the trip pawl and turntable spindle / bearings etc) seemed at the time to have done the trick.

Any thoughts would be appreciated as ever! It seems almost there now but I want to get it 100% before I put it to bed.

[Edward Huggins]

That 1.5% speed variation you quote is well within the limits of such a budget turntable as your Garrard 2025TC. Many are much worse. There is little you can do to change this. Do nothing to the idler wheel, increasing or decreasing its diameter, will make no difference. BTW I notice you do not have the overarm set correcly on your 3rd photo.

[steve83]

Ah really? Would you mind elaborating on what's incorrectly set? Are you referring to the position of the overarm?

Also regarding the pitch wobble - it's definitely audible, especially with any music containing sustained notes/chords. Surely this isn't within expected tolerances? With it being a regular cyclical wobble, I figured it must be caused by something on either the idler wheel or the turntable, and perhaps not helped by a weak motor.

[mhennessy]

Yes, I read it as wow (variations) rather than a fixed 1.5% error. Definitely worthy of further investigation.

Looking really good there. Lovely job on the cosmetics. It would be worth considering protecting the mains inlet with one of these: http://cpc.farnell.com/pro-elec/dip-...f-2/dp/PL07005

(Link is to the first example I found - I've no idea if it will fit your chosen IEC socket)

What are the clear plastic things - are they in-line fuseholders? If so, what are they doing, given that the mains inlet is already fused? You only need to fuse the Live - indeed today, fusing the Neutral as well is no longer done, as it's considered less safe to do so.

Based on that, I think the original brown and blue wires can go straight to the rear of the IEC connector (and boot ).

Again, nice job

[Edward Huggins]

Yes, I read this originally as meaning a 1.5% fixed deviation from the expected speed.

I realise now that the OP is referring to Wow (he says "Wobble") which does suggest a deformed idler wheel. It can be returned to new condition by just a quick skim on a lathe.