Hi all

I just got a 4004 and when I press start then 45 but the tone arm stops at the 33 size?

Thanks

Roy

If the 4004 works like my 4002, you should just press start after placing a 33 rpm LP or a 45 rpm single on the deck.  The deck will start at 33 rpm, then move the tonearm over and sense with a light whether you have an LP or single on the platter.  (Is your platter original?  Are you using an aftermarket mat on the platter?  Is the light on the tonearm working?)

If the deck senses the LP, the tonearm will drop in the lead in groove.  If the deck does not sense an LP, it will continue moving toward the single, speed up to 45 rpm automatically, then drop the tonearm into the lead in groove when the light senses the single.

If this is not how your deck works, post some pictures.

I press start and it will stop at 33 and drop the tone arm with the 45 on the platter. I just pulled the covers off, it happened with covers on.

I found this pic on Condoraudio and it shows a lamp light. On my TT that lamp never lights. I put my meter on it and it reads open. What type of lamp is it?

In some deck types (there are countless versions) it is an infrared LED, which would obviously be invisible in operation, and will show open on resistance measurement. Try looking at it with a cell phone camera, you might see it lit up then.

If you can confirm that it is instead an incandescent bulb and doesn't light, it needs to be replaced. It should glow when ever the table is turning.

Anyway, if the arm works automatically on 33, I think you can forget about this particular sensor for now, as it is apparently working. Do you have a light at the sensor arm (with the B&O logo)?

yes there is light at the end of the sensor arm. and also this (see pic) light is on. Again this pic is from Condoraudio.com

Have you got a meter? Are you comfortable taking measurements and following a circuit diagram?

Could be a loose connection between sensor / detector circuit, the detector circuit itself (dry joints / faulty capacitor etc.), the sensor (a small PV cell) or something else.

Yes I have a meter, and other test equipment. I don't have a good circuit diagram. But I'm very good at following directions. what does the one light do (its out on my 4004), the one that shines throught the clear (with lines)plastic ruler.

i checked the lamp and it is indeed working, checked it with my camera and it has a glow.

That is a postion detector, and tells the beogram where the start point of a 33 / 45 record is. This is not your problem as the beogram is landing on the 33 spot which is why you should ignore this. This ruler, along with the sensor arm is like an AND gate. If both points are 'active' while the arm traverses the record then that marks the point where the arm should drop.

Now, the fact that your arm is dropping at the 33 point clearly means the deck cannot, for whatever reason see the pulses from the sensor arm. So, the fault is most likely somewhere between the sensor and output of the detector circuit.

Before you look here though, is there a nice clear spot of light on the platter below the sensor arm?

There is a spot of light.

Not sure if that is an effect of the exposure as the arm moves across just check there is a plastic lens assemby under there also try moving lamp up / down to see if you can tighten the beam up a little???

with a mirror I looked at it and it looks like 2 bubble lens (magnifier lens) light is coming out of 1 lens. I'm not sure what you mean about moving the lamp up / down are you saying move the whole arm up / down? or is there a way to get into the arm? The beam does look on the fat side not really a beam more like a dim round light.

A round light of 3 mm is about right, maybe a little bigger. Looks like it was the camera  exposure elongating things a little. Ok you can get into the optics by pulling the plastic insert out- get your finger behind the lens while holding the arm with your other hand and tease the thing out by pulling forward. Watch the wires so don't pull too hard or fast. Visually check the PV cell above the rear lens, make sure both wires attached but I would resist from touching. and then I would check for continuity from there to the board. I could try to measure what to expect with a meter from this cell, but a bit busy atm!!!

I'll give it a go.

black, white, blue wire have continuity with the board.

do the transistor's 1tr6 or 1tr8 have a habit of going bad?

anyone know what this means? "Rep. BL (1TR5)" I'm thinking that my problems are in the detector arm circuit. But not having a schematic I'm lost.

You really need the diagram! 1TR5 means transistor TR5 on PCB one.

yes I know what "1TR5" is, but look at the center of the pic I posted what does  "Rep. BL " mean? I have the service manual but it does not have a full schematic. I don't think anyone has a FULL schematic for this TT. I found some high ESR's on a couple of cap's so I'll replace them and see.

Rapidroy:

I have the service manual but it does not have a full schematic. I don't think anyone has a FULL schematic for this TT.

The same place where you found that document, which is stolen from this site, probably hosts other service manuals stolen from this site as well, so look for 4002 too. The 4004 is very similar to the later DC motored 4002's, with the addition of the simple remote control logic.

There are numerous minor revisions of each model, so be flexible when reading the diagrams, as the component numbers don't always match.

Rapidroy:

what does  "Rep. BL " mean?

It means to replace that component, I think. But you shouldn't blindly follow the troubleshooting diagrams, as just like any service manual, they were designed to help when these decks were new. Old age problems can manifest themselves differently, often in ways nobody could see coming decades ago. Replacing caps that are obviously faulty should be a good start.

Ultimately, you need to follow the signal from the detector arm and see where it gets lost. It can't see the ribs on the platter now, and the problem can be as basic as a too weak or optically mislocated bulb. It is unfortunately quite hard to get right without an oscilloscope. The full schematic shows oscillograms at several points in the amplifier circuit.

Firstly, it would be great if you helped this site and became a silver member (or gold with fantastic benefits) and then you would have access to the diagrams.

Now, a quick way of tracking the fault either side of the detector circuit is to disconnect the detector lamp from the circuit. I recomend removing one of the wires that terminate on the pcb near the solenoid (please insulate and safely tuck away). If the arm still drops then it is a problem with logic. If the arm does not drop it is a problem with the detector circuit.

As Mika suggested an oscilloscope is required to fault find, however testing / replacing the electros in the faulty section is possibly your only option. Just do so carefully and methodically to minimise the introduction of new faults!!

mean't to add capacitor kit is available from Martin (user name Dillen)

I disconnect the light in the arm, pressed START (nothing on platter) platter spun up to speed, tone arm moved to edge of platter and dropped tonearm at the 33 area. I picked up a couple caps that load up to tell the arm stay up or drop down, the ESR meter showed being  marginal I'll give them a try later today.

btw: I was a paid member but money is a little tight right now, I did try to pay but they don't take PayPal (I sold some stuff and my PP account has a few bucks in it).

I changed

1c19 4.7

1c20 1.0

1c21 4.7

no change in operation. darn. I like to change things one thing at a time, then test to make sure I haven't made things worse. 

I bumped up to silver membership and still no schematic?